Researcher Database

Researcher Profile and Settings

Master

Affiliation (Master)

  • Institute of Low Temperature Science Pan-Okhotsk Research Center

Affiliation (Master)

  • Institute of Low Temperature Science Pan-Okhotsk Research Center

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Profile and Settings

Degree

  • Master in Environmental Science(Hokkaido University)
  • Doctor in Environmental Science(Hokkaido University)

Profile and Settings

  • Name (Japanese)

    Shiraiwa
  • Name (Kana)

    Takayuki
  • Name

    200901054844695145

Alternate Names

Achievement

Research Interests

  • 環境   古気候   氷河   雪氷   Environment   Paleo climate   Glacier   Glaciology   

Research Areas

  • Natural sciences / Atmospheric and hydrospheric science
  • Humanities & social sciences / Geography

Education

  • 1989/04 - 1990/12  北海道大学大学院
  • 1987/04 - 1989  Hokkaido University
  • 1983/04 - 1987/03  Waseda University  School of Education

Published Papers

  • Shungo Fukumoto, Shin Sugiyama, Shuntaro Hata, Jun Saito, Takayuki Shiraiwa, Humio Mitsudera
    Journal of Glaciology 1 - 14 0022-1430 2022/07/04 [Refereed]
     
    Abstract On the Kamchatka Peninsula in the Russian Far East, 405 glaciers with an estimated total mass of 49 Gt were reported in the 1970s. These have been retreating at an accelerated rate since the start of the 21st century. Because glacier studies in this region are scarce, ice loss and its influence on sea level rise and regional environments is poorly understood. In this study, we analyzed satellite data to quantify glacier mass change from 2000 to 2016 in six major glacier-covered regions on the peninsula. The mean rate of the glacier mass change over the study period was −0.46 ± 0.01 m w.e. a−1 (total mass change was −4.9 ± 0.1 Gt, −304.2 ± 9.1 Mt a−1), which is slightly lower than other regions in mid-latitude and subarctic zones. The mass loss accelerated from >−0.33 ± 0.02 m w.e. a−1 in the period 2000–2006/2010 to <−1.65 ± 0.12 m w.e. a−1 in 2006/2010–2015/16. The increase in mass loss is attributed to a rise in average decadal summer temperatures observed in the region (+0.68°C from 1987–99 to 2000–13). Moreover, a recent trend in Pacific decadal oscillation suggests future acceleration of mass loss due to a decline in winter precipitation.
  • Yuto Tashiro, Muneoki Yoh, Vladimir Shesterkin, Takayuki Shiraiwa, Takeo Onishi, Daisuke Naito
    2022/05/31 [Refereed]
  • Muqing Shi, Takayuki Shiraiwa, Humio Mitsudera, Yaroslav Muravyev
    JOURNAL OF HYDROLOGY-REGIONAL STUDIES 36 2021/08 [Refereed]
     
    Study Region: Kamchatka Peninsula, Russian Federation.Study Focus: The strength of an overturning process of North Pacific sea water originating in the Sea of Okhotsk is determined by the sea water salinity in the area. Recent observations show that the overturning process is important to the entire North Pacific and is statistically related to the precipitation over the Kamchatka Peninsula (KP). This study uses estimations based on specific discharge and the Soil and Water Assessment Tool (SWAT) to verify and further explore the connection between the terrestrial freshwater discharge from KP and the overturning process.New Hydrological Insights for the Region: Previously inaccessible observed discharge data from 11 major rivers on the KP were obtained and analyzed for the first time. Based on the data we estimate annual discharge from the entire KP using the specific discharge and regression analysis, and we then simulate monthly discharge from the western KP using the SWAT model. Our result shows a significant negative correlation (r(2) = 0.36, p < 0.01) between the interannual variation of sea water salinity in the overturning process area, and the variation of annual freshwater discharge from the western KP, therefore successfully verifies that freshwater discharge from the western KP is a critical factor that affects the strength of the overturning process.
  • Yuto Tashiro, Muneoki Yoh, Takayuki Shiraiwa, Takeo Onishi, Vladimir Shesterkin, Vladimir Kim
    WATER 12 (9) 2020/09 [Refereed]
     
    Dissolved iron (dFe) in boreal rivers may play an important role in primary production in high-latitude oceans. However, iron behavior in soils and dFe discharge mechanism from soil to the rivers are poorly understood. To better understand iron dynamics on the watershed scale, we observed the seasonal changes in dFe and Dissolved Organic Carbon (DOC) concentrations in the river as well as dFe concentration in soil pore waters in permafrost watershed from May to October. During snowmelt season, high dFe production (1.38-4.70 mg L-1) was observed in surface soil pore waters. Correspondingly, riverine dFe and DOC concentrations increased to 1.10 mg L-1 and 32.3 mg L-1, and both were the highest in the year. After spring floods, riverine dFe and DOC concentrations decreased to 0.15 mg L-1 and 7.62 mg L-1, and dFe concentration in surface soil pore waters also decreased to 0.20-1.28 mg L-1. In late July, riverine dFe and DOC concentrations increased to 0.33 mg L-1 and 23.6 mg L-1 in response to heavy rainfall. In August and September, considerable increases in dFe concentrations (2.00-6.90 mg L-1) were observed in subsurface soil pore waters, probably because infiltrated rainwater developed reducing conditions. This dFe production was confirmed widely in permafrost wetlands in valley areas. Overall, permafrost wetlands in valley areas are hotspots of dFe production and greatly contribute to dFe and DOC discharge to rivers, especially during snowmelt and rainy seasons.
  • Ambarish Pokhrel, Kimitaka Kawamura, Bhagawati Kunwar, Kaori Ono, Akane Tsushima, Osamu Seki, Sumio Matoba, Takayuki Shiraiwa
    ATMOSPHERIC CHEMISTRY AND PHYSICS 20 (1) 597 - 612 1680-7316 2020/01 [Refereed]
     
    A 180m long (343 years) ice core was drilled in the saddle of Aurora Peak in Alaska (63.52 degrees N, 146.54 degrees W; elevation: 2825 m) and studied for biomass-burning tracers. Concentrations of levoglucosan and dehydroabietic and vanillic acids exhibit multidecadal variability, with higher spikes in 1678, 1692, 1695, 1716, 1750, 1764, 1756, 1834, 1898, 1913, 1966 and 2005 CE. Historical trends of these compounds showed enhanced biomass-burning activities in the deciduous broadleaf forests, boreal conifer forests, and/or tundra woodland and mountain ecosystems before the 1830s and after the Great Pacific Climate Shift (GPCS). The gradually elevated level of dehydroabietic acid after the GPCS is similar to p-hydroxybenzoic acid (p-HBA) from the Svalbard ice core, suggesting common climate variability in the Northern Hemisphere. The periodic cycle of levoglucosan, which seemed to be associated with the Pacific Decadal Oscillation (PDO), may be more involved with the longrange atmospheric transport than other species. These compounds showed significant correlations with global lowertropospheric temperature anomalies (GLTTAs). The relations of the biomass-burning tracers with the PDO and GLTTA in this study suggest that their emission, frequency and deposition are controlled by the climate-driven forces. In addition, historical trends of dehydroabietic and vanillic acids (burning products of resin and lignin, respectively) from our ice core demonstrate the Northern Hemispheric connections to the common source regions as suggested from other ice core studies from Svalbard, Akademii Nauk and Tunu Greenland in the Northern Hemisphere.
  • Takayuki Shiraiwa
    NIPPON SUISAN GAKKAISHI 83 (6) 1011 - 1011 0021-5392 2017 [Not refereed]
  • Hirotaka Sasaki, Sumito Matoba, Takayuki Shiraiwa, Carl S. Benson
    SOLA 12 287 - 290 1349-6476 2016/11 [Refereed][Not invited]
     
    To quantify the atmospheric iron deposition on the northern North Pacific region, we measured concentrations of iron in ice cores drilled at Mount Wrangell, Alaska, in 2003 and 2004. The iron concentration profile from 1981 to 2003 showed seasonal peaks each spring. This variation was similar to the seasonal variation in the concentration of mineral dust in the atmosphere in the North Pacific region. The annual iron fluxes calculated from the ice core records ranged from 3.2 to 27.0 mg m(-2) yr(-1), and the temporal variation in the iron lux was significantly correlated with the frequency of severe dust storms occurrence on the East Asian continent (r = 0.65, p < 0.05) and the total number of Kosa days observed in Japan (r = 0.64-0.66, p < 0.05), but not with the precipitation amount in Alaska. We concluded that the amount of iron deposition onto the northern North Pacific is controlled mainly by the emission of dust from the east Asian continent and not by scavenging processes in Alaska.
  • Pingqing Fu, Kimitaka Kawamura, Osamu Seki, Yusuke Izawa, Takayuki Shiraiwa, Kirsti Ashworth
    ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 3 (10) 351 - 358 2328-8930 2016/10 [Refereed][Not invited]
     
    Biogenic secondary organic aerosol (SOA) is ubiquitous in the Earth's atmosphere, influencing climate and air quality. However, the historical trend of biogenic SOA is not well known. Here, we report for the first time the major isoprene- and monoterpene-derived SOA tracers preserved in an ice core from the Kamchatka Peninsula. Significant variations are recorded during the past 300 years with lower concentrations in the early-to-middle 19th century and higher concentrations in the preindustrial period and the present day. We discovered that isoprene SOA tracers were more abundant in the preindustrial period than the present day, while monoterpene SOA tracers stay almost unchanged. The causes of the observed variability are complex, depending on atmospheric circulation, changes in emissions, and other factors such as tropospheric oxidative capacity. Our data presents an unprecedented opportunity to shed light on the formation, evolution, and fate of atmospheric aerosols and to constrain the uncertainties associated with modeling their atmospheric concentrations.
  • Ambarish Pokhrel, Kimitaka Kawamura, Kaori Ono, Osamu Seki, Pingqing Fu, Sumio Matoba, Takayuki Shiraiwa
    ATMOSPHERIC ENVIRONMENT 130 105 - 112 1352-2310 2016/04 [Refereed][Not invited]
     
    Monoterpene and isoprene secondary organic aerosol (SOA) tracers are reported for the first time in an Alaskan ice core to better understand the biological source strength before and after the industrial revolution in the Northern Hemisphere. We found significantly high concentrations of monoterpene- and isoprene-SOA tracers (e.g., pinic, pinonic, and 2-methylglyceric acids, 2-methylthreitol and 2-methylerythritol) in the ice core, which show historical trends with good correlation to each other since 1660s. They show positive correlations with sugar compounds (e.g., mannitol, fructose, glucose, inositol and sucrose), and anti-correlations with alpha-dicarbonyls (glyoxal and methylglyoxal) and fatty acids (e.g., C-18:1) in the same ice core. These results suggest similar sources and transport pathways for monoterpene- and isoprene-SOA tracers. In addition, we found that concentrations of C-5-alkene triols (e.g., 3-methyl-2,3,4-trihydroxy-1-butene, cis-2-methyl 1,3,4-trihydroxy-1-butene and trans-2-methyl-1,3,4-trihydroxy-1-butene) in the ice core have increased after the Great Pacific Climate Shift (late 1970s). They show positive correlations with a-dicarbonyls and fatty acids (e.g., C-18:1) in the ice core, suggesting that enhanced oceanic emissions of biogenic organic compounds through the marine boundary layer are recorded in the ice core from Alaska. Photochemical oxidation process for these monoterpene- and isoprene-/sesquiterpene-SOA tracers are suggested to be linked with the periodicity of multi-decadal climate oscillations and retreat of sea ice in the Northern Hemisphere. (C) 2015 Elsevier Ltd. All rights reserved.
  • 大西 健夫, 楊 宗興, 白岩 孝行, 長尾 誠也
    低温科学 北海道大学低温科学研究所 74 13 - 20 1880-7593 2016 [Not refereed][Not invited]
     
    アムール川流域からは高濃度の溶存鉄が供給され,オホーツク海の生物生産に深く関与していることが示唆されている.溶存鉄の生物地球科学的プロセスには未解明な点もあるが,流域というマクロな視点にもとづき経験的な生成量予測モデル構築に成功した.しかし,1990年代後半に溶存鉄濃度の急激な上昇が観測され,この要因は解明されていない.このメカニズム解明には複数の要因が関わっていると考えられるが,永久凍土の挙動が深く関わっている可能性が高い.観測とモデリングを通しての溶存鉄生成メカニズムの解明を考察する.
  • Yu Ohata, Takenobu Toyota, Takayuki Shiraiwa
    JOURNAL OF GLACIOLOGY 62 (233) 563 - 578 0022-1430 2016 [Refereed]
     
    Lake-ice properties at Lake Abashiri, Hokkaido, Japan, were examined using field observations and a 1-D thermodynamic model to clarify formation processes at mid-latitudes subject to significant snowfall as well as moderate air temperature. At all lake sites examined, the ice comprised two distinct layers: a snow ice (SI) layer on top and a congelation ice (CI) layer below. The SI layer occupied as much as 29-73% of the total ice thickness, a much greater fraction than that reported for lakes at Arctic high latitudes. In the model, the CI growth rate was estimated using the traditional heat budget method, while the SI growth rate was calculated assuming the excessive snowfall from the isostatic balance is converted to SI by a snow compression rate (beta) with the surface melting rate added when the surface heat budget becomes positive. By tuning the value of beta to the observational results of SI thickness, the model outcome successfully reproduced the observational thicknesses of CI and SI, and the break-up date of the lake. Essentially, the model findings show how snow and its formation into SI reduce, by about half, the seasonal variability of total ice thickness.
  • Seki Osamu, Kawamura Kimitaka, Bendle James A. P, Izawa Yusuke, Suzuki Ikuko, Shiraiwa Takayuki, Fujii Yoshiyuki
    SCIENTIFIC REPORTS 5 2045-2322 2015/09/28 [Refereed][Not invited]
     
    Carbonaceous aerosols influence the climate via direct and indirect effects on radiative balance. However, the factors controlling the emissions, transport and role of carbonaceous aerosols in the climate system are highly uncertain. Here we investigate organic tracers in ice cores from Greenland and Kamchatka and find that, throughout the period covered by the records (1550 to 2000 CE), the concentrations and composition of biomass burning-, soil bacterial-and plant wax-tracers correspond to Arctic and regional temperatures as well as the warm season Arctic Oscillation (AO) over multi-decadal time-scales. Specifically, order of magnitude decreases (increases) in abundances of ice-core organic tracers, likely representing significant decreases (increases) in the atmospheric loading of carbonaceous aerosols, occur during colder (warmer) phases in the high latitudinal Northern Hemisphere. This raises questions about causality and possible carbonaceous aerosol feedback mechanisms. Our work opens new avenues for ice core research. Translating concentrations of organic tracers (mu g/kg-ice or TOC) from ice-cores, into estimates of the atmospheric loading of carbonaceous aerosols (mu g/m(3)) combined with new model constraints on the strength and sign of climate forcing by carbonaceous aerosols should be a priority for future research.
  • Ohata Yu, Toyota Takenobu, Shiraiwa Takayuki
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会/日本雪工学会 2015 33 - 33 2015
  • A. Tsushima, S. Matoba, T. Shiraiwa, S. Okamoto, H. Sasaki, D. J. Solie, K. Yoshikawa
    CLIMATE OF THE PAST 11 (2) 217 - 226 1814-9324 2015 [Refereed][Not invited]
     
    A 180.17m ice core was drilled at Aurora Peak in the central part of the Alaska Range, Alaska, in 2008 to allow reconstruction of centennial-scale climate change in the northern North Pacific. The 10m depth temperature in the borehole was -2.2 degrees C, which corresponded to the annual mean air temperature at the drilling site. In this ice core, there were many melt-refreeze layers due to high temperature and/or strong insolation during summer seasons. We analyzed stable hydrogen isotopes (delta D) and chemical species in the ice core. The ice core age was determined by annual counts of delta D and seasonal cycles of Na+, and we used reference horizons of tritium peaks in 1963 and 1964, major volcanic eruptions of Mount Spurr in 1992 and Mount Katmai in 1912, and a large forest fire in 2004 as age controls. Here, we show that the chronology of the Aurora Peak ice core from 95.61m to the top corresponds to the period from 1900 to the summer season of 2008, with a dating error of +/- 3 years. We estimated that the mean accumulation rate from 1997 to 2007 (except for 2004) was 2.04mw.eq.yr(-1). Our results suggest that temporal variations in delta D and annual accumulation rates are strongly related to shifts in the Pacific Decadal Oscillation index (PDOI). The remarkable increase in annual precipitation since the 1970s has likely been the result of enhanced storm activity associated with shifts in the PDOI during winter in the Gulf of Alaska.
  • Ambarish Pokhrel, Kimitaka Kawamura, Osamu Seki, Sumio Matoba, Takayuki Shiraiwa
    ATMOSPHERIC ENVIRONMENT 100 202 - 209 1352-2310 2015/01 [Refereed]
     
    An ice core drilled at Aurora Peak in southeast Alaska was analyzed for homologous series of straight chain fatty acids (C-12:0-C-30:0) including unsaturated fatty acid (oleic acid) using gas chromatography (GC/FID) and GC/mass spectrometry (GC/MS). Molecular distributions of fatty acids are characterized by even carbon number predominance with a peak at palmitic acid (C-16:0, av. 20.3 +/- SD. 29.8 ng/g-ice) followed by oleic acid (C-18:1, 19.6 +/- 38.6 ng/g-ice) and myristic acid (C-14:0, 15.3 +/- 21.9 ng/g-ice). The historical trends of short-chain fatty acids, together with correlation analysis with inorganic ions and organic tracers suggest that short-chain fatty acids (except for C-12:0 and C-15:0) were mainly derived from sea surface micro layers through bubble bursting mechanism and transported over the glacier through the atmosphere. This atmospheric transport process is suggested to be linked with Kamchatka ice core SD record from Northeast Asia and Greenland Temperature Anomaly (GTA). In contrast, long-chain fatty acids (C-20.0-C-30:0) are originated from terrestrial higher plants, soil organic matter and dusts, which are also linked with GTA. Hence, this study suggests that Alaskan fatty acids are strongly influenced by Pacific Decadal Oscillation/North Pacific Gyre Oscillation and/or extra tropical North Pacific surface climate and Arctic oscillation. We also found that decadal scale variability of C-18:1/C-18:0 ratios in the Aurora Peak ice core correlate with the Kamchatka ice core SD, which reflects climate oscillations in the North Pacific. This study suggests that photochemical aging of organic aerosols could be controlled by climate periodicity. (C) 2014 Elsevier Ltd. All rights reserved.
  • Jun Nishioka, Takeshi Nakatsuka, Kazuya Ono, Yu. N. Volkov, Alexey Scherbinin, Takayuki Shiraiwa
    PROGRESS IN OCEANOGRAPHY 126 180 - 193 0079-6611 2014/08 [Refereed]
     
