研究者データベース

杉山 慎(スギヤマ シン)
低温科学研究所 雪氷新領域部門
教授

基本情報

通称等の別名

    SS004911

所属

  • 低温科学研究所 雪氷新領域部門

職名

  • 教授

学位

  • 博士(地球環境科学)(北海道大学)

ホームページURL

科研費研究者番号

  • 20421951

J-Global ID

プロフィール

  • パタゴニア、南極、グリーンランドなどを舞台に、氷河氷床に関する物理現象と変動メカニズムの解明に取り組んでいます。GPSや気象測器を用いた氷河上での観測の他、熱水掘削という技術を使って氷河底面での観測を進めています。教育面では、毎年スイスの氷河で大学院実習を実施するなど、次世代の極地研究者を育成する「国際南極大学」プロジェクトに従事しています。

研究キーワード

  • 北極   グリーンランド   パタゴニア   南極   氷床   氷河   雪氷学   Glaciology   

研究分野

  • 環境・農学 / 環境動態解析
  • 自然科学一般 / 大気水圏科学

職歴

  • 2017年04月 - 現在 北海道大学 低温科学研究所 教授
  • 2014年02月 - 2017年03月 北海道大学 低温科学研究所 准教授
  • 2005年10月 - 2014年01月 北海道大学 低温科学研究所 講師
  • 2003年04月 - 2005年09月 スイス連邦工科大学 研究員
  • 1997年09月 - 1999年12月 青年海外協力隊 ザンビア共和国 理数科教師
  • 1993年04月 - 1997年08月 信越化学工業 精密機能材料研究所 研究員

学歴

  • 2000年04月 - 2003年03月   北海道大学大学院   地球環境科学研究科
  • 1991年04月 - 1993年03月   大阪大学大学院   基礎工学研究科   物性物理工学科
  • 1987年04月 - 1991年03月   大阪大学   基礎工学部   物性物理工学科

所属学協会

  • 欧州地球科学会   国際雪氷学会   米国地球物理連合   日本雪氷学会   European Geosciences Union   International Glaciological Society   Japanese Society of Snow and IceInternational Glaciological SocietyAmerican Geophysical Union   

研究活動情報

論文

  • Shuntaro Hata, Shin Sugiyama, Kosuke Heki
    Communications Earth & Environment 3 1 2022年08月26日 [査読有り][通常論文]
     
    Abstract Glacial lakes are increasing in number and extent under a warming climate. Despite demand for lake monitoring and understanding outburst mechanisms, studies of large outburst events are sparse. Here we report an outburst of Lago Greve, a large proglacial lake in Chilean Patagonia. During the event in April–July 2020, the lake level dropped by 18.3 ± 1.2 m and the area decreased by 14.5 ± 0.02 km2. The total water discharge was 3.7 ± 0.2 km3, which is one of the largest glacial lake outbursts ever reported in satellite era. Satellite data indicated the collapse of a bump near the lake outlet triggered the event, by initiating erosion of the bank and bed of the outlet stream. Satellite gravimetry captured a signal of the event, although the magnitude of the corresponding mass change was inconsistent with the drained water mass. Our study demonstrated the potential for observing lake outburst using satellite imagery, altimetry, photogrammetry, and gravimetry.
  • Takahito Horikawa, Daiki Nomura, Naoya Kanna, Yasushi Fukamachi, Shin Sugiyama
    Frontiers in Marine Science 9 2022年07月22日 
    To understand the effects of the glacial meltwater supply on carbonate chemistry and the air–sea CO2 flux within the fjord, water samples were collected in Bowdoin Fjord in northwestern Greenland for dissolved inorganic carbon (DIC) concentration, total alkalinity (TA), oxygen isotopic ratio (δ18O), and chlorophyll a concentration analyses in the summers of 2016 and 2017. The partial pressure of CO2 (pCO2) in surface water, calculated from DIC and TA, was less than 200 µatm, and was significantly lower than that in the atmosphere (399 ± 3 µatm). Therefore, surface water of the fjord acts as sink for CO2 in the atmosphere (–4.9 ± 0.7 mmol m–2 d–1). To evaluate the effects of freshwater and land-derived substances by glacial meltwater on pCO2 in the fjord, we calculated the changes of pCO2 in salinity and carbonate chemistry that would result from the inflow of glacial meltwater into the fjord. The calculated pCO2 was high near the calving front, where the contribution of glacier meltwater was significant. Examination of the relationship between salinity-normalized DIC and TA, which was considered DIC and TA input from the land, suggested that the land-derived high pCO2 freshwater affected mainly by the remineralization of the organic matter by bacterial activity was supplied to the Bowdoin Fjord.
  • Shungo Fukumoto, Shin Sugiyama, Shuntaro Hata, Jun Saito, Takayuki Shiraiwa, Humio Mitsudera
    Journal of Glaciology 1 - 14 2022年07月04日 [査読有り]
     