    Comprehensive observations of the iron (Fe) distribution in the western Sea of Okhotsk were conducted and revealed the existence of two Fe transport processes in the sub-polar marginal sea. One transport process is Fe loading from the Amur River and transport by the East Sakhalin Current (ESC), and the other is Fe transport by the intermediate water (part of which was reported by Nishioka et al., 2007). Here, we report on quantitative evaluations of these two Fe transport processes. The surface dissolved Fe (Diss-Fe) and low salinity water distribution clearly indicate the influence of Fe discharge from the Amur River and the Fe that is transported by the East Sakhalin Current. The amounts of total dissolvable Fe (TD-Fe) and Diss-Fe that cross the surface of the northeast Sakhalin coastal area are estimated at 9.0 x 10(8) - similar to 1.3 x 10(9) g yr(-1) and 1.0 x 10(8) similar to 1.5 x 10(8) g yr(-1), respectively. Although the ESC surface transport system along the Sakhalin coast is effective, the length-scale estimation of TD-Fe transport indicated that only 1.5% of the Fe at the mouth of the Amur River reached 52 degrees N, which may be due to scavenging by biological particulates. High Fe anomalies were observed at the bottom of the continental shelf and the shelf break along the Sakhalin coast. The extremely low temperature and low N* water indicate that Fe resuspension due to the reducing properties of sediment occurred on the shelf and that the Fe was introduced to Dense Shelf Water (DSW) by tidal mixing. We estimate that the amounts of TD-Fe and Diss-Fe involved in the DSW on the continental shelf are 8.8 x 10(10) similar to 2.5 x 10(11) g yr(-1) and 2.3 x 10(9) - similar to 6.6 x 10(9) g yr(-1), respectively. Length-scale estimates of TD-Fe transport indicate that 20% of the TD-Fe on the continental shelf remained in the Kuril Basin; thus, the TD-Fe in the intermediate water was efficiently transported to the Kuril Basin. These results indicate that two orders of magnitude more Fe is derived from the continental shelf by the intermediate water than by surface water and that Fe is transported a greater distance by intermediate water than by the surface layer. Additionally, the Fe that reached the Kuril Straits was mixed by intensive tidal mixing and influenced the vertical profiles of the water columns on both sides of the Kuril Straits in the Kuril Basin and the Oyashio region. Our quantitative evaluation also indicates other Fe inputs around the Kuril Strait. (C) 2014 Elsevier Ltd. All rights reserved.
  • Tatsuru Sato, Takayuki Shiraiwa, Ralf Greve, Hakime Seddik, Erik Edelmann, Thomas Zwinger
    Climate of the Past 10 (1) 393 - 404 1814-9324 2014/02 [Refereed][Not invited]
     
    An ice core was retrieved in June 1998 from the Gorshkov crater glacier at the top of the Ushkovsky volcano, in central Kamchatka. This ice core is one of only two recovered from Kamchatka so far, thus filling a gap in the regional instrumental climate network. Hydrogen isotope (δD) analyses and past accumulation reconstructions were conducted for the top 140.7 m of the core, spanning 1736-1997. Two accumulation reconstruction methods were developed and applied with the Salamatin and the Elmer/Ice firn-ice dynamics models, revealing a slightly increasing or nearly stable trend, respectively. Wavelet analysis shows that the ice core records have significant decadal and multi-decadal variabilities at different times. Around 1880 the multi-decadal variability of δD became lost and its average value increased by 6%. The multi-decadal variability of reconstructed accumulation rates changed at around 1850. Reconstructed accumulation variations agree with ages of moraines in Kamchatka. Ice core signals were significantly correlated with North Pacific sea surface temperature (SST) and surface temperature (2 m temperature). δD correlates with the North Pacific Gyre Oscillation (NPGO) index after the climate regime shift in 1976/1977, but not before that. Therefore, our findings imply that the ice core record contains various information on the local, regional and large-scale climate variability in the North Pacific region. Understanding all detailed mechanisms behind the time-dependent connections between these climate patterns is challenging and requires further efforts towards multi-proxy analysis and climate modelling.
  • Sumito Matoba, Kunio Shimbori, Takayuki Shiraiwa
    ANNALS OF GLACIOLOGY 55 (68) 83 - 87 0260-3055 2014 [Refereed][Not invited]
     
    The Institute of Low Temperature Science at Hokkaido University conducted ice-core drilling in alpine glaciers in the northern North Pacific region to reconstruct climate change in this region for the past few hundred years. We drilled two ice cores in the Kamchatka Peninsula, Russia. An ice core with a length of 211 m was drilled on a glacier at the summit caldera of Ushkovsky mountain in 1998. A second core, with a length of 115 m (until bedrock was reached), was drilled on a glacier at the summit caldera of Ichinsky mountain in 2006. We drilled three further ice cores in Alaska, USA. Two ice cores with lengths of 50 and 212 m were drilled on a glacier at the summit caldera of Mount Wrangell in 2003 and 2004. The third ice core was drilled on the ice divide among three glaciers, Black Rapids, Trident and Susitna glaciers, which represent a flat saddle north of Aurora Peak in the Alaska Range. This paper details the field operations and characteristics of the different ice-drilling systems used and the problems encountered.
  • Nishioka Jun, Nakatsuka Takeshi, Watanabe Yutaka W, Yasuda Ichiro, Kuma Kenshi, Ogawa Hiroshi, Ebuchi Naoto, Scherbinin Alexey, Volkov Yuri N, Shiraiwa Takayuki, Wakatsuchi Masaaki
    GLOBAL BIOGEOCHEMICAL CYCLES Amer geophysical union 27 (3) 920 - 929 0886-6236 2013/09 [Refereed][Not invited]
     
    The subarctic Pacific is a high-nutrient low-chlorophyll (HNLC) region in which phytoplankton growth is broadly limited by iron (Fe) availability. However, even with Fe limitation, the western subarctic Pacific (WSP) has significant phytoplankton growth and greater seasonal variability in lower trophic levels than the eastern subarctic Pacific. Therefore, differences in Fe supply must explain the west-to-east decrease in seasonal phytoplankton growth. The Fe flux to the euphotic zone in the WSP occurs at a moderate value, in that it is significantly higher than its value on the eastern side, yet it is not sufficient enough to cause widespread macronutrient depletion, that is, HNLC status is maintained. Although we recognize several Fe supply processes in the WSP, the mechanisms that account for this moderate value of Fe supply have not previously been explained. Here we demonstrate the pivotal role of tidal mixing in the Kuril Islands chain (KIC) for determining the moderate value. A basin-scale meridional Fe section shows that Fe derived from sediments in the Sea of Okhotsk is discharged through the KIC into the intermediate water masses (similar to 800m) of the western North Pacific. The redistribution of this Fe-rich intermediate water by intensive mixing as it crosses the KIC is the predominant process determining the ratio of micronutrient (Fe) to macronutrients (e.g., nitrate) in subsurface waters. This ratio can quantitatively explain the differences in surface macronutrient consumption between the western and eastern subarctic, as well as the general formation and biogeochemistry of HNLC waters of the subarctic North Pacific.
  • OHATA YU, SHIRAIWA TAKAYUKI
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会/日本雪工学会 2013 38  1883-0870 2013
  • Kimitaka Kawamura, Yusuke Izawa, Michihiro Mochida, Takayuki Shiraiwa
    GEOCHIMICA ET COSMOCHIMICA ACTA 99 317 - 329 0016-7037 2012/12 [Refereed]
     
    We successfully detected biomass burning tracers including levoglucosan and vanillic, p-hydroxybenzoic and dehydroabietic acids in an ice core (153 m long, ca. 300 years old) taken from Ushkovsky ice cap (altitude, 3903 m), the Kamchatka Peninsula, Northeast Asia. Concentrations of total organic carbon (TOC) were also determined in the ice core. Levoglucosan, which is produced by pyrolysis of cellulose and hemicellulose and thus is a general tracer of biomass burning, showed sporadic peaks in the years of 1705, 1759, 1883, 1915, 1949 and 1972, with the largest peak in 1949. However, its concentrations did not show a systematic increase in the last century although the concentration peaks seemingly corresponded to the higher ambient temperatures in the northern high latitudes. In contrast, dehydroabietic acid, a specific tracer of the pyrolysis of conifer resin, showed a gradual increase from the early 1900s to 1990s with a significant peak in 1970. Contributions of dehydroabietic acid to TOC also showed an increasing trend for the 20th century. Similarly, vanillic and p-hydroxybenzoic acids presented higher concentrations in the last half-century with sporadic peaks in 1705, 1759 and 1949. This study showed that general biomass burning tracers such as levoglucosan have been sporadically transported over the glacier of the Kamchatka Peninsula. In contrast, the ice core record of dehydroabietic acid indicated that fires of boreal conifer forest have more frequently and increasingly occurred in Far East and Siberia during the last century and transported to the Northwestern Pacific. The present study demonstrates that organic tracers of biomass burning preserved in ice core could provide historical records of biomass burning and boreal forest fires. (C) 2012 Elsevier Ltd. All rights reserved.
  • Shiraiwa Takayuki
    Proceedings of the General Meeting of the Association of Japanese Geographers 公益社団法人 日本地理学会 2012s 100086  2012 
    It was found that the Amur River basin could be considered as a giant "fish-breeding forest" for the Sea of Okhotsk and Oyashio openwater by suppling dissolved iron. It is an essential element for the photosynthesis of phytoplankton and the sufficient supply of dissolved iron makes the Sea of Okhotsk and Oyashio openwater as one of the world richest oceans.
  • Takehiro Fukuda, Shin Sugiyama, Sumito Matoba, Takayuki Shiraiwa
    ANNALS OF GLACIOLOGY 52 (58) 138 - 142 0260-3055 2011 [Refereed]
     
    As part of a deep ice-core drilling project, GPS and ice-radar measurements were made in the vicinity of Aurora Peak, Alaska, USA. Surface and bed elevation maps were obtained over an area of 400 m x 700 m, which includes the drilling site. Surface flow velocity was measured at 18 locations in the same area. The results showed that the drilling site was situated on a gentle north-south ridge with saddle-shaped surface geometry. The horizontal ice-flow velocity at the drilling site was <0.5 m a(-1) and the ice generally flowed eastward and westward along the surface slope. The glacier bed slopes to the east and has more complex topography than the ice surface. The drilling site was situated above a bedrock dip, with an ice thickness of 252 +/- 10 m. These data constitute important information for estimating the effect of ice flow to the ice core retrieved from the depth of up to 180.17 m.
  • Sumito Matoba, Takayuki Shiraiwa, Akane Tsushima, Hirotaka Sasaki, Yaroslav D. Muravyev
    ANNALS OF GLACIOLOGY 52 (58) 44 - 50 0260-3055 2011 [Refereed][Not invited]
     
    The Sea of Okhotsk is the southernmost area in the Northern Hemisphere where seasonal sea ice is produced every year. The formation of sea ice drives thermohaline circulation in the Sea of Okhotsk, and this circulation supports the high productivity in the region. However, recent reports have indicated that sea-ice production in the Sea of Okhotsk is decreasing, raising concern that the decreased sea ice will affect not only circulation but also biological productivity in the sea. To reconstruct climatic changes in the Sea of Okhotsk region, we analyzed an ice core obtained from Ichinskaya Sopka (Mount Ichinsky), Kamchatka. We assumed that the remarkable negative peaks of delta D in the ice core were caused by expansion of sea ice in the Sea of Okhotsk. Melt feature percentage (MFP), which indicates summer snowmelt, showed high values in the 1950-60s and the mid-1990s-2000s. The high MFP in the 1950-60s was assumed to be caused by an increase in cyclone activity reaching Kamchatka during a negative period of the Pacific Decadal Oscillation index, and that in the 1990-2000s may reflect the increase in solar irradiation during a positive period of the summer Arctic Oscillation index.
  • 春山 成子, シャーモフ V. V, 川東 正幸, GANZEY Sergey, ERMOSHIN Victor, MISHINA Natalia, 近藤 昭彦, 増田 佳孝, LE Hailan, 室岡 瑞恵, 柿澤 宏昭, 白岩 孝行, 朴 紅, 山根 正伸, 立花 義弘, 大島 和弘, 小木 雅代, SHAMAKIN Andrey B, 氷見山 幸夫, YAN Baixing, PAN Xiaofeng, PAN Yuepeng, 大西 健夫, 楊 宗興, 柴田 英昭, 長尾 誠也
    E-journal GEO 公益社団法人 日本地理学会 4 (2) 138 - 144 1880-8107 2010 [Not refereed][Not invited]
  • 白岩 孝行
    境界研究 北海道大学スラブ研究センター内 グローバルCOEプログラム「境界研究の拠点形成:スラブ・ユーラシアと世界」 (1) 181 - 185 2185-6117 2010
  • Shiraiwa Takayuki
    Proceedings of the General Meeting of the Association of Japanese Geographers 公益社団法人 日本地理学会 2009s 235 - 235 2009 
    The Amur River basin was found to play a key role in supporting primary production in the Oyashio region of the western subarctic Pacific Ocean by supplying dissolved iron which was essential element for phytoplankton growth. Because the dissolved iron mainly forms as a complex of iron and fuluvic acids originating from forests and swamps in the Amur River basin, it is likely that land-cover changes in the Amur River basin may affect primary production in the Sea of Okhotsk and the Oyashio region. The land-ocean linkage mention above reminds us of the Japanese concept of Uotsuki-rin (the fish-breeding forest). However, the Amur-Okhotsk-Oyashio linkage is much stronger than that in the conventional concept. More importantly, this is the first attempt to relate the continental-scale terrestrial environment with open waters. Therefore, we refer to the idea as "Kyodai" Uotsuki-rin kasetsu (the "Giant" Fish-Breeding Forest (GFBF) Hypothesis). We have conducted various kinds of scientific researches to verify the hypothesis since 2005 and we considers it was nearly done at present. The GFBF is also recognized as a natural system that transport various nutrients, trace elements like dissolved iron, and pollutants from an upper area (i.e., the Amur River basin) to a lower area (the Sea of Okhotsk and Oyashio region). Fluxes of such materials can fluctuate significantly owing to various human activities including agriculture, forestry and industry. The human activities are then influenced by both local and international sociological, political and economic situations with which the lower stakeholders are closely related. Therefore, it is also possible to recognize the GFBF as a social system connecting various stakeholders beyond the national boundaries by cycling materials, information and properties. In spite of its importance and uniqueness, there has been no framework for protecting/conserving the GFBF. This is mainly due to the geopolitical situation of the Amur River basin and the Sea of Okhotsk: the long-term political tensions in the area have hidden the environmental deterioration from the public. We would like to inform domestic and international communities of the GFBF and its importance. We will then propose an agenda for the conservation of the GFBF by collaborating with Russian and Chinese scientists by the end of fiscal year 2009.
  • Kohshima S., Scheihing R., Jaramillo J., Shiraiwa Takayuki, Matoba Sumito, Kanda D., Labarca P., Casassa G.
    Journal of Glaciology International Glaciological Society 54 (186) 452 - 462 0022-1430 2008/07 [Refereed]
     
    The first analyses of biological components in glaciers of the Chilean lake district are presented based on microalgae biovolume, pollen and other microorganisms detected in shallow ( 10 m) firn/ice cores. Three cores were retrieved, two at Volca´n Mocho-Choshuenco (398550 S, 728020W; summit at 2422ma.s.l; east glacier at 2000ma.s.l.), and one at the summit of Volca´n Osorno (418060 S, 728300W; 2652ma.s.l.). Microalgae, protozoa and pollen quantified in the samples obtained from the two summit cores show clear fluctuations interpreted as seasonal signs. In contrast, dD and many chemical species from the summit cores show strong dampening at depth, probably due to water percolation. The limited information provided by isotopic and chemical analyses is used to support the seasonal interpretation of biological parameters from the summit cores, with microorganism maxima inferred to occur in summer and pollen maxima in spring. A good comparison is found between massbalance estimations from the Volca´n Mocho-Choshuenco summit core and values obtained near that site by means of the stake method. It is concluded that biological analyses of firn/ice cores provide reliable estimations of annual and seasonal markers from these temperate glaciers.
  • Syosaku Kanamori, Carl S. Benson, Martin Truffer, Sumito Matoba, Daniel J. Solie, Takayuki Shiraiwa
    JOURNAL OF GLACIOLOGY 54 (185) 273 - 278 0022-1430 2008 [Refereed]
     
    We recorded the burial times of temperature sensors mounted on a specially constructed tower to determine snow accumulation during individual storms in the summit caldera of Mount Wrangell, Alaska, USA, (62 degrees N, 144 degrees W; 4100 m a.s.l.) during the accumulation year June 2005 to June 2006. The experiment showed most of the accumulation occurred in episodic large storms, and half of the total accumulation was delivered in late summer. The timing of individual events correlated well with storms recorded upwind, at Cordova, the closest Pacific coastal weather station (200 km south-southeast), although the magnitude of events showed only poor correlation. Hence, snow accumulation at Mount Wrangell appears to be a reflection of synoptic-scale regional weather systems. The accumulation at Mount Wrangell's summit (>2.5 m w.e.) exceeded the precipitation at Cordova. Although the direct relationship between accumulation of individual storms at the summit of Mount Wrangell and precipitation events at Cordova may be unique in the region, it is useful for interpreting ice cores obtained on Mount Wrangell. This is especially the case here because the high rate of accumulation allows high time resolution within the core.
  • Yamaguchi Satoru, Naruse Renji, Shiraiwa Takayuki
    JOURNAL OF GLACIOLOGY International Glaciological Society 54 (184) 125 - 130 0022-1430 2008 [Refereed][Not invited]
     
    Based on the field data at Koryto glacier, Kamchatka Peninsula, Russia, we constructed a one-dimensional numerical glacier model which fits the behaviour of the glacier. The analysis of meteorological data from the nearby station suggests that the recent rapid retreat of the glacier since the mid-20th century is likely to be due to a decrease in winter precipitation. Using the geographical data of the glacier terminus variations from 1711 to 1930, we reconstructed the fluctuation in the equilibriumline altitude by means of the glacier model.With summer temperatures inferred from tree-ring data, the model suggests that the winter precipitation from the mid-19th to the early 20th century was about 10% less than that at present. This trend is close to consistent with ice-core results from the nearby ice cap in the central Kamchatka Peninsula.
  • Teppei J. Yasunari, Takayuki Shiraiwa, Syosaku Kanamori, Yoshiyuki Fujii, Makoto Igarashi, Koji Yamazaki, Carl S. Benson, Takeo Hondoh
    JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 112 (D10) 2169-897X 2007/05 [Refereed][Not invited]
     
    [1] The North Pacific is subject to various seasonal climate phenomena and material circulations. Therefore intra-annual ice core data are necessary for an assessment of the climate variations. To assess past variations, a 50-m ice core was drilled at the summit of Mount Wrangell Volcano, Alaska. The dust number, tritium concentrations, and stable hydrogen isotope were analyzed. The period covered was from 1992 to 2002. We found that the concentrations of both fine dust (0.52 - 1.00 mu m), an indicator of long-range transport, and coarse dust (1.00 - 8.00 mu m) increased together every spring. Moreover, their concentrations increased drastically after 2000, corresponding to the recent increase in Asian dust outbreaks in spring. Additionally, an increase in the spring of 2001 corresponded to the largest dust storm recorded in east Asia since 1979. Therefore our findings imply that Asian dust strongly polluted Mount Wrangell every spring. The stratospheric tracer, tritium, had late spring maxima almost every year, and we found this useful for ice core dating to identify late spring in the North Pacific region. We also found that a high positive annual correlation existed between the calculated tritium and fine dust fluxes from late spring to summer. We propose that an annual relationship between the stratosphere-troposphere exchange and Asian dust storm are most closely connected in late spring because their activities are weak in summer. The Mount Wrangell ice core is important and useful for assessing the dust and tritium circulation in the distant past around the North Pacific with probable intra-annual timescale information.
  • KANAMORI Syosaku, SHIRAIWA Takayuki, MATOBA Sumito, YASUNARI Teppei
    Preprints of the Annual Conference, Japanese Society of Snow and Ice 公益社団法人 日本雪氷学会 2007 2 - 2 0919-7346 2007
  • Matoba Sumito, Ushakov Sergey V., Shimbori Kunio, Sasaki Hirotaka, Yamasaki Tetsuhide, Ovshannikov Alexander A., Manevich Alexander G., Zhideleeva Tatyana M., Kutuzov Stanislav, Muravyev Yaroslav D., Shiraiwa Takayuki
    Bulletin of Glaciological Research Japanese Society of Snow and Ice 24 79 - 85 1345-3807 2007/01 [Refereed]
     
    During summer 2006, we carried out ice-core drilling to bedrock on a glacier at the summit of Mount Ichinsky, Kamchatka, Russia, and recovered a 115-m-long ice core. We also prepared samples, performed ice-core analyses in-situ, and measured the borehole temperature. The temperature of the borehole was -13℃ at 10m depth, and the pore close-off depth was 25m. The melt-feature percentage, or the thickness of frozen ice layers in a 1-m-long section of ice core, varied from 10% to 100%. These ice layers were formed by both rainfall, surface melting, and frost on the glacier surface, which we observed during our expedition. We hypothesize that the fluctuations in the proportion of ice layers show climatic variation in Kamchatka.
  • Thomas Zwinger, Ralf Greve, Olivier Gagliardini, Takayuki Shiraiwa, Mikko Lyly
    ANNALS OF GLACIOLOGY, VOL 45, 2007 45 29 - + 0260-3055 2007 [Refereed]
     
    The Gorshkov crater glacier at Ushkovsky volcano, Kamchatka, is characterized by a large aspect ratio and special thermodynamic conditions at the bedrock caused by a locally enhanced and spatially varying geothermal heat flux. Furthermore, large parts of this glacier consist of firn rather than pure ice, which alters the rheological properties (such as viscosity and compressibility) of the glacier. We present a newly developed, thermo-mechanically coupled, three-dimensional flow model based on the finite-element (FE) modeling software Elmer, and apply it to the Gorshkov crater glacier. By assuming steady-state conditions, the present-day velocity field, temperature field, basal melting rate and age distribution are simulated. We find that flow velocities are generally small (tens of centimeters per year). Horizontal and vertical velocities are of comparable magnitude, which shows that the shallow-ice approximation is not applicable. Owing to the spatially variable volcanic heat flux, the thermal regime at the ice base is cold in the deeper parts of the glacier and temperate in the shallower parts. The measured temperature profile and age horizons at the K2 borehole are reproduced quite well, and remaining discrepancies may be attributed to transient (non-steady-state) conditions. Firn compressibility is identified as a crucial element for the modeling approach.
  • Shiro Kohshima, Nozomu Takeuchi, Jun Uetake, Takayuki Shiraiwa, Ryu Uemura, Naohiro Yoshida, Sumito Matoba, Maria Angelica Godoi
    Global and Planetary Change 59 (1-4) 236 - 244 0921-8181 2006 [Refereed][Not invited]
     
    Snow algae in a 45.97-m-long ice core from the Tyndall Glacier (50°59′05″S, 73°31′12″W, 1756 m a.s.l.) in the Southern Patagonian Icefield were examined for potential use in ice core dating and estimation of the net accumulation rate. The core was subjected to visual stratigraphic observation and bulk density measurements in the field, and later to analyses of snow algal biomass, water isotopes (18O, D), and major dissolved ions. The ice core contained many algal cells that belonged to two species of snow algae growing in the snow near the surface: Chloromonas sp. and an unknown green algal species. Algal biomass and major dissolved ions (Na+, K+, Mg2+, Ca2+, Cl-, SO42-) exhibited rapid decreases in the upper 3 m, probably owing to melt water elution and/or decomposition of algal cells. However, seasonal cycles were still found for the snow algal biomass,18O, D-excess, and major ions, although the amplitudes of the cycles decreased with depth. Supposing that the layers with almost no snow algae were the winter layers without the melt water essential to algal growth, we estimated that the net accumulation rate at this location was 12.9 m a- 1from winter 1998 to winter 1999, and 5.1 m from the beginning of winter to December 1999. These estimates are similar to the values estimated from the peaks of18O (17.8 m a- 1from summer 1998 to summer 1999 and 11.0 m from summer to December 1999) and those of D-excess (14.7 m a- 1from fall 1998 to fall 1999 and 8.6 m a- 1from fall to December 1999). These values are much higher than those obtained by past ice core studies in Patagonia, but are of the same order of magnitude as those predicted from various observations at ablation areas of Patagonian glaciers. © 2006 Elsevier B.V. All rights reserved.
  • SHIRAIWA Takayuki
    Landslides The Japan Landslide Society 41 (2) 198 - 201 1348-3986 2004
  • Regional characteristics of surface snow chemistry at East Dronning Maud Land, Antarctica
    Motoyama, H, K. Kamiyama, T. Shiraiwa, T. Saito, T. Kameda, N. Azuma, S. Fujita, Y. Fujii, K. Suzuki, T. Yamada, T. Suzuki, Y. Iizuka, T. Furukawa, K. Nishimura, S. Kanamori, O. Watanabe
    Seventh International Symposium on Antarctic Glaciology 11  2003/08/01 [Not refereed][Not invited]
  • Hondoh Takeo, Narita Hideki, Hori Akira, Ikeda-Fukazawa Tomoko, Fujii-Miyamoto Michiko, Ohno Hiroshi, Shiraiwa Takayuki, Mae Shinji, Fujita Shuji, Fukazawa Hiroshi, Fukumura Taku, Shoji Hitoshi, Kameda Takao, Miyamoto Atsushi, Azuma Nobuhiko, Wang Yun, Kawada Kunio, Nishio Fumihiko, Motoyama Hideaki, Watanabe Okitsugu
    Memoirs of National Institute of Polar Research. Special issue 57 63 - 71 2003/03 [Refereed][Not invited]
     
    Recent results of physical analyses of the Dome Fuji ice core are summarized with special attention to new methods introduced in the present studies. Microphysical processes which affect the ice core records are reviewed to better understand the paleoclimatic and paleoenvironmental signals stored.
  • T Shiraiwa, S Kohshima, R Uemura, N Yoshida, S Matoba, J Uetake, MA Godoi
    ANNALS OF GLACIOLOGY, VOL 35 35 84 - 90 0260-3055 2002 [Refereed]
     
    A 45.97 in long ice core was recovered in the accumulation area of Glaciar Tyndall (50degrees59'05" S, 73degrees31'12" W, 1756 in a.s.l.), Campo de Hielo Patagonico Sur (southern Patagonia icefield), during December 1999. The firn core was subjected to visual stratigraphic observation and bulk density measurements in the field, and later to analyses of water isotopes (delta(18)O, deltaD), major dissolved ions and snow algal biomass. The drillhole remained dry down to about 43 in depth, where a water-soaked layer appeared. Seasonal cycles were found for delta(18)O, deltaD and the D-excess, although the amplitudes of the cycles decreased with depth. Major dissolved ions (Na+, K+, Mg2+, Ca2+, Cl-, SO42-) and algal biomass exhibit rapid decreases in the upper 3 in, probably due to meltwater elution. Annual increments defined by the 518 0 and D-excess peaks suggest that the minimum net accumulation rates at this location were 17.8 in a(-1) in 1997/98-1998/99 and > 11.0 in a(-1) in 1998/99-1999/2000. These are much higher values than those previously obtained from past ice-core studies in Patagonia, but are of the same order of magnitude as those predicted from various observations in ablation areas of Patagonian glaciers.
  • Study of physical properties of ice cores and ice sheet dynamics, Deep ice coring project at Dome Fuji
    Takeo Hondoh, Hideki Narita, Takayuki Shiraiwa, Tomoko Ikeda-Fukazawa, Michiko Fujii, Hiroshi Ohno, Shinji Mae, Hiroshi Fukazawa, Taku Fukumura, Nobuhiko Azuma, Yun Wong, Hitoshi Shoji, Takao Kameda, Atsushi Miyamoto, Kunio Kawada, Ayako Abe, Fuyuki Saito, Okitsugu Watanabe, Hideaki Motoyama
    Antarctica Progress Report 2002 17-21  2002/01 [Not refereed][Not invited]
  • Fuji, Y, N. Azuma, Y.Tanaka, Y. Nakayama, T. Kameda, K. Shinbori, K. Katagiri, S. Fujita, A. Takahashi, K. Kawada, H. Motoyama, H. Narita, K. Kamiyama, T. Furukawa, S. Takahashi, H. Shoji, H. Enomoto, T. Saitoh, M. Miyahara, R. Naruse, T. Hondoh, T. Shiraiwa, K. Yokoyama, Y. Ageta, T. Saito, O. Watanabe
    Memoirs of National Institute of Polar Research, Special Issue, 56 (56) 103 - 116 2002 [Refereed][Not invited]
     
    Deep ice core drilling was carried out at Dome Fuji, Antarctica in 1995 and 1996 from the bottom of the casing installed in 1993 and reached 2503.52m in December 1996. We used a JARE type electromechanical drill with a core barrel of 2.2m length. Total numbers of ice corings and chip collections were 1369 and 837 respectively. The mean coring depths per run and per day were 1.75m and 8.21m, respectively. Quality of ice cores was perfect throughout the whole depth, even in the brittle zone. We report the outline of the system, coring performance, and troubles encountered.
  • TAKEUCHI Nozomu, KOHSHIMA Shiro, SHIRAIWA Takayuki, KUBOTA Keiji
    Bulletin of glaciological research 18 65 - 69 1345-3807 2001/03/01
  • Takayuki Shiraiwa, Yaroslav D. Murav'yev, Takao Kameda, Fumihiko Nishio, Yoko Toyama, Akiyoshi Takahashi, Alexander A. Ovsyannikov, Andrey N. Salamatin, Kotaro Yamagata
    Journal of Glaciology 47 (158) 423 - 432 0022-1430 2001 [Refereed][Not invited]
     
    A glacier at the summit of Ushkovsky volcano, Kamchatka peninsula, Russia, was studied in order to obtain information about the physical characteristics of a glacier that fills a volcanic crater. The glacier has a gentle surface and a concave basal profile with a maximum measured depth of 240 m at site of K2. The annual accumulation rate was 0.54 m a-1 w.e., and the 10 m depth temperature was-15.8°C. A 211.70 m long ice core drilled at K2 indicates that (1) the site is categorized as a percolation zone, (2) the stress field in the glacier changes at 180 m depth from vertical and longitudinal compression with transversal extension, which is divergent flow, to a shear-dominated stress field, and (3) the frequent occurrence of ash layers can be a good tool for dating the ice core. The borehole temperature profiles were considered to be non-stationary, but the linear profile made it possible to estimate the basal temperature and the geothermal heat flux at K2. Assuming constant surface and the basal boundary conditions, we constructed two depth-age relationships at K2. These predicted that the bottom ages of the ice core were about 511 or 603 years.
  • Y Iizuka, H Satake, T Shiraiwa, R Naruse
    JOURNAL OF GLACIOLOGY 47 (157) 223 - 231 0022-1430 2001 [Refereed][Not invited]
     
    Debris-laden basal ice is exposed along an ice cliff near Hamna Glacier, Soya Coast, East Antarctica. The basal ice is about 6.8 in thick and shows conspicuous stratigraphic features. The upper 5.5 in consists of alternating layers of bubble-free and bubbly ice. delta values of the bubble-free ice layers are enriched by 2.4 +/- 1.0 parts per thousand (standard deviation) for delta O-18 compared to values of neighboring bubbly ice layers above, and slopes of delta O-18 vs deltaD are close to 8. Such layers are suggested to have been formed by refreezing of meltwater in an open system. In contrast, part of the bubbly ice layers shows neutral profiles for stable isotopes, suggesting that these ice masses are undisturbed ice-sheet ice which was not affected by melting and freezing. The massive alternating layers are thus considered to have been formed by folding of refrozen and non-melted layers. The lower 1.3 m consists predominantly of bubble-free massive ice. The profile of co-isotopic values shows a change of about 3.0 parts per thousand for delta O-18 at the interface between bubble-free and bubbly ice. Since the isotopic change occurred over a wider thickness than the upper 5.5 in, the basal ice is suggested to have been formed by refreezing of meltwater on a larger scale than the upper 5.5 m.
  • Iizuka Yoshinori, Igarashi Makoto, Shiraiwa Takayuki, Naruse Renji, Yamada Tomomi, Watanabe Okitsugu
    Polar meteorology and glaciology 国立極地研究所 14 8 - 15 1344-3437 2000 [Refereed][Not invited]
     
    Debris-laden basal ice is exposed along an ice cliff (about 30m high) near Hamna Icefall, Soya Coast, East Antarctica. The basal ice about 6.8m thick can be divided into an upper part (5.5m) and a lower part (1.3m) based on stratigraphic features. Major dissolved ions of the basal ice are probably composed of eight species (Na^+, K^+, Mg^<2+>, Ca^<2+>, Cl, SO_4^2,NO_3 and HCO_3). Almost all Na^+, K^+, Mg^<2+>, Ca^<2+>, SO_4^2 and HCO_3 in the basal ice are considered to have originated from chemical erosion of rock minerals at the base of the ice sheet. According to a calculation of ion composition, the primary rock mineral dissolved in the basal ice is considered to be carbonate.
  • H Enomoto, H Motoyama, T Shiraiwa, T Saito, T Kameda, T Furukawa, S Takahashi, Y Kodama, O Watanabe
    JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 103 (D18) 23103 - 23111 2169-897X 1998/09 [Refereed][Not invited]
     
    An abrupt warming was observed in the winter around Dome Fuji (3810 m above sea level (asl)) in East Antarctica. The air temperature increased from -73 degrees C to -36 degrees C in two days, from June 13 to 14, 1994. Warming occurred first in the coastal region near the Lambert Glacier, East Antarctica, then progressed inland to Dome Fuji. During the warming, a blocking high was observed in the middle troposphere and it persisted for several weeks. This circulation pattern brought warm air inland. A blocking high over East Antarctica also appeared in the upper troposphere; this high-pressure area corresponded to a ridge of stratospheric circulation. This condition occurred after a displacement of the polar vortex from East Antarctica to West Antarctica. Warming at the surface of the ice sheet occurred suddenly; however, in the stratosphere the circulation pattern began to change on a seasonal scale prior to the warming as part of the first phase of the semiannual oscillation.
  • SONE Toshio, SHIRAIWA Takayuki, KITAHARA Tomoyuki
    Annals of The Tohoku Geographycal Asocciation The Tohoku Geographical Association 50 (3) 201 - 207 0916-7889 1998/08/31 
    Downslope stone movements were measured on stone-banked lobes in a nivation hollow on the Daisetsu Mountains. Surface stones were painted on three lobes with gradients of 27, 22, 12 degrees in September, 1989. Displacements of the painted stones were measured in October 1991 and 1997.
    The deformation features of painted lines showed lobe and tongue like patterns. The average rates of the movements were higher in the central part of the lobes, ranging from 4.5 to 9.2cm/year, while those in the marginal part ranged from 0.5 to 4.5cm/year. Stones moved uniformly with little disturbance of configuration in the marginal part. But stones were scattered in the central part. Smaller stones tended to be moved farther.
  • O. Watanabe, K. Kamiyama, H. Motoyama, M. Igarashi, S. Matoba, T. Shiraiwa, T. Yamada, H. Shoji, S. Kanamori, N. Kanamori, M. Nakawo, Y. Ageta, S. Koga, K. Satow
    Proc. of the NIPR Symp. Polar Meteorol. and Glaciol. 国立極地研究所 11 14 - 23 0914-2037 1997 [Refereed][Not invited]
     
    An ice core from the glacier surface down to 112.59m depth was obtained in 1993 at Dome Fuji Station. The ice core was divided vertically in the home cold laboratory and various analyses were carried out for the solid and liquid phases of core samples. The measurements of numbers of microparticles, electrical conductivity, pH, oxygen isotopic ratio and chemical constituents were carried out for the melted ice core samples. In this report, the procedures and the methods for the measurements are introduced with results obtained. The results open preliminary step on ice core research at Dome Fuji Station, which should be useful to evaluate the environments at the dome in the comparison with core analyses at various sites. The vertical distributions for the some of the values obtained are presented to facilitate further discussion of the past climate and environments.
  • Kameda, T, S. Takahashi, H. Enomoto, N. Azuma, T. Shiraiwa, Y. Kodama, T. Furukawa, O. Watanabe, G. A. Weidner, C. R. Stearns
    Proc. NIPR Symp. Polar Meteorol. Glaciol. 国立極地研究所 11 (11) 35 - 50 0914-2037 1997 [Refereed][Not invited]
     
    This paper focuses on instrumentation and observational results of eight Automatic Weather Station (AWS) units in East Queen Maud Land, Antarctica 1995. The AWS units were installed at six sites on the ice sheet from coast to inland : the site nearest to the coast (H21) was located at 60km at 1076m altitude and a site farthest from the coast (Dome Fuji Station) was located about 920km inland at 3810m altitude. Two types of AWS units (CMOS and ARGOS) were employed. Air temperatures at H21 and Dome Fuji Station change from +2.3 to -44.4℃ and -23.3 to -80.1℃, respectively. Monthly mean July temperatures in eight AWS data are systematically higher than June and August temperatures, respectively. During the period of temperature increase in July, atmospheric pressure also increased. Wind speed during the whole period could only be obtained at MD180 at which glazed surface was observed. Prevailing wind (south-east : SE) at Relay Point covers 40% of the total wind direction, and wind from the east north-east slightly prevails (11%) at Dome Fuji Station. Atmospheric pressure at Relay Point drops in May and September, and increases in July and December. Monthly mean lapse rates on snow surface were calculated using AWS data. Annaul mean lapse rates obtained by the AWS data were systematically lower than that obtained by 10m snow temperatures in Mizuho Plateau. Increase of temperature difference between air and snow surface with altitude will be a reason for the phenomenon.