    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.
  • L. G. Evers, P. S. M. Smets, J. D. Assink, S. Shani‐Kadmiel, K. Kondo, S. Sugiyama
    Geophysical Research Letters 49 8 2022年04月28日 [査読有り]
  • Tatsuya WATANABE, Shintaro YAMASAKI, Shin SUGIYAMA
    Journal of the Japan Landslide Society 59 2 50 - 59 2022年
  • Evgeny A. Podolskiy, Yoshio Murai, Naoya Kanna, Shin Sugiyama
    The Journal of the Acoustical Society of America 151 1 6 - 16 2022年01月 [査読有り]
  • Shin Sugiyama, Masahiro Minowa, Yasushi Fukamachi, Shuntaro Hata, Yoshihiro Yamamoto, Tobias Sauter, Christoph Schneider, Marius Schaefer
    Nature Communications 12 1 6301  2021年11月 [査読有り][通常論文]
     
    AbstractWater temperature in glacial lakes affects underwater melting and calving of glaciers terminating in lakes. Despite its importance, seasonal lake temperature variations are poorly understood because taking long-term measurements near the front of calving glaciers is challenging. To investigate the thermal structure and its seasonal variations, we performed year-around temperature and current measurement at depths of 58–392 m in Lago Grey, a 410-m-deep glacial lake in Patagonia. The measurement revealed critical impacts of subglacial discharge on the lake thermal condition. Water below a depth of ~100 m showed the coldest temperature in mid-summer, under the influence of glacial discharge, whereas temperature in the upper layer followed a seasonal variation of air temperature. The boundary of the lower and upper layers was controlled by the depth of a sill which blocks outflow of dense and cold glacial meltwater. Our data implies that subglacial discharge and bathymetry dictate mass loss and the retreat of lake-terminating glaciers. The cold lakewater hinders underwater melting and facilitates formation of a floating terminus.
  • Yefan Wang, Shin Sugiyama, Anders A. Bjørk
    Journal of Geophysical Research: Earth Surface 2021年10月20日 [査読有り][通常論文]
  • Masahiro Minowa, Shin Sugiyama, Masato Ito, Shiori Yamane, Shigeru Aoki
    Nature Communications 12 1 2021年07月 
    AbstractBasal melting of ice shelves is considered to be the principal driver of recent ice mass loss in Antarctica. Nevertheless, in-situ oceanic data covering the extensive areas of a subshelf cavity are sparse. Here we show comprehensive structures of temperature, salinity and current measured in January 2018 through four boreholes drilled at a ~3-km-long ice shelf of Langhovde Glacier in East Antarctica. The measurements were performed in 302–12 m-thick ocean cavity beneath 234–412 m-thick ice shelf. The data indicate that Modified Warm Deep Water is transported into the grounding zone beneath a stratified buoyant plume. Water at the ice-ocean interface was warmer than the in-situ freezing point by 0.65–0.95°C, leading to a mean basal melt rate estimate of 1.42 m a−1. Our measurements indicate the existence of a density-driven water circulation in the cavity beneath the ice shelf of Langhovde Glacier, similar to that proposed for warm-ocean cavities of larger Antarctic ice shelves.
  • Evgeny A. Podolskiy, Yoshio Murai, Naoya Kanna, Shin Sugiyama
    Nature Communications 12 1 2021年06月 [査読有り][通常論文]
     