MISC

  • Yoh Yamashita, Akihide Kasai, Takayuki Shiraiwa, Yoshihisa Shirayama  NIPPON SUISAN GAKKAISHI  83-  (6)  1008  -1008  2017  [Not refereed]
  • 西岡純, 三寺史夫, 白岩孝行, 関宰, 中村知裕, 的場澄人, 江淵直人  低温科学  74-  175  -180  2016/03/31  [Not refereed][Not invited]
     
    日本は,オホーツク海,日本海,東シナ海といった「縁辺海」と「北太平洋」に面しており,太平洋からみると縁辺海と大洋を隔てる列島の一部である.さらにベーリング海を含めたこれら北太平洋の縁辺海は,自然科学的視点からみても,人間活動の場として見ても多くの共通性と特異性を持ち合わせている.これらのすべての縁辺海には,大河川や,規模は小さいが数多くの中・小河川が流れ込むことで,陸域の影響が大きく現れる.これら河川を通じて陸からの物質を受け取り,縁辺海内部で起こる様々な物理的プロセスと生物的・化学的反応を介して物質循環が活発に起こっている場所である.これらの各縁辺海は,陸域の影響を大洋に伝える間の緩衝作用も担うと同時に,大洋の影響も強く受け,物質的にも暖流(黒潮)や寒流(親潮)で結ばれている.縁辺海の自然科学的な機能を明らかにすることは,東シナ海,日本海,オホーツク海を経由して,北太平洋へと至る,長大な物質循環システムを理解することに繋がる.本稿では,環オホーツク域の「陸海結合システム」という概念に焦点を当て,環オホーツク域で進めてきた研究で残されている課題と,日本の周辺領域も含めたさらに大きなスケールで陸海結合システムをとらえるための研究展開について記す.Linkage between land and ocean is one of important issue for understanding earth system, and marginal seas are a key place for this linkage. The South China Sea, the East China Sea, the Japan Sea, the Sea of Okhotsk and the Bering Sea are marginal seas located on the north/west rim of the Pacific Ocean. These marginal seas received strong influence from the land via large and small scale river discharge, which include human influence. The marginal seashave high productivity and active biogeochemical cycles relative to those in oceanic regions, which are controlled by individual local processes, such as fresh water discharge, interior current systems, tidal mixing, local upwelling, continental shelves interactions, sea ice production/melting, and flows through straits. Further, recent studies indicated that some of the marginal seas strongly influence to the Pacific Ocean on physical and biogeochemicalprocesses. Therefore, clarifying roles of the marginal seas for linkage between land and oceanic region is one of the major remaining issue for understanding whole Pacific Ocean. In this paper, we discuss remaining issue to understand not only pan-Okhotsk biogeochemical system but also the role of Pacific marginal seas in linking adjacent land with ocean.
  • 白岩 孝行  ユーラシア研究 = Eurasian studies  (53)  27  -30  2015/12
  • Sato Tatsuru, Shiraiwa Takayuki, Greve Ralf, Zwinger Thomas, Seddik Hakime  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2009-  (0)  192  -192  2009  [Refereed][Not invited]
  • 白岩 孝行  デジタルブック最新第四紀学 記念号  2009
  • 白岩 孝行  雪氷研究の系譜 別冊  98  -101  2009
  • Fukuda, T, S. Sugiyama, T. Shiraiwa, S. Matoba  Glaciology in Hokkaido  28-  69  -72  2009  [Not refereed][Not invited]
  • 白岩 孝行  雪氷  69-  (5)  i  -ii  2007/09/15
  • Shiraiwa Takayuki  Low temperature science  65-  57  -65  2007/03/23  
    Three independent ice cores were recently drilled at Ushkovsky Volcano in Kamchatka, Russia, Mount Wrangell in Alaska, and Mount Logan King Col in Canada. Detailed analyses of the temperature and density profiles of the three cores suggest that the three sampled glaciers are cold glaciers and therefore store reliable paleo-climate information that spans the past several hundreds to a thousand years. A negative relation was found for the net accumulation time-series reconstructed for the past 170 years from the ice cores recoverd from Ushkovsky Volcano and Mount Logan. As the oscillations in the net accumulation rate and the average annual δ^18O reconstructed from the Ushkovsky ice core appear to be closely correlated with the so-called Pacific Decadal Oscillation (PDO) Index, it was suggested that the mass balances of the glaciers on both sides of the northern North Pacific were affected not only by a global warming trend since the Little Ice Age but also by inter-decadal climate variability that had occured dominantly over the North Pacific.
  • 白岩 孝行, 的場 澄人  雪氷  68-  (4)  315  -317  2006/07/15
  • 春山, 成子, 白岩, 孝行  千葉大学環境リモートセンシング研究センター年報 = Center for Environmental Remote Sensing, Annual report  11-  26  -28  2006/06  
    type:text source:Center for Environmental Remote Sensing, annual report identifier:31
  • Sato Tatsuru, Shiraiwa Takayuki, Matoba Sumito  Preprints of the Annual Conference, Japanese Society of Snow and Ice  2006-  (0)  101  -101  2006  [Refereed][Not invited]
  • 白岩 孝行  アークティック・サークル(北海道立北方民族博物館友の会・季刊誌) 59  4  -9  2006
  • 白岩孝行  雪と氷の辞典  277  -287  2005
  • SHIRAIWA Takayuki  Journal of the Japan Landslide Society  41-  (1)  79  -82  2004/05/25
  • Shiraiwa Takayuki, Takeuchi Nozomu, Azuma Kumiko  Preprints of the Annual Conference, Japanese Society of Snow and Ice  2004-  (0)  108  -108  2004  [Not refereed][Not invited]
  • GOTO AZUMA Kumiko, SHIRAIWA Takayuki, MATOBA Sumito, SEGAWA Takahiro, KANAMORI Syosaku, FUJII Yoshiyuki, YAMASAKI Tetsuhide  Bulletin of glaciological research  20-  65  -72  2003/02/01
  • SHIRAIWA Takayuki, GOTO AZUMA Kumiko, MATOBA Sumito, YAMASAKI Tetsuhide, SEGAWA Takahiro, KANAMORI Syosaku, MATSUOKA Kenichi, FUJII Yoshiyuki  Bulletin of glaciological research  20-  57  -63  2003/02/01
  • 白岩孝行, 山口悟  地学雑誌  111-  (4)  476  -485  2002/08/25  [Not refereed][Not invited]
     
    More than 400 glaciers exist in the mountains of Kamchatka Peninsula and they constitute the southern boundary of present-day glacierization along the eastern coast of the Eurasian continent. The mass balances of the glaciers are characterized by decadal and interdecadal oscillations, and they are closely related to those observed in the glaciers of Pacific North America. A negative relation was also found for the net accumulation timeseries reconstructed by ice cores from Ushkovsky Volcano, Kamchatka, and Mt. Logan, Canada, for the last 170 years. Because the oscillations of the net accumulation rate and the average annual &delta; <SUP>18</SUP>O reconstructed from Ushkovsky-ice-core seem to be closely correlated with the so-called Pacific Decadal Oscillation (PDO) Index, it was suggested that the mass balances of the glaciers at both sides of the North Pacific had been affected not only by global warming trends but also by the interdecadal climate variability that had dominantly been occurring over the North Pacific.
  • 白岩 孝行  地理  47-  (6)  74  -79  2002/06
  • Kohshima Shiro, Shiraiwa Takayuki, Godoi Maria Angelica, Kubota Keiji, Takeuchi Nozomu, Shinbori Kunio  Memoirs of National Institute of Polar Research. Special issue  56-  49  -58  2002/03  
    A 45.97m-deep drilling operation was carried out during November/December 1999 on the accumulation area of Tyndall glacier (50°59′05″S, 73°31′12″W, 1756m a. s. l.) at the southern end of the Southern Patagonia Icefield. A portable electromechanical drilling system was developed for ice-coring on temperate glaciers which often have aquifers near the pore-close off depths. The firn-core obtained was subjected to visual stratigraphic observations and bulk-density measurements. Preliminary results suggest an extremely high accumulation rate (about 12-14m a^<-1> w. e.) at the drilling site. The drilling operation was strenuous because of the continuous strong wind and enormous snowfall which forced the members to survive for nearly three weeks in a snow cave before evacuation.
  • SALAMATIN Andrey N., SHIRAIWA Takayuki, MURAVYEV Yaroslav D., ZIGANSHIN Marat F.  Bulletin of glaciological research  19-  47  -52  2002/02/01
  • YAMADA Tomomi, TAKAHASHI Shuhei, SHIRAIWA Takayuki, FUJII Yoshiyuki, KONONOV Yuriy, ANANICHEVA Maria D., KOREISHA Michael M., MURAVYEV Yaroslav D., SAMBORSKY Taras  Bulletin of glaciological research  19-  101  -106  2002/02/01
  • 白岩 孝行  雪氷  63-  (1)  97  -98  2001/01/15
  • 白岩 孝行  雪氷 : journal of the Japanese Society of Snow and Ice / 日本雪氷学会 編  62-  (4)  393  -401  2000/07
  • SHIRAIWA Takayuki  日本地理学会発表要旨集 = Proceedings of the General Meeting of the Association of Japanese Geographers  57-  136  -137  2000
  • 白岩 孝行  雪氷 : journal of the Japanese Society of Snow and Ice / 日本雪氷学会 編  61-  (4)  314  -316  1999/07  
    記事種別: 会議・学会報告・シンポジウム
  • Fujii Yoshiyuki, Azuma Nobuhiko, Tanaka Yoichi, Takahashi Akiyoshi, Shinbori Kunio, Motoyama Hideaki, Katagiri Kazuo, Fujita Shuji, Miyahara Morihiro, Nakayama Yoshiki, Kameda Takao, Saito Takashi, Saito Takeshi, Shoji Hitoshi, Shiraiwa Takayuki, Narita Hideki, Kamiayma Kokichi, Furukawa Teruo, Maeno Hideo, Enomoto Hiroyuki, Naruse Renji, Yokoyama Kotaro, Hondo Takeo, Aageta Yutaka, Kawada Kunio, Watanabe Okitsugu  Antarctic record  43-  (1)  162  -210  1999/03  [Not refereed][Not invited]
     
    南極ドームふじ観測拠点において, 1993年パイロット孔の掘削とケーシングが行われたのに引き続き, 1995年から2カ年にわたり本格的な深層コア掘削が進められ, 1996年12月に2503.52m深に達した。本掘削におけるコア掘削の総回数は1369回, チップ回収作業は837回に及んだ。1回の平均コア掘削長は1.75m, 一日の平均コア掘削長は8.21mであった。本報告では, 現地で使用された掘削システムの概要とともに, 掘削の経過, および掘削の方法を述べるとともに, 掘削中に生じたさまざまなトラブルについても取られたその対策とともに報告し, 併せて今後の課題を示した。Deep ice coring was carried out at Dome Fuji Station, Antarctica in 1995 and 1996 following a pilot borehole drilled and cased with FRP pipes in 1993,and reached 2503.52m in December 1996. Total numbers of ice coring runs below the pilot borehole and chip collection were 1369 and 837 respectively. The mean coring depths per run and per day were 1.75m and 8.21m respectively. We report the outline of the coring operation, the system, coring method, and troubles encountered during the coring work.
  • SHIRAIWA T.  Cryospheric Studies in Kamchatka (]G0002[)  8  -19  1999  [Not refereed][Not invited]
  • Takayuki SHIRAIWA, Fumihiko NISHIO, Takao KAMEDA, Akiyoshi TAKAHASHI, Yoko TOYAMA, Yaroslav D. MURAVYEV, Alexander A. OVSYANNIKOV  Seppyo  61-  (1)  25  -40  1999  [Not refereed][Not invited]
  • T Watanabe, L Dali, T Shiraiwa  GEOMORPHOLOGY  26-  (1-3)  185  -197  1998/12  [Not refereed][Not invited]
     
    The onset and termination of the formation of debris cones and the rate of denudation of source areas were studied in the Langtang Valley, central Nepal Himalaya. A stereo photogrammetric analysis was employed to map a detailed topography of debris cones, through which the volume of 19 cones was calculated. Debris cones were classified into four types (types 1-4) based on the criteria, such as incision of a toe, sizes of a cone and surface boulders, altitudinal distributions and vegetation cover. Cones of types 1-3 had been formed after deglaciation following the Langtang stage (3310 years BP). Type 1 cones are characterized by incision of toes by glaciers of the Lirung and Yala stages. The formation of the type 1 cones terminated well before 2000 years BP, Radiocarbon dates of charcoal fragments and buried soils show the major period of formation of the type 2 cones from 3300 to 2000 years BP. The rate of sedimentation calculated near the toe of cone 3 has been reduced in the last 5 centuries from 30.0 cm/100 years to 5.5 cm/100 years. The large amount of denudation of source areas (116.9-132.5 m) indicates that slope failures initiated the formation of type 3 cones. The development of type 4 cones made less of a contribution to landscape evolution in the valley. The rates of denudation for source areas were calculated except for those above type 3 cones. The average rates are 15.6-6.2 mm/year (above type 1 cones), 3.2 mm/year (type 2 cones) and 3.4 mm/year (type 4 cones). Debris cones of types 2 and 3 are located on the valley floors which are completely deglaciated. Those of types 1 and 4, on the other hand, are located by the large valley glaciers with debris cover. The formation of type 1 cones is important especially in terms of debris supply to moraines and supra-glacial debris in the upper valley. (C) 1998 Elsevier Science B.V. All rights reserved.
  • Matsumoto Takane, Kodama Yuji, Shiraiwa Takayuki, Yamaguchi Satoru, Sone Toshio, Nishimura Kouichi, Muravyev Yaroslav D., Khomentovsky Peter A., Yamagata Kotaro  Low temperature science. Ser. A, Physical sciences. Data report  56-  53  -68  1998/03  
    In order to understand climatic features of alpine environment and to evaluate east-west climateic contrast in Kamchatka Peninsula, Automatic Weather Stations (AWS) were installed on three alpine regions : Koryto Glacier, Ushkovsky Volcano and Mt. Kozyrevka. Meteorological data were measured and recorded automatically from July, 1996 to September, 1997. The data taken by AWS observations are reported.
  • 山口悟, 白岩孝行, 成瀬廉二  雪氷  60-  (4)  279  -287  1998  [Not refereed][Not invited]
  • Distribution and short-term Variations of flow velocities at Koryoto Glacier in the Kronotsky Peninsula, Kamchatka, Russia
    Bulletin of Glacier Research  16-  51  -56  1998  [Not refereed][Not invited]
  • ENOMOTO H. H.  Journal of Geophysical Research  103-  (D18)  23103  -23111  1998  [Not refereed][Not invited]
  • Automatic weather station program during Dome Fuji Project by JARE in east Droning Maud Land, Antarctica (jointly authored)
    Annals of Glaciology  (27)  528  -534  1998  [Not refereed][Not invited]
  • T Shiraiwa, YD Muravyev, S Yamaguchi  ARCTIC AND ALPINE RESEARCH  29-  (4)  414  -421  1997/11  [Not refereed][Not invited]
     
    Field observations were conducted at the summit ice cap of the Ushkovsky volcano, central Kamchatka, in the summer of 1996, in order to evaluate the potential of the ice cap for reconstruction of the past climate over Kamchatka. A 27-m-long firn-core contains an approximate 27-yr record of net balance with an average accumulation rate of 0.57 m a(-1) water equivalent. The temperature of the firn is -16.5 degrees C at 10-m depth. Average annual accumulation rates are calculated by reference to dated ash layers and amount to between 0.38 and 0.88 m a(-1) during six fixed periods. Depth and age of pore close-off are calculated as 58 m and 66 yr at this site by empirical formulas. Comparisons of the accumulation rates with winter precipitation at lowland stations indicate that there is a positive relationship with winter precipitation on the eastern and western coasts of the peninsula. We cannot find a clear relation between the rates and annual average sea-ice extent in the Sea of Okhotsk. which implies the vapor source to the ice cap could have been the North Pacific. Melt feature percentage in the firn core displays a clear positive relationship with summer air temperature at 700 hPa ever Kamchatka. The result obtained suggests that the ice cap has potential for the reconstruction of paleoclimate over the Kamchatka Peninsula.
  • YAMAGUCHI Satoru, SHIRAIWA Takayuki, MURAVYEV Yaroslav D., GLAZIRIN Gleb E., NARUSE Renji  Bulletin of Glacier Research  15-  47  -52  1997/07/01
  • KODAMA Yuji, MATSUMOT Takane, GLAZIRIN Gleb E., MURAVYEV Yaroslav D., SHIRAIWA Takayuki, YAMAGUCHI Satoru  Bulletin of Glacier Research  15-  37  -45  1997/07/01
  • Kodama Yuji, Shiraiwa Takayuki, Kobayashi Daiji, Matsumoto Takane, Yamaguchi Satoru, Muravyev Yaroslav D., Glazirin Gleb E.  Low temperature science. Ser. A, Physical sciences. Data report  55-  107  -136  1997/03  
    In order to better understand the response of the glaciers in Kamchatka to a global climatic change, meteorological, hydrological and glaciological observations were carried out at Koryto Glacier in the Kronotsky Peninsula in July, 1996. We also made a preliminary shallow firn coring at an ice cap on the top of Ushkovsky Volcano, Kamchatka for the reconstruction of past climate over the region from July to August, 1996. The data taken in this expedition were reported.
  • 東信彦, 亀田貴雄, 高橋修平, 白岩孝行, 渡辺興亜, 藤井理行, 上田豊, 金森悟, 斉藤隆志  日本雪氷学会全国大会講演予稿集  1997-  1997
  • 白岩孝行  氷河  1997
  • 松岡健一, 白岩孝行, 浦塚清峰, 大井正行, 前野英生, 山口悟, MURAVYEV Y D, 成瀬廉二, 前晋爾  雪氷  59-  (4)  257  -262  1997  [Not refereed][Not invited]
  • Glaciological features of Koryto Glacier in the kronotsky Peninsula, Kamchatka, Russia
    Bulletin of Glacier Research  15-  27  -36  1997  [Not refereed][Not invited]
  • SHOJI Hitoshi, SAITO Takashi, SAITO Takeshi, SHIRAIWA Takayuki, TAGUCHI Yuji, YOKOYAMA Kotaro, HONDOH Takeo, WATANABE Okitsugu, MOTOYAMA Hideaki, FURUKAWA Teruo, TAKEKAWA Motoaki, AGETA Yutaka  Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology  10-  149  -149  1996/09  
    Information on paleoenvironmental changes on the earth is preserved in the form of physical and chemical stratigraphic features in large polar ice sheets. Extraction of ice core signals makes it possible to evaluate and reconstruct past global variations of climate and stmospheric circulation. A deep ice coring and analysis effort was started at Dome Fuji Station (77°19′01″S, 39°42′12″E). Antarctica by the 32nd Japanese Antarctic Research Expedition (JARE-32) in 1991 and will be completed with continuous deep core retrieval in 1997. JARE-32,-33 and -34 parties set up a traverse route from Syowa Station to Dome Fuji Station, selected the coring site considering the results from radar soundings and GPS positions, and conducted shallow ice coring to a depth of 112.6m at the site. JARE-35 party completed construction of a camping/drilling facility for JARE-36 and -37 wintering parties to perform deep ice coring through the ice sheet with a thickness of approximately 3km. JARE-36 parties also conducted glaciological, meteorological and medical observations during the periods of cargo transportation and camp-construction activities both along the traverse route and at the Dome Fuji Station drilling site.
  • ENOMOTO Hiroyuki, MOTOYAMA Hideaki, SHIRAIWA Takayuki, SAITO Takashi, KAMEDA Takao, FURUKAWA Teruo, TAKAHASHI Shuhei, WATANABE Okitsugu  Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology  10-  155  -155  1996/09  
    Automatic weather stations (AWS) using data loggers were distributed along the traverse route from Syowa Station to Dome Fuji Station (3810m a. s. l.). A data logger was set at Dome Fuji Station in January, 1994 and the first year-round observations were performed at Dome Fuji Station. The temperature data shows recurring abrupt increases in winter. The minimum temperature in 1994 was -78.1℃ and the mean temperature was -52℃. Wind direction was highly variable. Katabatic wind with constant wind direction is not observed but wind direction rotated counter-clockwise throughout the year. There were some interruptions in the wind speed data, thus a complete wind speed data set could not be obtained at Dome Fuji Station. However, the data show a wind of 12.7m/s in winter. The wind direction in that case was between north and east. This could be a case of a storm at Dome Fuji Station.
  • SHIRAIWA Takayuki, TAGUCHI Yuji, SAITO Takashi, SHOJI Hitoshi, YOKOYAMA Kotaro, WATANABE Okitsugu, ENOMOTO Hiroyuki, KODAMA Yuji, TAKEUCHI Yukari  Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology  10-  150  -150  1996/09  
    Observations on the evaporation-condensation process and heat-balance were conducted at Dome Fuji Station, the highest point of Queen Maud Land, East Antarctica, during the austral summer of 1994/1995. Evaporation and condensation at the snow surface were measured by weighing evaporation-pans filled with undisturbed snow twice a day; 0600 a. m. and 1800 p. m. Heat fluxes of net radiation (〓_n) and in the snow (〓_c) were measured by a net radiometer and a series of thermistor sensors installed in the snow, respectively. The evaporation amounted, at its maximum, to approximately (10)^<-1>kg m^<-2> from 0600 a. m. to 1800 p. m., while the condensation was 2×(10)^<-2>kg m^<-2> during the night from 1800 p. m. to 0600 a. m. As a result, evaporation dominated condensation during the two summer months of 1994/1995 at Dome Fuji Station. If we calculate the latent heat flux (〓_l) on the basis of observations of the evaporation and condensation, and the residue of heat flux components is assigned to the sensible heat flux (〓_s), the average amounts of each component during the two summer months were calculated to be 12 W m^<-2>(〓_n), -4 W m^<-2>(〓_c), -1 W m^<-2>(〓_l), -7 W m^<-2>(〓_s).
  • Shiraiwa Takayuki, Saito Takashi, Saito Takeshi, Shoji Hitoshi, Taguchi Yuji, Abo Toshihiro, Yamamoto Yuji, Inagawa Yuzuru, Yokoyama Kotaro, Watanabe Okitsugu  JARE data reports  211-  1  -69  1996/03
  • Takayuki SHIRAIWA, Takashi SAITO, Takeshi SAITO, Hitoshi SHOJI, Yuji TAGUCHI, Toshihiro ABO, Yoshikatsu YAMAMOTO, Yuzuru INAGAWA, Kotaro YOKOYAMA, Okitsugu WATANABE  JARE data reports. Glaciology = JARE data reports. Glaciology  25-  2  -4  1996/03
  • Takayuki SHIRAIWA, Takashi SAITO, Takeshi SAITO, Hitoshi SHOJI, Yuji TAGUCHI, Toshihiro ABO, Yoshikatsu YAMAMOTO, Yuzuru INAGAWA, Kotaro YOKOYAMA, Okitsugu WATANABE  JARE data reports. Glaciology = JARE data reports. Glaciology  25-  5  -30  1996/03
  • 瀬古勝基, 上田豊, 飯田肇, 白岩孝行, 幸島司郎  日本雪氷学会全国大会講演予稿集  1996-  1996
  • 亀田貴雄, 東信彦, 榎本浩之, 古川晶雄, 田中洋一, 竹川元章, 白岩孝行, 上田豊, 渡辺興亜  日本雪氷学会全国大会講演予稿集  1996-  1996
  • 白岩 孝行  地学雑誌  105-  (2)  Plate1  -Plate2  1996
  • ENOMOTO Hiroyuki, WARASHINA Hideo, SAITO Takashi, SHIRAIWA Takayuki  Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology  10-  119  -126  1996  [Not refereed][Not invited]
     
    This paper focuses on the interannual variability of sea-ice conditions in spring and summer in the vicinity of Syowa Station. Sea ice extent and concentration are discussed using DMSP SSM/I satellite passive microwave data. Persistent high ice concentration was observed in December in 1989 and 1993. In those years, sea ice was formed earlier in the autumn (April-May) and expanded rapidly in this initial stage. The sea ice concentrations were higher throughout the winter season in these years. Cold and calm weather conditions in autumn seem to be important in determining the following winter ice condition.
  • SHIRAIWA Takayuki, SHOJI Hitoshi, SAITO Takashi, YOKOYAMA Kotaro, WATANABE Okitsugu  Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology  10-  1  -12  1996  [Not refereed][Not invited]
     
    Stratigraphical observations were carried out on the surface snow from the coast to the ice divide, Dome Fuji Station, in the summer of 1994/1995,to provide microwave remote sensing with ground truth data. Stratification, grain size and dielectric properties were measured in 1m-deep snow pits excavated every 30-40km of the 1000km-long Dome Fuji Station traverse route. There exist three regional characteristics in the altitudinal distribution of the averaged real part of the dielectric constant ε′ : a constant value in the coastal region, a higher value in the intermediate region, and a gradual decrease in the higher region. According to the measured snow properties indispensable to the utilization of microwave remote sensing, the dry snow zone of the studied area is divided into three parts : a region of compacted snow and solid-type depth hoar (1000 to 2000/2300m a.s.l.), where spatial and vertical distribution of various snow properties are uniform; a region of wind-packed snow and skeleton-type depth hoar (2000/2300 to 3500m), which is characterized by spatial alteration of the glazed surface and the stratified depth hoar layer; a region of interbedded skeleton-and solid-types depth hoar (higher than 3500m) where the seasonal stratification of snow is characterized by thin-hard summer and thick-soft winter layers.
  • 成瀬廉二, 秋田谷英次, 西村浩一, 白岩孝行, 山口悟, 須沢啓一, 天見正和, 伊藤陽一, 根本征樹  低温科学 資料編  55-  (55)  13  -26  1996  [Not refereed][Not invited]
     
    Snow surveys were made at 58 points in Hokkaido at the end of February 1996. Items of measurement were thickness of snow cover, water equivalent of snow, snow stratigraphy, grain sharpe, grain size, Ram hardness and snow temperature. In the winter 1995-96, snow accumulation was significantly large in and around Sapporo, whereas it was relatively small in the eastern Hokkaido. Mean density and mean Ram hardness of snow covers showed high values in the western part and low values in the eastern part of Hokkaido where the depth hoar was dominant.
  • 秋田谷英次, 西村浩一, 白岩孝行, 尾関俊浩, 伊藤陽一, 山口悟, 須沢啓一  低温科学 資料編  55-  (55)  1  -11  1996  [Not refereed][Not invited]
     
    Snow pit data are shown for the winter of 1995-96 in Sapporo. Data on snow stratigraphy, snow type, density, hardness, water content, snow temperature, water equivalent and Ram hardness were collected in a snow pit on the 5th, 15th, 25th day of every month duriing the winter. Characteristics of snow cover and snow depth for the last 14 years in Sapporo are also shown. Maximum depth of snow cover in this winter was 144cm observed on 11th of February, it was the largest record during the last 14 years. The snow melted away on 21st April, which is the lastest record during the same period.
  • YAMADA Tomomi, SHIRAIWA Takayuki  Journal of the Japanese Association of Snow and Ice  57-  (3)  257  -267  1995  [Not refereed][Not invited]
     
    ヒマラヤ・カラコルム地域の近年の氷河変動を,前世紀~1970年代までの観察・観測記録および最近20年間の観測結果の2つの観点からまとめた.ヒマラヤ・カラコルム地域とも,前世紀以降,大局的には後退傾向が顕著であるが,カラコルム地球では20世紀初頭に氷河の前進が認められた.また,カラコルム地域ではサージによる氷河の突発前進が頻繁に生じていることがわかった.最近の20年間に関しては後退傾向が著しく,特に後半になって後退傾向はより顕著になっている.ネパール・ヒマラヤの観測からは,ここ数年の氷河の著しい後退の原因は気温上昇にあると推定される.前世紀以降の氷河変動の原因に関しては,気温や降水量の変動,あるいは氷河の力学的な応答の遅れなどが指摘されているが,まだ明らかなことはわかっていない.
  • Hideaki Motoyama, Hiroyuki Enomoto, Teruo Furukawa, Kokichi Kamiyama, Hitoshi Shoji, Takayuki Shiraiwa, Kazuo Watanabe, Kunihisa Namasu, Hisataka Ikeda  Antarctic Record  39-  (2)  94  -98  1995  [Not refereed][Not invited]
     
    GPS相対測位による東南極のS16からドームふじに至るトラバースルートに沿っての氷河流動観測が1992年から行われている。このGPS衛星を利用しての相対測位法は, 従来の衛星を用いたJMR法や三角鎖法より野外では簡便な観測法である。観測誤差は, 2地点間の距離の100万分の1以内に収まる。同一地点の1年平均の氷河の流動速度と方向は安定していた。Ice flow has been observed along traverse routes from S16 to Dome Fuji, East Antarctica using the differential GPS (Global Positioning System) method since 1992. This positioning method is easier to use in the field than the satellite doppler positioning system (JMR) or triangle chain method. The vertical and horizontal error of positioning was within 1ppm of base line. The horizontal speed and direction of ice flow were almost the same both years at each site.
  • Tomomi YAMADA, Takayuki SHIRAIWA  Seppyo  57-  (3)  257  -267  1995  [Not refereed][Not invited]
     
    ヒマラヤ・カラコルム地域の近年の氷河変動を,前世紀~1970年代までの観察・観測記録および最近20年間の観測結果の2つの観点からまとめた.ヒマラヤ・カラコルム地域とも,前世紀以降,大局的には後退傾向が顕著であるが,カラコルム地球では20世紀初頭に氷河の前進が認められた.また,カラコルム地域ではサージによる氷河の突発前進が頻繁に生じていることがわかった.最近の20年間に関しては後退傾向が著しく,特に後半になって後退傾向はより顕著になっている.ネパール・ヒマラヤの観測からは,ここ数年の氷河の著しい後退の原因は気温上昇にあると推定される.前世紀以降の氷河変動の原因に関しては,気温や降水量の変動,あるいは氷河の力学的な応答の遅れなどが指摘されているが,まだ明らかなことはわかっていない.
  • Akitaya Eizi, Shiraiwa Takayuki  Low temperature science. Ser. A, Physical sciences. Data report  51-  1  -8  1993/03  
    Snow pit data are shown of the winter of 1991-92 in Sapporo. Snow stratigraphy, snow type, density, hardness, water content, snow temperature, water equivalent and Ram hardness were observed using a snow pit on the 5th, 15th, 25th day of every month during the winter. Characteristics of snow cover and snow depth for the last 10 years in Sapporo are also shown.
  • Shiraiwa Takayuki  Low temperature science. Ser. A, Physical sciences. Data report  51-  59  -86  1993/03  
    Long-term measurements of rock surface temperatures were conducted at three sites in the Langtang Valley, Nepal Himalaya. Glacier Camp (5110m) and Kyangchen site (4110m) provided data for a south-facing slope, while Gangja La site (5090m) provided data for a north-facing slope. Frequest freeze-thaw cycles were observed at the Glacier Camp during all periods except for summer, at the Gangja La site during both spring and autumm, and at the Kyangchen site during winter.
  • 氷河地形に基づくヒマラヤ・チベットの古環境復元
    地形  14-  195  -220  1993  [Not refereed][Not invited]
  • SHIRAIWA Takayuki  Chikei  14-  (3)  195  -220  1993  [Not refereed][Not invited]
  • SHIRAIWA T.  Contributions from Institute of Low Temperature Science  38-  1  -98  1993  [Not refereed][Not invited]
  • Akitaya Eizi, Shiraiwa Takayuki, Ozeki Toshihiro  Low temperature science. Ser. A, Physical sciences  50-  15  -21  1992/03
  • Akitaya Eizi, Shiraiwa Takayuki, Ozeki Toshihiro  Low temperature science. Ser. A, Physical sciences. Data report  50-  1  -8  1992/03
  • Fluctuation of the glaciers from the 1970s to 1989 in the Khumbu, Shorong and Langtang regions, Nepal himalayas.
    Bulletin of Glacier Research  10-  1992  [Not refereed][Not invited]
  • Timing of the Little Ice Age glaciation in Reindalen, West Spitsbergen, reconstructed by Lichenometry.
    Proceedings of the International Symposium on the Little Ice Age Clima.  1992  [Not refereed][Not invited]
  • A preliminary report on the air temperature in Reindalen, west Spitsbergen.
    Bulletin of Glacier Research  10-  1992  [Not refereed][Not invited]
  • Distribution of mass input on glaciers in the Langtang Valley, Nepal Himalayas.
    Bulletin of Glacier Research  10-  1992  [Not refereed][Not invited]
  • T SHIRAIWA, T WATANABE  ARCTIC AND ALPINE RESEARCH  23-  (4)  404  -416  1991/11  [Not refereed][Not invited]
     
    Glacial fluctuations in the Langtang Himal are discussed on the basis of multiple relative dating (RD) methods in addition to the C-14 method. The RD methods used for the classification of the moraine deposits include the Schmidt hammer rebound values, weathering rind thickness, percentage of clasts with oxidation stain, height of mineral projection, pit depth, percentage of weathered clasts, soil development, and soil color index. By using the RD data, we were able to divide the moraines into five stages (Gora Tabela, Langtang, Lirung, and Yala I and II); an older stage (Lama) is recognized only by the glacial-trough configuration extending down to an altitude of approximately 2600 m. The Gora Tabela Stage is defined by the deeply weathered Lower Till extending down to 3200 m a.s.l. The Langtang Stage (3650-3000 C-14 yr BP) probably corresponds to the greatest advance in the Holocene, followed by a series of smaller advances in the Lirung Stage (2800-550 C-14 yr BP), and the two smaller Little Ice Age advances (Yala I and II Stages).
  • 白岩孝行  地理  36-  (12)  71  -79  1991
  • Glacier Inventory of the Langtang Valley, Nepal Himalayas.
    50-  1991  [Not refereed][Not invited]
  • WATANABE T.  Bulletin of Glacier Research  7-  209  -220  1989  [Not refereed][Not invited]