    AbstractShearing along subduction zones, laboratory experiments on analogue faults, and sliding along glacier beds are all associated with aseismic and co-seismic slip. In this study, an ocean-bottom seismometer is deployed near the terminus of a Greenlandic tidewater glacier, effectively insulating the signal from the extremely noisy surface seismic wavefield. Continuous, tide-modulated tremor related to ice speed is recorded at the bed of the glacier. When noise interference (for example, due to strong winds) is low, the tremor is also confirmed via analysis of seismic waveforms from surface stations. The signal resembles the tectonic tremor commonly observed during slow-earthquake events in subduction zones. We propose that the glacier sliding velocity can be retrieved from the observed seismic noise. Our approach may open new opportunities for monitoring calving-front processes in one of the most difficult-to-access cryospheric environments.
  • Evgeny A. Podolskiy, Yoshio Murai, Naoya Kanna, Shin Sugiyama
    Seismological Research Letters 2021年05月05日 [査読有り][通常論文]
     
    Abstract About 70% of Earth’s surface is covered by ocean, for which seismic observations are challenging. Seafloor seismology overcame this fundamental difficulty and radically transformed the earth sciences, as it expanded the coverage of seismic networks and revealed otherwise inaccessible features. At the same time, there has been a recent increase in the number of studies on cryoseismology. These have yielded multiple discoveries but are limited primarily to land and ice-surface receivers. Near ice calving fronts, such surface stations are noisy, primarily due to crevassing and wind, are hazardous to maintain, and can be lost due to iceberg calving. To circumvent these issues, we have applied ocean-bottom seismology to the calving front of a tidewater glacier in northwest Greenland. We present details of this experiment, and describe the technical challenges, noise analysis, and examples of recorded data. This includes tide-modulated seismicity with thousands of icequakes per day and the first near-source (∼200–640  m) underwater record of a major kilometer-scale calving event in Greenland, which generated a glacial earthquake that was detectable ∼420  km away. We also identified a decrease in bottom-water temperature, presumably due to modified water stratification driven by extreme Greenland glacial melting, at the end of July 2019. Importantly, we identify glacial sediments as the key reason for the anomalously long (∼9.7  hr) delay in the sensor release from the fjord seafloor. Our study demonstrates a methodology to undertake innovative, interdisciplinary, near-source studies on glacier basal sliding, calving, and marine-mammal vocalizations.
  • Masahiro Minowa, Marius Schaefer, Shin Sugiyama, Daiki Sakakibara, Pedro Skvarca
    Earth and Planetary Science Letters 561 116811 - 116811 2021年05月 [査読有り][通常論文]
     
    The complex dynamics of calving glaciers is a major uncertainty in projecting global glacial mass loss. We present frontal ablation and ice mass change for the 38 major calving glaciers in the Patagonian icefields based on remote-sensing observations of ice-front positions, surface speeds and elevation changes. The frontal ablation from 2000 to 2019 was -24.1 +/- 1.7 Gt a(-1), which represents 34 +/- 6% of the total ablation of the icefields. The fraction of frontal ablation was close to half in the southern icefield and about one fifth in the northern icefield. The rate of the mass loss from the icefields during the period of study was 15.2 +/- 3.5 Gt a(-1), which is generally explained by surface mass balance but was accelerated as a result of increasing frontal ablation. The frontal ablation and mass change values suggest surface mass balance to be -1.5 +/- 0.9 Gt a(-1) for the northern icefield and +11.5 +/- 2.7 Gt a(-1) for the southern icefield during this period. Our study demonstrates that a strong increase in frontal ablation at several glaciers drives the mass loss in the southern icefield, whereas increasingly negative surface mass balance drives the mass loss in the northern icefield. (C) 2021 Elsevier B.V. All rights reserved.
  • Evgeny A. Podolskiy, Naoya Kanna, Shin Sugiyama
    Communications Earth & Environment 2 1 2021年03月25日 [査読有り][通常論文]
     