Books etc

Presentations

  • Nishikawa Honami, Kobayashi Yusuke, Shiraiwa Takayuki
    Proceedings of the General Meeting of the Association of Japanese Geographers  2023  The Association of Japanese Geographers
     
    [背景] 知床半島は北海道北東部に位置し,その一部は2005年に世界自然遺産に登録された場所である.陸域だけでなく周辺海域も遺産地域に含まれている.知床は海・川・陸から成る豊かな生態系と高い生物多様性を有しており,これらの自然的特徴は世界的に価値の高いものである.しかし,沿岸域には数多くの海洋ごみが確認されており自然環境への影響が懸念されている. [目的] 海洋ごみ問題への対策が求められているが未だ知床沿岸の海洋ごみの実態は明らかではない.本研究では,漂着物のモニタリング調査を行うことで海岸に漂着しているごみ(漂着ごみ)の実態解明を目指した. [方法] 世界遺産内に位置するルシャ地区の海岸において, UAV (Unmanned Aerial Vehicle) を用いたSfM多視点ステレオ写真測量(Structure–from-Motion Multi-View Stereo Photogrammetry)及びタイムラプスカメラによる海岸の撮影を実施した. [結果] 海岸上の漂着ごみ及び流木から成る堆積物の位置を2020年から2022年の期間で比較すると,汀線側に位置する漂着物は波による浸食によってその前線が徐々に後退していた.タイムラプスカメラの画像から漂着物の変動は海氷が接岸する前の12月から1月にかけての冬期に起こっており,この時期に発生する高波の影響を強く受けていると考えられる.
  • Nishikawa Honami, Kobayashi Yusuke, Shiraiwa Takayuki
    Proceedings of the General Meeting of the Association of Japanese Geographers  2022  The Association of Japanese Geographers
     
    Ⅰ.はじめに 北海道の北東部に位置する知床半島は,海と陸を介する豊かな生態系や生物多様性が評価され2005年に世界自然遺産に登録された場所である.豊かな自然環境がある一方,遺産地域を含む半島沿岸部には多くの海ごみが漂着する.半島西側に位置するルシャ地区の海岸はごみの漂着量が多い地域の一つであり,ごみと流木が海岸線に沿って大量に堆積している.地元自治体やボランティアによる海岸清掃が年1回程度行われているが未だ多くのごみが残置されたままである.効果的な海岸清掃には現存するごみの動態を明らかにすることが重要だが,この地域での漂着ごみの研究は限られ,特にその季節変化や漂着・流出機構は未解明の課題である.そこで,海岸観測から漂着ごみの特性及びごみの漂着・流出過程の解明を本研究の目的とした. Ⅱ.研究方法 海岸に調査区画(10 m×30 m)を二つ設置して区画内のごみを収集後,8種類(プラスチック,布,発泡スチロール,ゴム,金属,ガラス・陶磁器,紙,その他人工物)に分類し,それぞれの個数と重量を計測した.また,ごみを産業廃棄物と一般廃棄物とに分けて同様に個数と重量を計測した.本研究では,流木や礫に埋まっているごみは対象とせず,表面上の目視可能なごみを収集対象とした.海岸の地形変化を調べるためにRTK-GNSS搭載のUAV(Phantom4 RTK, DJI)を用いて写真測量を行った.SfM-MVS解析によって空撮画像から海岸の3Dモデルを作成し,2時期のDSMとオルソモザイク画からGISを用いて漂着ごみの堆積位置を比較した.更に,Time Lapse カメラを海岸に設置して,約1年間撮影を行った.撮影した映像からごみの漂着・流出時 期やその過程を調べた. Ⅲ.結果と考察 収集した漂着ごみを分類した結果,個数では全体の9割以上がプラスチックであった.重量でもプラスチックは全体の約8割~9割を占めていた.一般廃棄物の重量は二つの調査区画でそれぞれ14 kg ~ 40 kgであったのに対して,産業廃棄物の重量は170 kg ~ 735 kgあり重量差が大きかった.産業廃棄物は主に漁網やロープ等の漁業系廃棄物であった.2020年11月と2021年10月のオルソモザイク画像を比較した結果,海岸の一部で漂着ごみの堆積状態に変化が見られた.Time Lapseカメラの画像から,2020年12月中旬に海岸に打ち寄せた波によってごみの流出や陸側への移動が起こっていた.次に,堆積状態の変化が起こる時期を網走沖の波浪データを基に考察した.波高約4 m~5 m の波が高い日が数日続いた際に,海岸では堆積状態の変化が起こることが示唆された.このような波は隔年で発生しており,その度にごみの漂着量や位置が変化している可能性が高い.一方,波の影響をほとんど受けない陸側に堆積するごみは長期間同じ状態を維持していると考えられる.したがって,新たな漂着や流出が起こりづらい陸側のごみから回収していくことで海岸美化の促進が期待できる.
  • Sugita Yu, Kobayashi Yuusuke, Shiraiwa Takayuki
    Proceedings of the General Meeting of the Association of Japanese Geographers  2019  The Association of Japanese Geographers
     
    Marine litter was surveyed in the coast between Rusha and Pombetsu rivers, the Sea of Okhotsk coast of the Shiretoko Peninsula. Aerial photographs were taken by UAV and classification of the litter was conducted. A total of 1767 items was found, of which 87% was classified as plastic. Ridge composed of tangled up debris was seen uniformly at 20-30m away from the shoreline. Elevation map of the shore was made to estimate the volume of the ridge and the debris washed ashore.
  • Tsushima Akane, Matoba Sumito, Shiraiwa Takayuki
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2015  The Japanese Society of Snow and Ice / Japan Society for Snow Engineering
  • Ohata Yu, Toyota Takenobu, Shiraiwa Takayuki
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2015  The Japanese Society of Snow and Ice / Japan Society for Snow Engineering
  • OHATA YU, SHIRAIWA TAKAYUKI
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2013  The Japanese Society of Snow and Ice / Japan Society for Snow Engineering
  • Shiraiwa Takayuki
    Proceedings of the General Meeting of the Association of Japanese Geographers  2012  The Association of Japanese Geographers
     
    It was found that the Amur River basin could be considered as a giant "fish-breeding forest" for the Sea of Okhotsk and Oyashio openwater by suppling dissolved iron. It is an essential element for the photosynthesis of phytoplankton and the sufficient supply of dissolved iron makes the Sea of Okhotsk and Oyashio openwater as one of the world richest oceans. 
  • 火星の北極冠に見られるスパイラルトラフの形成過程についての実験的研究:予報
    清水裕貴, 横川美和, 内藤健介, 泉典洋, 山田朋人, GREVE Ralf, 白岩孝行
    日本堆積学会大会プログラム・講演要旨  2011
  • Matoba Sumito, Sasaki Hirotaka, Shiraiwa Takayuki
    Abstracts of Annual Meeting of the Geochemical Society of Japan  2011  GEOCHEMICAL SOCIETY OF JAPAN
     
    近年行われた海洋への鉄散布実験の結果、北部北太平洋域の東西両海域において、鉄は一次生産の制限要因として重要であることが明らかになった。鉄の供給源については、下層からの鉛直的な供給と春先の黄砂の飛来によって大気を通してもたらさせる鉄フラックスの寄与が大きいと考えられているが、その寄与率について定量的な議論が十分なされていない。本研究では、アラスカの山岳氷河アイスコアから大気由来鉄の沈着量の経年変化を推定し、雪氷試料を用いた実験から黄砂から降水中に溶解する鉄量を求め、大気中の黄砂が海洋に湿性沈着したときに短期間で海洋環境に与えるインパクトを評価した。その結果、アイスコアから推定した鉄の年間沈着量は1993から2003年の平均で9.3 mg/m2 yrだった。アイスコアおよび札幌の積雪中に含まれる鉄の溶解度はそれぞれ10%,1.2%だった。
  • Shiraiwa Takayuki
    Proceedings of the General Meeting of the Association of Japanese Geographers  2009  The Association of Japanese Geographers
     
    The Amur River basin was found to play a key role in supporting primary production in the Oyashio region of the western subarctic Pacific Ocean by supplying dissolved iron which was essential element for phytoplankton growth. Because the dissolved iron mainly forms as a complex of iron and fuluvic acids originating from forests and swamps in the Amur River basin, it is likely that land-cover changes in the Amur River basin may affect primary production in the Sea of Okhotsk and the Oyashio region. The land-ocean linkage mention above reminds us of the Japanese concept of Uotsuki-rin (the fish-breeding forest). However, the Amur-Okhotsk-Oyashio linkage is much stronger than that in the conventional concept. More importantly, this is the first attempt to relate the continental-scale terrestrial environment with open waters. Therefore, we refer to the idea as "Kyodai" Uotsuki-rin kasetsu (the "Giant" Fish-Breeding Forest (GFBF) Hypothesis). We have conducted various kinds of scientific researches to verify the hypothesis since 2005 and we considers it was nearly done at present. The GFBF is also recognized as a natural system that transport various nutrients, trace elements like dissolved iron, and pollutants from an upper area (i.e., the Amur River basin) to a lower area (the Sea of Okhotsk and Oyashio region). Fluxes of such materials can fluctuate significantly owing to various human activities including agriculture, forestry and industry. The human activities are then influenced by both local and international sociological, political and economic situations with which the lower stakeholders are closely related. Therefore, it is also possible to recognize the GFBF as a social system connecting various stakeholders beyond the national boundaries by cycling materials, information and properties. In spite of its importance and uniqueness, there has been no framework for protecting/conserving the GFBF. This is mainly due to the geopolitical situation of the Amur River basin and the Sea of Okhotsk: the long-term political tensions in the area have hidden the environmental deterioration from the public. We would like to inform domestic and international communities of the GFBF and its importance. We will then propose an agenda for the conservation of the GFBF by collaborating with Russian and Chinese scientists by the end of fiscal year 2009.
  • Fukuda Takehiro, Sugiyama Shin, Shiraiwa Takayuki, Matoba Sumito
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2009  The Japanese Society of Snow and Ice / Japan Society for Snow Engineering
  • Matoba Sumito, Tsushima Akane, Sasaki Hirotaka, Muravyev Yaroslav D., Shiraiwa Takayuki
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2009  The Japanese Society of Snow and Ice / Japan Society for Snow Engineering
  • Hirotaka Sasaki, Matoba Sumito, Shiraiwa Takayuki
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2009  The Japanese Society of Snow and Ice / Japan Society for Snow Engineering
  • Sato Tatsuru, Shiraiwa Takayuki, Greve Ralf, Zwinger Thomas, Seddik Hakime
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2009  The Japanese Society of Snow and Ice / Japan Society for Snow Engineering
  • 安成 哲平, 白岩 孝行, 的場 澄人, 佐々木 央岳, 東 久美子
    大会講演予講集  2008  日本気象学会
  • Matoba Sumito, Ushakov Sergey V., Shimbori Kunio, Higuchi Kazuo, Sasaki Hirotaka, Yamasaki Tetsuhide, Ovshannikov Alexander A., Manevich Alexander G., Zhideleeva Tatyana M., Kutuzov Stanislav, Muravyev Yaroslav D., Shiraiwa Takayuki
    Preprints of the Annual Conference, Japanese Society of Snow and Ice  2007  THE JAPANESE SOCIETY OF SNOW AND ICE
  • Sasaki Hirotaka, Matoba Sumito, Shiraiwa Takayuki
    Preprints of the Annual Conference, Japanese Society of Snow and Ice  2007  THE JAPANESE SOCIETY OF SNOW AND ICE
  • KANAMORI Syosaku, SHIRAIWA Takayuki, MATOBA Sumito, YASUNARI Teppei
    Preprints of the Annual Conference, Japanese Society of Snow and Ice  2007  THE JAPANESE SOCIETY OF SNOW AND ICE
  • Matoba Sumito, Kanamori Syosaku, Benson Carl, Shiraiwa Takayuki
    Preprints of the Annual Conference, Japanese Society of Snow and Ice  2006  THE JAPANESE SOCIETY OF SNOW AND ICE
  • Toida Takeshi, Shiraiwa Takayuki, Matoba Sumito
    Preprints of the Annual Conference, Japanese Society of Snow and Ice  2006  THE JAPANESE SOCIETY OF SNOW AND ICE
  • 安成 哲平, 山崎 孝治, 白岩 孝行, 五十嵐 誠, Benson Carl S., 金森 晶作, 藤井 理行, 本堂 武夫
    大会講演予講集  2006  日本気象学会
  • Sato Tatsuru, Shiraiwa Takayuki, Matoba Sumito
    Preprints of the Annual Conference, Japanese Society of Snow and Ice  2006  THE JAPANESE SOCIETY OF SNOW AND ICE
  • 安成 哲平, 白岩 孝行, Benson Carl S, 山崎 孝治, 金森 晶作, 藤井 理行, 五十嵐 誠, 本堂 武夫
    大会講演予講集  2005/10  社団法人日本気象学会
  • 安成 哲平, 白岩 孝行, 金森 晶作, Benson Carl S, 山崎 孝治, 藤井 理行, 五十嵐 誠, 本堂 武夫
    大会講演予講集  2005/04  社団法人日本気象学会
  • 安成 哲平, 本堂 武夫, 白岩 孝行, Benson Carl S, 金森 晶作, 藤井 理行, 五十嵐 誠, 山崎 孝治, 青木 輝夫, 杉浦 幸之助
    大会講演予講集  2004/10  社団法人日本気象学会
  • Shrinkage of the permafrost in the Khumbu Himal, Nepal obsereved by the reiterated survey on the Nuptse Rock Glacier
    ASAHI Katsuhiko, WATANABE Teiji, SHIRAIWA Takayuki
    日本地理学会発表要旨集 = Proceedings of the General Meeting of the Association of Japanese Geographers  2004/09
  • Shiraiwa Takayuki, Takeuchi Nozomu, Azuma Kumiko
    Preprints of the Annual Conference, Japanese Society of Snow and Ice  2004  THE JAPANESE SOCIETY OF SNOW AND ICE
  • 山口悟, 成瀬廉二, 白岩孝行
    日本雪氷学会全国大会講演予稿集  2002/09
  • Recent glacier fluctuation in the Suntar Khayata Mountains, East Siberia
    SHIRAIWA T., YAMADA T., TAKAHASHI S., FUJII Y., KONONOV Y., ANANICHEVA M. D., KOREISHA M. M., MURAVYEV Y. D.
    日本地理学会発表要旨集 = Proceedings of the General Meeting of the Association of Japanese Geographers  2002/03
  • 山口悟, 成瀬廉二, 白岩孝行
    日本雪氷学会全国大会講演予稿集  2000/09
  • Paleoclimate reconstruction in the Circum Okhotsk Region by means of ice core analyses from Kamchatka Peninsula
    SHIRAIWA T., MATOBA S., NISHIO F., TOYAMA Y., KAMEDA T., TANAKA N., FUJIKAWA T., YAMAGATA K., MURAVYEV Y.d., SALAMATIN A.n.
    日本地理学会発表要旨集 = Proceedings of the General Meeting of the Association of Japanese Geographers  2000
  • 白岩孝行, MURAVYEV Y D, 松岡健一, SALAMATIN A N, 堀川信一郎, 山口悟, OVSYANNIKOV A A, 藤川哲弥, 田中教幸
    日本雪氷学会全国大会講演予稿集  1998/09
  • 高橋 修平, 榎本 浩之, 亀田 貴雄, 白岩 孝行, 児玉 裕二, 藤田 秀二, 本山 秀明, 渡邉 興亜, WEIDNER G. A, STEARNS C. R
    大会講演予講集  1997/10
  • 松岡健一, 白岩孝行, 浦塚清峰, 大井正行, 前野英生, 堀川信一郎, 山口悟, MURAVYEV Y, D, 前晋爾
    日本雪氷学会全国大会講演予稿集  1997/09
  • 白岩孝行, 山口悟, MURAVYEV Y D
    日本雪氷学会全国大会講演予稿集  1997/09
  • 山口悟, 白岩孝行, 成瀬廉二
    日本雪氷学会全国大会講演予稿集  1997/09
  • 白岩孝行, 山口悟, 児玉裕二, 松元高峰, MURAVYEV Y D, GLAZIRIN G E
    日本雪氷学会全国大会講演予稿集  1997/09
  • 山口悟, 白岩孝行, 成瀬廉二, MURAVYEV V D, GLAZIRIN G E
    日本雪氷学会全国大会講演予稿集  1997/09
  • SHIRAIWA Takayuki, YAMAGUCHI Satoru, MURAVYEV Yaroslav
    日本地理学会発表要旨集 = Proceedings of the General Meeting of the Association of Japanese Geographers  1997/03
  • 山口悟, 白岩孝行, 成瀬廉二
    日本雪氷学会全国大会講演予稿集  1996/09
  • 榎本 浩之, 本山 秀明, 白岩 孝行, 斉藤 隆志, 亀田 貴雄, 古川 晶雄, 高橋 修平, 渡辺 興亜
    大会講演予講集  1995/10

Association Memberships

  • 東京地学協会   日本雪氷学会   日本地理学会   

Research Projects

  • 日本学術振興会:科学研究費助成事業
    Date (from‐to) : 2021/04 -2024/03 
    Author : 三寺 史夫, 白岩 孝行, 植田 宏昭, 中村 知裕
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2017/04 -2020/03 
    Author : Mitsudera Humio
     
    Oyashio is one of most highly productive ocean in the world. This is owing to the Pan-Okhotsk land-ocean linkage system that provides the Oyashio with iron, an essential micronutrient, originating in wetlands in the Amur River basin via intermediate-layer circulation in the Sea of Okhotsk. This project aimed to elucidate roles of precipitation, snow and glacier over the Kamchatka Peninsula, which transfers information of atmospheric variations to the ocean through riverine discharge. We hypothesized that the riverine discharage from the peninsula may control the Pan-Okhotsk land-ocean linkage system. We have found that (1) the total amount of discharge from the Kamchatka Peninsula is approximately 80% of that of the Amur River, and (2) freshwater from the Kamchatka Peninsula gives more impacts on salinity of the dense shelf water that drives the intermediate-layer circulation than that from the Amur River does.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2015/04 -2018/03 
    Author : SHIRAIWA TAKAYUKI, TASHIRO Yuto, KUBO Takumi
     