    AbstractIn the Arctic, subglacial discharge plumes have been recently recognised as a key driver of fjord-scale circulation. However, owing to the danger that accompanies prolonged observations at plumes, no time-series data are available. Here, we present results showing the chaotic and irregular dynamics of a plume revealed by continuous subsurface monitoring directly on the calving front of a Greenlandic glacier. We found intense fluctuations in the current and scalars (temperature and salinity), recognised shallow and deep tidal modulation and anomalies due to co-seismic drainage of an ice-dammed lake via the plume, and observed rapid and marked changes in stratification. Our analysis uncovers energy cascade intermittency with coherent structures, corresponding to upwelling pulses of warm water. Prior to our research, in situ evidence of time-variable plume dynamics was absent and limited to snapshots, therefore, our study and approach will enable researchers to transition from an episodic view of a plume to a continuously updated image.
  • 杉山慎, 近藤研
    雪氷 83 2 193 - 204 2021年03月 [査読有り][通常論文]
  • Ken Kondo, Shin Sugiyama, Daiki Sakakibara, Shungo Fukumoto
    Journal of Glaciology 1 - 11 2021年02月17日 
    Abstract As a result of climate warming, glacial meltwater discharge has been increasing in Greenland. During the summers of 2015 and 2016, there were rapid increases in discharge from Qaanaaq Glacier in northwestern Greenland. These discharges resulted in floods that destroyed the road linking the settlement of Qaanaaq to Qaanaaq Airport. Field measurements were performed and a numerical model of glacier runoff was developed to quantify these discharges. The high discharge associated with the 2015 flood, estimated at 9.1 m3 s−1 (hourly mean), resulted from intensive glacier melting due to warm air temperature and strong winds, while the high discharge associated with the 2016 flood resulted from heavy rainfall (90 mm d−1) that led to a peak discharge estimated at 19.9 m3 s−1. The developed model, when used to investigate future glacier runoff under warming conditions, revealed a nonlinear increase in glacial melt with increasing temperature. Additionally, the model forecasted a threefold increase in total summer discharge, owing to a 4 °C rise in temperature. Thus, this study quantified the impact of a changing climate on glacier runoff, which gives insight into future risks of flood hazards along the coast of Greenland.
  • Eef C. H. van Dongen, Guillaume Jouvet, Shin Sugiyama, Evgeny A. Podolskiy, Martin Funk, Douglas I. Benn, Fabian Lindner, Andreas Bauder, Julien Seguinot, Silvan Leinss, Fabian Walter
    The Cryosphere 15 2 485 - 500 2021年02月02日 [査読有り][通常論文]
     
    Abstract. Ice mass loss from the Greenland ice sheet is the largest single contributor to sea level rise in the 21st century. The mass loss rate has accelerated in recent decades mainly due to thinning and retreat of its outlet glaciers. The diverse calving mechanisms responsible for tidewater glacier retreat are not fully understood yet. Since a tidewater glacier’s sensitivity to external forcings depends on its calving style, detailed insight into calving processes is necessary to improve projections of ice sheet mass loss by calving. As tidewater glaciers are mostly thinning, their calving styles are expected to change. Here, we study calving behaviour changes under a thinning regime at Bowdoin Glacier, north-western Greenland, by combining field and remote-sensing data from 2015 to 2019. Previous studies showed that major calving events in 2015 and 2017 were driven by hydro-fracturing and melt-undercutting. New observations from uncrewed aerial vehicle (UAV) imagery and a GPS network installed at the calving front in 2019 suggest ungrounding and buoyant calving have recently occurred as they show (1) increasing tidal modulation of vertical motion compared to previous years, (2) absence of a surface crevasse prior to calving, and (3) uplift and horizontal surface compression prior to calving. Furthermore, an inventory of calving events from 2015 to 2019 based on satellite imagery provides additional support for a change towards buoyant calving since it shows an increasing occurrence of calving events outside of the melt season. The observed change in calving style could lead to a possible retreat of the terminus, which has been stable since 2013. We therefore highlight the need for high-resolution monitoring to detect changing calving styles and numerical models that cover the full spectrum of calving mechanisms to improve projections of ice sheet mass loss by calving.
  • Shuntaro Hata, Shin Sugiyama
    Frontiers in Earth Science 8 576044  2021年01月21日 [査読有り][通常論文]
     