    We investigated the Tyrma river basin of the Amur river from 2015 to 2017 in order to clarify possible cause of the rapid increase in dissolved iron of the Amur river in the late 1990s. Our 6-times field survey led to the findings of unique landscape called "mari" where sparse larch forest underlain by sphagnum vegetation. The "mari" is found to support sporadic permafrost and supplies significant amount of dissolved iron to its river. The "mari" is found to be developed in riparian zone of the river system by the analyses of indices like NDVI, NDWI and NDSI based on LANDSAT spectral data.
    We speculate the cause of rapid increase in dissolved iron concentration of the Amur river in the late 1990s were caused by melting of sporadic permafrost which resulted in the extension of redox condition in the upper part of the Amur river.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2012/04 -2015/03 
    Author : HANAMATSU YASUNORI, SHIRAIWA Takayuki, DA Zhigang, SIMONOV Eugine, KUBOTA Junpei
     
    Examining documents and materials concerning the implementation process of the Ramsar Convention such as the official documents drafted by the COPs of the Ramsar Convention and the Scientific and Technical Review Panel (STRP), it has been cleared that there is a general understanding for the ecological linkage between wetland adjacent to the coastal area and the marine coastal environment in the implementation process of the Ramsar Convention. However, on the other hand, it has hardly been discussed if there is both an ecological and institutional linkage between wetland located in inland basin area and marine environment, except for a problem of pollution from basin area to coastal or oceanic area. It can be considered that such a result has been largely reflected by the gap of knowledge or understanding between scientists studying wetland or inland basin and those studying oceanography, as well as the interpretive problem of the Ramsar Convention.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2010/04 -2014/03 
    Author : KOHSHIMA Shiro, USHIDA Kazunari, SHIRAIWA Takayuki, YOSHIMURA Yoshitaka, TAKEUCHI Nozomu, FUJITA Koji
     
    To estimate the response of glacier ecosystems to the global environmental change, we studied ecology of glacier microorganisms and albedo reducing process by microbial activities on the glaciers of various types by field studies at various part of the world. By comparing microbial flora, surface structure, albedo and environmental conditions on glaciers of various types, we could clarify relationship between glacial microbial flora and environmental condition, basic information needed to understand glacial microbial activities and how it affect glacier albedo.
  • カムチャッカ半島の氷河変動に関する研究
    科学研究費補助金
    Date (from‐to) : 1995 -2010
  • Glacier fluctuations in Kamchatka Peninsula
    Grant-in-Aid for Scientific Research
    Date (from‐to) : 1995 -2010
  • ヒマラヤ山脈の氷河変動に関する研究
    Date (from‐to) : 1987 -2010
  • Glacier fluctuations in Himalaya
    Date (from‐to) : 1987 -2010
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2007 -2009 
    Author : KOHSHIMA Shiro, USHIDA Kazunari, SHIRAIWA Takayuki, YOSHIMURA Yoshitaka, TAKEUCHI Nozomu, FUJITA Koji
     
    To understand how microbial activities on the glacier accelerate melting of the glaciers by reducing the surface albedo and estimate the intensity of such biological albedo-reducing effects, we conducted field researches on glacier albedo, microorganisms, surface structure and environmental conditions at various types of glaciers. We could clarify various regional differences in microbiological communities, albedo and environmental conditions on the glaciers that could provide important cues to understand the relationship between the microbial activity and the albedo of glaciers.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2007 -2009 
    Author : SHIRAIWA Takayuki, MATOBA Sumito, YAMATAGA Kotaro, SUGIYAMA Shin, IIZUKA Yoshinori, YOSHIKAWA Kenji, SASAKI Hirotaka, FUKUDA Takehiro, TSUSHIMA Akane
     
    In order to study the relationship between the North Pacific climate regime shift and ocean primary production, we analyzed iron concentrations in an ice core drilled at Aurora Peak, Alaskan Range. It was found that the averaged iron deposition was 8.8mg m^2yr^<-1> for the last 10 years, but it was 29 and 19mg m^2yr^<-1> for 2001 and 2002 when there were significant Kosa events. The results suggest that the atmospheric iron deposition to the upper 30-m mixed layer will not affect the biomass production in average but the amounts as recorded in 2001 and 2002 will be high enough to affect the ocean primary production.
  • 南極氷床の質量収支に関する研究
    Date (from‐to) : 1993 -2008
  • Glacier mass balance of the Antarctic Ice Sheet
    Date (from‐to) : 1993 -2008
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2004 -2007 
    Author : TAKAHASHI Shuhei, ENOMOTO Hiroyuki, KAMEDA Takao, SHIRASAWA Kunio, SHIRAIWA Takao, SUGIURA Konosuke
     
    In the period of IGY, Russian Academy has made glaciological researches extensively in Suntar-Khayata Range in Eastern Siberia, where about 180 glaciers were numbered. After the IGY, no observation was done in this area except aerial-photo or satellite observation. After 50 years, we made glaciological and meteorological observations as an activity of IPY. In 2004-2005, meteorological observation was done around Glacier No. 31 in Suntar-Khayata Range (the same place as the station before 50 years,) and at Oimiyakon area. The minimum temperature in a year was -59C at Oimiyakon (about 680m a. s.l.), while it was -45C at Glacier No. 31 (about 2050m a. s.l.), which suggests there was strong temperature-inversion in this area. In 2006-2007, meteorological observation was done between Magadan and Oimiyakon. The minimum temperature in 2007 was below -50C in inner region, -59.7C at Oimiyakon, while it was higher at coastal region, -23.2C at Magadan. Glaciers retreated 50-150m in length in the Northern massif from Little Ice Age to 1970's, and 100-200m in the Southern massif. This difference would derive from the difference of climate change between Sea of Okhotsk area and Arctic area.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2004 -2006 
    Author : KOHSHIMA Shiro, USHIDA Kazunari, SHIRAIWA Takayuki, YOSHIMURA Yoshitaka, TAKEUCHI Kozomu
     
    We improved the method of biological ice-core analysis applying the following new techniques of DNA analysis, such as species identification by 16SrRNA gene analysis, RT-PCR and microbial community analysis by DGGE method. These improvements enabled identification and quantification of bacteria and cyanobacteria in the ice-cores and snow and ice samples which had been difficult with old techniques. We collected ice-core samples in Russian Altai, European Alps, Chilean Andes, Alaska and analyzed biotic contents in these cores, such as snow algae, bacteria, fungi and pollens. In all these analyses, we could show that we can use the snow algae and pollens in the ice core as a good markers for annual layers useful for accurate dating of mid-latitude ice cores. We also examined bacterial DNA in the Antarctic ice cores for potential use as new environmental markers for the study on the past environment. We found that the Antarctic ice core preserved many ancient airborne bacteria and that bacterial community contained in the ice core differed between the samples of glacial age and interglacial age. The results suggest that air borne bacteria in the Antarctic ice cores could be new environmental markers if we can identify the source of the bacteria. So, we also started preliminary sampling and analysis of airborne bacteria released from Amazonian tropical rain forest, one of the possible source of bacteria stored in the Antarctic ice cores. To make comparative studies among glacier ecosystems of various part of the world, we collected microbiologial samples at the glaciers of the following regions: Russian Altai, Alaska mountain-range, European Alps, Chilean Andes and Rwenzori mountains of Uganda. By analyzing these samples with new methods, we could obtain many results important to understand glacier ecosystems and improve biological ice-core analysis. For example, we could find more than 10 new bacterial species adapted to cold environment in the snow and ice. The results of these analyses also showed that bacterial community on the glacier changed depending on the altitude. The result implies that we can use bacteria in the ice core as new environmental markers as well as snow algae because their their biomass and species composition change with environmental condition.[
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2002 -2006 
    Author : HONDOH Takeo, GREVE R・G, IIZUKA Yoshinori, FUJITA Shuji, HORI Akira, KAMEDA Takao
     
    The aim of the present study is to develop a new research field, Nanoglaciology, for better understanding the ice sheet processes on a macroscopic scale on the basis of various microphysical mechanisms involved in the processes, and to clarify the meaning of paleoclimate-and paleoenvironment-signals and their reliabilities. The main results obtained are summarized as ; 1. A mass transfer in the firn and the formation process of layer structures : We revealed structural changes of the layering formed at the surface with depth by the use of various experimental methods. Using SEM-EDS and micro-RAMAN, we found that most of the trace ions are included in the micro particles of sulfate salts and other salts. We proposed a new reaction diagram for determining the product materials in relation to ion balances. 2. Bubble to hydrate transition and gas fractionations : We found a new mechanism of hydrate nucleation that occurs on salt inclusions, and suggested that the layer structure in deeper part depends on a distribution of salt particles. 3. Development of crystal fabrics and ice sheet flow: We developed a new model taking anisotropy of fabrics into consideration that has been neglected so far. Applying this new model to DML Antarctica, we found much larger flow velocity than that calculated by an isotropic flow model. 4. Radar echo sounding of ice sheets : Using a new radar sounding system that was designed to detect internal structures of ice sheets, we found birefringence effect by the ice sheet for the first time. This new method enables us to deduce the internal fabric structures regarding to ice sheet flow.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2004 -2005 
    Author : SHIRAIWA Takayuki, NAKATSUKA Takeshi, TACHIBANA Yoshihiro, YAMAGATA Kotaro, MATOBA Sumito
     
    We analyzed the ice core drilled at Mt.Wrangell in 2004. The analyses were made for the upper 100m of the 217-m long ice core. They are hydrogen isotope ratio (0-50m), major ions (0-50m), dust concentration (0-80m), X-ray density (0-100m) and tritium (0-50m). Trace elements were also measured for the Mt.Logan ice core which we drilled in 2002. Following results are obtained by this research project : 1.Clear seasonal cycles are found for the upper 50m of the ice core in the cases of hydrogen isotope ratio, dust and tritium concentrations. The peaks appeared in summer for delta D and spring for the dust and tritium concentrations. 2.Standard deviation in the X-ray density variations are negatively related with delta D suggesting that the high density variations occur in spring-summer period when snow falls rather intermittently. 3.Concentration in dust becomes higher in spring and lower in the other periods. It is also found that the dust concentration has been increasing since 2000, which coincides with observation of dust falls in Japan. 4.Tritium concentration in the Wrangell ice core shows a beautiful seasonal cycle having the highest peak in spring. This is due to the so-called "Stratosphere-Troposphere Exchange" in air mass and the concentration can be a promising indication of atmospheric disturbances in spring. 5.Sodium flux is positively correlated with Pacific Decadal Oscillations suggesting the atmospheric-oceanic interaction in the North Pacific. 6.Annual Iron fluxes during the period 1980-2000 in the Logan ice core were varying from several μg/square m to 80μg/square m. The source of the iron can be ascribed to Asian dust and the nearby volcanoes. 7.Annual accumulation rates both in the Wrangell ice core and the Logan ice core showed clear negative relationship for the last 100 years, suggesting that the PDO has impacted mountain precipitation significantly.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2002 -2003 
    Author : YAMADA Tomomi, SAITO Mitsuyoshi, SHIRAIWA Takayuki, ISOGAI Koichi
     
    The inventory of present moraine dammed glacier lakes with the area more than 0.01km^2 in the northern and southern slopes of the Great Himalayas in the longitude between 85°15′ and 91°00′E, i.e., eastern Nepal, Sikkim, India, Bhutan and Tibet, China was made by using the latest Landsat ETM imageries taken in 2000, 2001 and 2002. Totally 539 lakes with the whole ares of 122.46km^2 are compiled in this area. The lakes were also compiled using Landast MSS imageries taken in 1976 and compared with the lakes found in the 2000-2002 imageries to clarify their temporal variations during 24-26 years. The results indicate that all lakes in 1976 expanded and many lakes are newly formed in the period. As a result of examining the causes of the development of the lakes in terms of the inclination of topography, where glaciers are situated, it is found that the gentler an inclination of topography is, the more the glacial lakes develop. The risk of a glacial lake outburst flood (GLOF) should he evaluated by lake size, the possibility of sudden huge mass input into the lake from the lake surroundings and the extent of a moraine-dam deterioration due to cored ice melting or piping. The measures of the risk assessment were studied by means of topographic interpretation such as mass movement landform and slope failure around the lake, using optical data of ASTER and Landsat and DEM stereoscopy constructed by SAR data pair. But the relationship between these information obtained by the analysis of satellite data sod the actual risk of GLOF should be continuously studied in future, because further collection of grand truth data is still necessary to GLOF risk assessment.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2001 -2003 
    Author : KOHSHIMA Shiro, TAKEUCHI Nozomu, SHIRAIWA Takayuki, USHIDA Kazunari
     
    Technical improvement of microbiological analysis of snow and ice : In order to identify bacteria growing in the snow and ice, we collected snow samples from Kuranosuke snow patch in Japan Alps, extracted 16s rRNA DNA from the samples and sequenced these DNA. We could identify bacterial species in the snow samples by matching the sequences with those in the various Databases. Samples of the the melting season contained a psychrophilic bacterium and two psychrotrophic bacteria. Seasonal change of bacterial biomass estimated by Real time PCR strongly suggested that these 3 species are growing in the snow during melt-season. We also succeeded in extraction and seaquencing of 18s rRNA DNA of snow algae and identification of some species. Biological ice core analyses using microorganisms in the snow and ice: We collected shallow ice cores and samples of microorganisms in the snow and ice of the glaciers of various part of the world, such as Alaska, Altai mountains, Chilean Andes and Bhutan Himalaya. Although analyses of the ice cores are still ongoing, all ice cores collected contained microorganisms such as snow algae and bacteria. These microorganisms in the ice cores were analyzed for potential use in ice core analyses. In some ice cores, it was revealed that microorganisms in the ice core, especially snow algae are effective marker of annual layers. We estimated incredibly high net accumulation rate of a Patagonian glacier (10-20m w.e.) by analyzing seasonal change of snow algal biomass in the ice core.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2001 -2003 
    Author : YAMADA Tomomi, NISHIMURA Koichi, FUSHIMI Hiroji, KOBAYASHI Shun'ichi, HIGAKI Daisuke, HARADA Koichiro
     
    Supra-glacial lakes have been formed on the debris covered ablation area of shrinking large valley glaciers in the southern and northern slopes of Great Himalayas in this half century, maybe due to the recent global warming. Since the lake was dammed by unstable moraines, a glacier lake outburst flood (GLOF) is frequently happened and a serious disaster is generated along down stream. The GLOF newly appears as the new face of natural disaster in the Himalayan countries. Once the lake was formed, its expansion is quite high rate. The lake is not simultaneously formed on all the glaciers : it is born on one glacier but not on the neighbor glacier, though they are situated under the same climatic and morphological condition. For predicting lake formation and its rapid growth, formation and expansion mechanism were studied. Underground water basin is formed in the ablation area of a valley glacier and bounded by impermeable moraine. After lowering surface arrives at the water table, stable ponds appear on the glacier surface expanding ponds connect each other and finally grow up to a lake. Surface lowering rate of the ablation area depends on surface mass balance and surface level change derived from glacier dynamics. The negative mass balance / the emergence velocity in the compressive pressure field, which are common at the ablation area, make the surface lowering / uplifting, respectively. Such a glacier that the surface debris is thinner, the altitude of the ablation area is lower and more numbers of pond and exposed ice beside it, which usually develop on the ablation area, have advantage for the surface lowering because of more negative surface mass balance. More gentle inclination of the ablation area, the less emergence velocity, i.e., less surface uplift. Those conditions are deferent from each glacier. A glacial lake is first created on such a particular glacier as the surface lowering rate is higher than the other glaciers even though they are in the same climatic condition. It is found that large expansion rate of the lake is attributed to the active calving of the ice cliff, which is formed in the glacier terminus and directly contact with the up-lake end Surface lake water warmed up by sun radiation is transported into the ice cliff by stable valley wind and melts the ice cliff under the water, effectively the cliff scooped out is collapsed and fall into the lake. This mechanism makes the lake expansion and the glacier rapidly retreat, efficiently. On the other hand, bottom ice under the lake melts away by lake water of 2〜3℃ and lake deepens. Investigation of heat budget of the lake proves that heat energy to melt floating ice, produced by calving, and bottom ice is mainly supplied by sun radiation absorbed in lake-surface with low albedo. Results of the study was already published in 3 English reports and 3 Japanese repots.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2001 -2002 
    Author : SHIRAKAWA Takayuki, TANAKA Noriyuki
     
    North Pacific DICE (Decadal and Interdecadal Climatic Event) was reconstructed from the analyses of 212 m-long ice core recovered at Ushkovsky Ice cap, Kamchatka, Russia. We developed analytical and numerical glacier-mechanical models in order to compensate the total strain so that we could reconstruct the 170-year time series of annual accumulation rates. Our spectral analysis showed that the acoumulation rates have spectra of 32.1, 12.2, 5.1 and 3.7 years. The time-series has clear negativc corrclation with so called PDO Index (Pacific Decadal Oscillations : Mantua et al., 1997). The results suggest that the accumulation rate changes in Kamchatka are strongly controlled by the atmospheric field covering the whole North Pacific Ocean.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2000 -2002 
    Author : NARUSE Renji, INAGAKI Masaharu, MAENO Hideo, TAKEI Iwao, FUJITA Shuji, SHIRAIWA Takayuki
     