    Glaciar Pío XI has advanced and thickened over the past several decades in contrast to the generally retreating and thinning trends seen in other glaciers in the Southern Patagonia Icefield (SPI). To quantify recent changes in ice-front positions and glacier surface elevation over the ablation area of Glaciar Pío XI, we analyzed satellite data acquired from 2000 to 2018. Two major glacier termini, and most of the small outlet glaciers, showed advancing trends, including the largest advance (1,400 m), observed at the southern terminus during the study period. Surface elevation increased by 37.3 ± 0.4 m as a mean over the study area, and the rate of the increase accelerated by 135 ± 10% from Period 1 (2000–2007) to Period 2 (2007–2017/18). Elevation change during Period 1 was only slightly positive except for extraordinary thickening (∼20 m a−1) observed near the southern terminus and one of the outlet glacier fronts, whereas significant thickening (∼2.7 m a−1) occurred over the entire ablation area during Period 2. Satellite imagery showed an emergence of sedimentary mounds in front of the southern terminus, suggesting that reduction in frontal ablation and increasingly compressive flow regime are the main drivers of the recent rapid thickening and advance. Most likely, the influence of the sediment deposition on the southern terminus subsequently propagated to the northern terminus and upper reaches of the glacier. The rate of ice mass increase during the study period was 0.48 ± 0.03 Gt a−1, which corresponds to 4% of the total mass loss from the SPI from 2000 to 2015/16.
  • 杉山 慎, 箕輪昌紘, 伊藤優人, 山根志織
    雪氷 83 1 13 - 25 2021年01月 [査読有り][通常論文]
  • Shin Sugiyama, Naoya Kanna, Daiki Sakakibara, Takuto Ando, Izumi Asaji, Ken Kondo, Yefan Wang, Yoshiki Fujishi, Shungo Fukumoto, Evgeniy Podolskiy, Yasushi Fukamachi, Minori Takahashi, Sumito Matoba, Yoshinori Iizuka, Ralf Greve, Masato Furuya, Kazutaka Tateyama, Tatsuya Watanabe, Shintaro Yamasaki, Atsushi Yamaguchi, Bungo Nishizawa, Kohei Matsuno, Daiki Nomura, Yuta Sakuragi, Yoshimasa Matsumura, Yoshihiko Ohashi, Teruo Aoki, Masashi Niwano, Naotaka Hayashi, Masahiro Minowa, Guillaume Jouvet, Eef van Dongen, Andreas Bauder, Martin Funk, Anders Anker Bjørk, Toku Oshima
    Polar Science 27 100632 - 100632 2020年12月
  • Kenneth D. Mankoff, Brice Noël, Xavier Fettweis, Andreas P. Ahlstrøm, William Colgan, Ken Kondo, Kirsty Langley, Shin Sugiyama, Dirk van As, Robert S. Fausto
    Earth System Science Data 12 4 2811 - 2841 2020年11月14日 [査読有り]
     
    Abstract. Greenland runoff, from ice mass loss and increasing rainfall, is increasing. That runoff, as discharge, impacts the physical, chemical, and biological properties of the adjacent fjords. However, where and when the discharge occurs is not readily available in an open database. Here we provide data sets of high-resolution Greenland hydrologic outlets, basins, and streams, as well as a daily 1958 through 2019 time series of Greenland liquid water discharge for each outlet. The data include 24 507 ice marginal outlets and upstream basins and 29 635 land coast outlets and upstream basins, derived from the 100 m ArcticDEM and 150 m BedMachine. At each outlet there are daily discharge data for 22 645 d – ice sheet runoff routed subglacially to ice margin outlets and land runoff routed to coast outlets – from two regional climate models (RCMs; MAR and RACMO). Our sensitivity study of how outlet location changes for every inland cell based on subglacial routing assumptions shows that most inland cells where runoff occurs are not highly sensitive to those routing assumptions, and outflow location does not move far. We compare RCM results with 10 gauges from streams with discharge rates spanning 4 orders of magnitude. Results show that for daily discharge at the individual basin scale the 5 % to 95 % prediction interval between modeled discharge and observations generally falls within plus or minus a factor of 5 (half an order of magnitude, or +500 %/-80 %). Results from this study are available at https://doi.org/10.22008/promice/freshwater (Mankoff, 2020a) and code is available at http://github.com/mankoff/freshwater (last access: 6 November 2020) (Mankoff, 2020b).
  • N. Kanna, S. Sugiyama, Y. Fukamachi, D. Nomura, J. Nishioka
    Global Biogeochemical Cyscles 34 10 e2020GB006567  American Geophysical Union 2020年09月28日 [査読有り][通常論文]
  • K Matsuno, N Kanna, S Sugiyama, A Yamaguchi, EJ Yang
    Marine Ecology Progress Series 642 55 - 65 2020年05月28日 [査読有り][通常論文]
     