    We have developed a novel ice-penetrating radar system that can be carried on a backpack. Including batteries for a three-hour continuous measurement, the total weight is 13 kg. In addition, it operates reliably down to -25°C, has a low power consumption of 24 W, and is semi-waterproof. The system has a built-in-one controller with a high-brightness display for reading data quickly, a receiver with 12-bit digitizing, and a 1-kV pulse transmitter with time variance of the pulse amplitude of less than 0.2%. The optical communications between components provides low-noise data acquisition and allows synchronizing of the pulse transmission with sampling. Measurements with this system successfully illustrate 300-m deep bed topography of Athabasca Glacier, Canada, in summers 2001 and 2002. To complement a technique to detect internal structures of seasonal snow-covers and glacier firn with ground-penetrating radar (GPR), we carried out calibration experiments and an observation of winter snow-cover (5.7 m thick dry snow with numerous ice layers) with an 800-MHz GPR. In particular, we aimed to discriminate periodic noise from radar echoes, which is inherent in GPR, and to obtain a relationship between the observed reflection strength and the magnitude of density contrasts. Experiments were made in the open space to evaluate noise levels and receiver characteristics of this system. Based on these, we removed noise from radar echoes in the snow-cover observation. We recognized numerous marked echoes in a noise-free radargram. Depths of these echoes coincided roughly with those of large density contrasts observed in the snow-pit. Thus, we argue that the echoes correspond to thin ice layers. Furthermore, the minimum density contrasts to be detected by this GPR are found to vary from about 100 to 250 kg m"3 with the depth from 1 to 6 m in the seasonal snow-cover.
  • 日本学術振興会:科学研究費助成事業
    Date (from‐to) : 2001 -2001 
    Author : 大畑 哲夫, 白岩 孝行, 成瀬 廉二, 榎本 浩之, 石井 吉之, 石川 信敬
     
    本研究の目的は、新たに計画されたWCRP(世界気候研究計画)のCliC(Climate and Cryosphere)の国際的な動きに対応し、今まで数多くの日本人研究グループが今までの蓄積をレビューし、「気候システムにおける雪氷の役割」についての総合的研究の具体的方針を示し、中国・ロシアなど諸外国との協力を含んだ研究課題・実施方法を立案することであった。 これを実行するために以下の3つの会合を開催した。 (1)会合名:CliC計画の内、氷河・氷床に関連した課題についての研究会 日時と場所:平成13年10月24日、北海道大学・低温科学研究所 参加者数:約20名 (2)会合名:CliC計画の内、積雪凍土に関連した課題についての研究会 日時と場所:平成13年11月27日、北海道大学・低温科学研究所 参加者数:約20名 (3)会合名:Asia CliC Meeting 日時と場所:平成14年2月25-27日、海洋科学技術センター横浜研究所 参加者数:約30名(海外はロシア2名、モンゴル2名、中国3名、ネパール1名、WCRP1名) (1)および(2)は若手を中心とした会合であり、各研究者が行ってきた今までの研究成果と今後の展望・方針について話をしてもらい、国内における研究の方向の潜在性を明らかにすることができた。また、(3)ではアジア地域の研究者とアジア地域で「雪氷圏と気候」について研究を行っている研究者を招聘し、研究の全体的動向と戦略および現在進行中の関連プロジェクトの話をしてもらった。これらの会合で議論された内容は基本的情報としてまとめられ、一つは来年度作成する国内の研究計画書に反映させる予定であり、また今後の検討によるが、アジア地域の共同研究書に反映させる予定である。
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 1999 -2001 
    Author : HARA Toshihiko, SONE Toshio, SHIRAIWA Takayuki, SUMIDA Akihiro, YAMAGATA Kotaro, HOMMA Kosuke
     
    We established several permanent plots of 1 ha for studying forest dynamics in Kamchatka. We carried out measurements of tree sizes (stem diameter, tree height), positions in the plots and physical environments such as light intensity and temperature. Picea seedlings established under the tree crown but not in gaps. Therefore, gap regeneration dynamics, which is a well known phenomenon in temperate and tropical forests, does not work in the forests of Kamchatka. This is a new phenomenon we found in Kamchatka. We hypothesize that this is because of severe environments such as high light stress, low temperature, low precipitation, in Kamchatka. We also carried out investigations in the Koryto glacier for reconstructing past climate change (temperature, precipitation) in Kamchatka for comparison with forest dynamics. We found that forest fire occurs more frequently in years with lower precipitation. Effects of forest fires on forest dynamics and climate change have also bee investigated by using simulation models.
  • 日本学術振興会:科学研究費助成事業
    Date (from‐to) : 2000 -2000 
    Author : 白岩 孝行
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 1999 -2000 
    Author : NARUSE Renji, SHIRAIWA Takayuki, SAWAGAKI Takanobu
     
    This study was conducted by analyzing mostly the samples and data obtained from the field surveys at glaciers in Patagonia, South America, made in 1999 and 2000. Ice-core drilling was carried out in December 1999 near the head(1756m a.s.l.)of the accumulation area of Tyndall Glacier. Analyses of stable oxygen and hydrogen isotopes as well as major ions and biomass along a 46-m-long ice-core were made in laboratories to estimate accumulation rates over the Patagonia Icefield. Annual net accumulation rate was estimated as 17.8m a^<-1> w.e.in the balance year of 1997/98-1998/99, whereas 11.0m a^<-1> in 1998/99-1999/00. This high net-accumulation rate ranks Tyndall Glacier as one of the more extreme maritime glaciers in the world. Almost all large-scale glaciers in Patagonia calve into fjords to the west and into lakes to the east. Dynamic behavior of the lacustrine calving Upsala Glacier was studied, and it was found that the frontal variations should be affected by the bed topography and longitudinal stretching of the glacier. A linear relationship between calving velocity and water depth near the calving terminus was derived from freshwater calving glaciers in Patagonia. Measurements of flow velocities and calving events were carried out in December 1999 near the terminus of Glaciar Perito Moreno. The largest velocity was obtained as 2.7m d^<-1> at the front tip. A dynamic glacier model was constructed on the basis of measurements of flow velocity and ablation rates at Soler Glacier and others.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 1998 -1999 
    Author : ANIYA Masamu, KOHSHIMA Shiro, KOBAYASHI Shunnichi, NARUSE Renji, SHIRAIWA Takayuki
     
    In 1998, the following results were obtained from field work in the Northern Patagonia Icefield. As for the study of the Holocene glacier variation of Soler Glacier, and Nef glacier in the valley of Soler River, the distribution and location of terminal moraines suggest the existence of the Younger Dryas advance (ca. 10,500 BP) and the Neoglaciation II (ca. 2000 BP) ; however, these suppositions awaits for confirmation by carbon 14 and cosmic ray datings. At Soler Glacier, glacier flow, the surface profile, strain rates were measured at the ablation area, along with hydrological and meteorological observations. Findings include that the amount of the basal slip accounts a large part of the glacier flow. The measurement of the surface profile revealed that the surface elevation decreased by 42 ± 5 m since 1986, with the mean annual thinning rate of 3.2 ± 5 m. Aerial photographic survey in 1998 of snouts of outlet glaciers of the Northern Patagonia Icefield revealed glacier variations since 1995 when it was done last time. All outlet glaciers but one (San Rafael Glacier) are found to have retreated during this period. Aerial photographic survey in 1999 disclosed a very interesting phenomenon. San Rafael Glacier, which was only glacier advancing since 1993, was found to have retreated between 1998 and 1999. From this observation, it is postulated that the unusual advance of San Rafael Glacier may no be attributed to the rainfall increase during the early 1970s as supposed before, but may be attributed to fjord topography and glacier dynamics. In November-December 1999, ice drilling was accomplished at the accumulation area of Tyndall Glacier of the Southern Patagonia Icefield, acquiring ice-core samples of 46 m long, along with in situ observation. Detailed chemical analyses of the ice-core will be done in the near future. At Perito Moreno Glacier, Calving activities were measured with photogrammetric measurements and the amount of calving was estimated by recording tidal waves caused by calving. Bathymetric survey of the lake was also done, revealing the depth near the glacier front down to 80 m deep. The depth of Brazo Upsala, into which Upsala Glacier is flowing, was measured, with the maximum depth close to 700 m. Bathymetric data are important to analyze the relationship between calving activities, glacier dynamics and glacier variations.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 1997 -1999 
    Author : SHIRAIWA Takayuki, TANAKA Noriyuki, KODAMA Yuji
     
    Reconstruction of the Aleutian low activity was attempted by means of physical and chemical analyses of ice cores recovered from Ushkovsky Ice Cap, Kamchatka, Russia. Major ions and stable oxygen and hydrogen isotopes were measured for the upper 60 m of the ice cores. We found that NaィイD1+ィエD1, KィイD1+ィエD1, MgィイD12+ィエD1, CaィイD12+ィエD1, ClィイD1-ィエD1, and SOィイD24ィエD2ィイD12-ィエD1 are definitely influenced by volcanic activities because high peaks in these ions were observed at the same horizons where visible ash layers are present. In contrast, variations in NOィイD23ィエD2ィイD1-ィエD1 seem to be independent from volcanic ashes except for major volcanic event The fluctuations found in NOィイD23ィエD2ィイD1-ィエD1 are quasi-synchronous to those observed in stable oxygen and hydrogen isotopes which are known to fluctuate seasonally. By counting seasonallity in NOィイD23ィエD2ィイD1-ィエD1 and stable isotopes, ice core was converted into time series of annual mass balances after compensation with densification and thinning by flow. We found a signiricant positive correlation between reconstructed mass balances and total annual precipitation recorded at foot slope of the Ushkovsky volcano for the last 70 years This implies that the ice core is the proxy of annual precipitation in this area and provide proxy precipitation record for the last 500 years once the whole record (212 m) will be analyzed in future. It will be also possible for this ice cores to show DICE events since the major climate shift observed around mid-1970s in North Pacific Ocean is clearly recorded in the reconstructed mass balances as increasing precipitation.
  • 日本学術振興会:科学研究費助成事業
    Date (from‐to) : 1996 -1998 
    Author : 小林 大二, OVSYANNIKOV A.A., MURAVYEV Y.D, 白岩 孝行, 亀田 貴雄, 西尾 文彦, 西村 浩一, 佐藤 利幸, 幸島 司郎, 山縣 耕太郎, OVSYANNIKOV エイ, KHOMENTOVSKY ピー, GLAZYRIN G., MURAVYEV Y., 曽根 敏雄, 兒玉 裕二
     
    カムチャツカ半島ウシュコフスキー氷冠において雪氷コア掘削ならびに現場解析を実施した。標高3,901m.氷厚240mを有するに地点に総計2.4トンの物資をヘリコプター輸送し,1998年6月20日から30日にかけて雪氷コアを掘削した.総掘削回数307回,総掘削時間103時間で全長211.7mの雪氷コアを採取した.掘削終了後,20m毎に掘削孔壁の温度を測定した.深度10mは-15.7℃,底部211.7mは-4.2℃であり,表面からほぼ直線的に漸増する温度垂直分布が得られた.掘削と並行して,層序観察,バルク密度測定,ECM(固体電気伝導度)測定,デジタルビデオによるコアの撮影を行った.現場解析ができた表面から深度141mまでのコアによれば,55m付近の氷化深度以浅では,コアは融解・再凍結氷と融解を経験していないフィルンからなり,氷化深度以深では融解・再凍結氷と圧密氷との互層から構成されていた.深度141mまでのコア中には目視できる火山灰だけでも183層が確認され,そのうち2層が火山灰の特徴から噴出年代が特定された.ECMとビデオ撮影したコアのモザイク画像とを比較した結果,ECMシグナルは火山灰層で低下,融解・再凍結氷層で上昇する傾向が見られた.一方,高所における掘削オペレーションであったため,人員の健康面での各種データを採取し,高所順応の個人差を考察した.
  • 日本学術振興会:科学研究費助成事業
    Date (from‐to) : 1996 -1996 
    Author : 白岩 孝行
     
    山地稜線の風下傾斜面における積雪分布について、吹き溜まり機構に着目して調査を行った。現地調査を実施したのは、北海道札幌市郊外の無意根山東斜面、北海道大雪山ヒサゴ多年性雪渓、およびロシア共和国カムチャッカ半島のカレイタ氷河涵養域の3地点である。無意根山では1997年3月中旬、ヒサゴ雪渓では1996年8月末、カレイタ氷河では1996年7月末に積雪調査を実施した。調査方法は、3地点ともに積雪量の空間分布を求めるため、浅層掘削を実施し、積雪量と稜線からの距離との関係を求めた。ヒサゴ雪渓とカレイタ氷河においては積雪分布に融雪の影響が含まれているが、融雪の空間分布は稜線からの距離に依存しないため、求められた積雪量分布は冬季の積雪量の分布と同様であると判断した。無意根山の観測は融雪開始前に実施したので、冬季の積雪量を直接表す。 ヒサゴ雪渓においては、稜線付近では強風によって堆雪が起こらないが、稜線から約250m離れた地点から吹き溜まりによる堆雪が始まり、500m付近まで漸次増加した。500mを過ぎた地点より急速に吹き溜まりの影響が減ずることが判明した。カレイタ氷河では、稜線付近で最も堆雪量が多く、稜線から離れるにつれ積雪が減少した。減少の傾きは1次直線でよく回帰できた。これより、この地点では吹き溜まりの影響がほとんど生じていないと考えられる。無意根山東斜面では稜線から離れるに従い、直線的に積雪が増加し、顕著な吹き溜まりの影響が観察された。 今回の研究では事例を収集するにとどまったが、今後は風速・地形・吹き溜まり量に関して定量的な関係を求める予定である。
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 1994 -1995 
    Author : KODAMA Yuji, SEKO Katsumoto, SHIRAIWA Takayuki, NISHIMUA Kouichi, ISHII Yoshiyuki
     
    Many snow patches have ice bdoy at the bottom. They are formed not only by the refreezing of percorated snowmelt water in the early spring, but also by the refreezing of meltwater stored over the ice body in late autumn. The chemical constituents in the firn and their amout are substantially affected by the snowmelt water. There are two types of snow patches distinguished by its formation. One is a snow drift type and another is a avalanch accumulated type. The avalanch accumulated type rarely has ice body at teh bottom due to the large thichness, which prevents cold wave penetration and therefore refreezing of meltwater stored inside the snow patch.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 1994 -1995 
    Author : AKITAYA Eizi, SHIRAIWA Takayuki, NARUSE Renji
     
    The road conditions in winter changed to slippery by the using of studless tire and antifreezing chemicals. A new classification on snow and ice on road was made by the observations during 1994 and 1995 winters. The slippery road conditions were classified into the following types ; bright-compacted snow, bright-ice layr and bright-ice film and these dangerous conditions were appeared under the high air temperature ; about 0゚C of maximum daily air temperature. Another dangerous road, bumpy ice developed frequently on the heavy traffic volume and thick compacted snow during melt at daytime and re-freeze at night time. The weak layrs causing a surface layr avalanche were investigated with field observations and 5 types of weak layr were confirmed at Hokkaido and Honshu. Two types of weak layr, depth hoar and surface hoar considered to be a main cause of big surface layr avalanches were investigated on the growing mechanism in the cold room and field in details. Lectures on avalanche mechanism and avalanche safety were carried out to mountain climbers and skiers. There was a heavy snowfall in 1995-96 winter at Sapporo metropolitan area, especially 9th January 1996, all buses in Sapporo city stopped by the heavy snow storm. All traffic facilities, roads, railways and airports, were confused again and again, in this winter. The damaged traffic facilities and the expense for snow remove were the highest record in history of Sapporo. The new road traffic management system will need for the heavy snowfall and snow storms. The new system must be decided under the agreements with administrator, user and resident taking one's responsibilities.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 1992 -1994 
    Author : NARUSE Renji, ANIYA Masamu
     
    We collected a number of remote sensing data which cover the Southern Patagonia Icefield (SPI : 350 km long and 50 km wide) in the southern Andes. The data include Landsat MSS (1976), TM (1986), Spot (1987,1991), and aerial photographs taken in 1945, the late 1960s and 1970s. Analyzing the data, variations since 1945 of eight major outlet glaciers in the SPI were elucidated. During the last 41 years, most glaciers showed a general recession, namely 2.2km at Jorge Montt, 13.4 km at O'Higgins and 2.6 km at Upsala glaciers. On the other hand, Bruggen Glacier advanced 5.3 or 8.4 km in the same period. Thus, it was found that, in Patagonia, some glaciers have behaved in different manners and with different magnitudes of variations. Also as a study of Geographical Information System, various features of glaciers were digitized, and inventories of 48 glaciers in the SPI were completed. With a mass-balance model which includes the calving rate, simulations of glacier variations were made for Upsala and Moreno glaciers. The result shows that a 100 m rise in the equilibrium-line altitude due to climatic change would result in a 200-350 m rise in the frontal altitude at Upsala Glacier corresponding to a retreat of 5-8 km, while it would cause only a 70-100 m rise at Moreno Glacier. Also numerical experiments using a degree-day method were made for Soler Glacier. As a result, a 20% decrease in snow-fall would result in only a 50m rise in the frontal altitude, while a 1^OC increase would result in a 100 m rise in the equilibrium-line altitude. Further experiments with a dynamical model are planned to carry out.
  • 日本学術振興会:科学研究費助成事業
    Date (from‐to) : 1993 -1993 
    Author : 白岩 孝行
     
    ネパールヒマラヤを代表する3つの地域(マルシャンディ川流域;ランタン地域;クンブ地域)について、1970年代と1990年代に撮影された斜め航空写真を収集し、同一の氷河について年代の異なる写真を比較することにより氷河の形態変化を調べた。1970年代の写真については名古屋大学大気水圏科学研究所所有のモノクロ画像を約250枚選択し、1990年代に撮影した約500枚のカラー画像とともに、イメージスキャナーを用いてコンピューターシステムに取り込み、光磁気ディスク上に保存してデータベースを作成した。 このデータベースを用いて各氷河の二期間(約20年)にわたる形態変化を調べたところ、以下のような知見が得られた。 1.標高6000〜5000m付近に位置する小型のクリーンタイブ氷河については、クンプ地域で顕著な後退傾向がみられた。 2.岩石に被覆された大型氷河については、マルシャンディ川流域のツランギ氷河、クンブ地域のトランバウ氷河、イムジャ氷河、ロウワ-バルン氷河などで末端部の後退およびこれに伴う末端部の氷河湖の拡大が生じていることが判明した。 3.小型氷河の形態変化については、変動のスケールが100m以下と小さいため、斜め空中写真による方法では、顕著な目じるしがあるなど好条件の場合を除き、検出が難しいという結論を得た。 以上の結果を総合すると、調査を行った地域では多くの氷河が後退傾向を示し、特に大型氷河では末端の後退に伴う氷河湖の拡大が進行するという興味深い事実が判明した。


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