    To evaluate the effects of meltwater discharge from marine-terminating glaciers on a fjord protist community in northwestern Greenland during summer, we investigated the distribution, abundance and biomass of the protist community and their relationships with hydrographic parameters. In the standing stock of protists, dinoflagellates (46.4%) and oligotrich ciliates (39.5%) were dominant throughout the study region. With respect to vertical distribution, oligotrich ciliates were abundant in the surface layer, mainly due to suitable food conditions (abundance of diatom and nanoflagellates). Near glaciers, relatively high chlorophyll a (chl a) concentrations were found in the subsurface layers associated with the low-temperature, high-turbidity and slightly high nutrient levels, indicating that the nutrient inputs from the upwelling glacial meltwater plume increased primary production. Large-sized Protoperidium spp. were found only at stations near glaciers where nutrients were abundant, and heterotrophic dinoflagellates showed strong relationships with nanoflagellates. These findings suggest that the upwelling associated with subglacial meltwater discharge can stimulate nanoflagellate production, resulting in increases in ciliate and heterotrophic dinoflagellate production.
  • Podolskiy, J., S. Sugiyama
    Journal of Geophysical Research Oceans 125 e2020JC016116  2020年05月 [査読有り][通常論文]
  • Ohashi, Y., S. Aoki, Y. Matsumura, S. Sugiyama, N. Kanna, D. Sakakibara
    Ocean Science 16 545 - 564 2020年04月 [査読有り][通常論文]
  • Through the Japanese field research in Greenland: A changing natural environment and its impact on human society
    Sugiyama, S.
    Polar Record 1 - 6 2020年04月 [査読有り][通常論文]
  • J. Seguinot, M. Funk, A. Buder, T. Wyder, C. Senn, S. Sugiyama
    Frontiers in Earth Science 8 65  2020年03月 [査読有り][通常論文]
  • Van Dongen, E, G. Jouvet, A. Walter, J. Todd, T. Zwinger, I. Asaji, S. Sugiyama, F. Walter, M. Funk
    Journal of Glaciology 66 255 113 - 123 2020年02月 [査読有り][通常論文]
  • Sakakibara, D, S. Sugiyama
    Journal of Glaciology 66 255 25 - 34 2020年02月 [査読有り][通常論文]
  • Nishizawa, B, N. Kanna, Y. Abe, Y. Ohashi, D. Sakakibara, I. Asaji, S. Sugiyama, A. Yamaguchi, Y. Watanuki
    ICES Journal of Marine Science fsz213 2019年12月 [査読有り][通常論文]
  • Tsutaki, Shun, Fujita, Koji, Nuimura, Takayuki, Sakai, Akiko, Sugiyama, Shin, Komori, Jiro, Tshering, Phuntsho
    CRYOSPHERE 13 10 2733 - 2750 2019年10月 [査読有り][通常論文]
     
    Despite the importance of glacial lake development in ice dynamics and glacier thinning, in situ and satellite-based measurements from lake-terminating glaciers are sparse in the Bhutanese Himalaya, where a number of proglacial lakes exist. We acquired in situ and satellite-based observations across lake- and land-terminating debris-covered glaciers in the Lunana region, Bhutanese Himalaya. A repeated differential global positioning system survey reveals that thickness change of the debris-covered ablation area of the lake-terminating Lugge Glacier (-4.67 +/- 0.07 m a(-1)) is more than 3 times more negative than that of the land-terminating Thorthormi Glacier (-1 40 +/- 0.07 m a(-1)) for the 2004-2011 period. The surface flow velocities decrease down-glacier along Thorthormi Glacier, whereas they increase from the upper part of the ablation area to the terminus of Lugge Glacier. Numerical experiments using a two-dimensional ice flow model demonstrate that the rapid thinning of Lugge Glacier is driven by both a negative surface mass balance and dynamically induced ice thinning. However, the thinning of Thorthormi Glacier is minimised by a longitudinally compressive flow regime. Multiple supraglacial ponds on Thorthormi Glacier have been expanding since 2000 and have merged into a single proglacial lake, with the glacier terminus detaching from its terminal moraine in 2011. Numerical experiments suggest that the thinning of Thorthormi Glacier will accelerate with continued proglacial lake development.
  • Minowa, M, E. A. Podolskiy, S. Sugiyama
    Annals of Glaciology 60 79 57 - 67 2019年06月 [査読有り][通常論文]
     
    We recorded the ice motion and icequakes on the floating part of Langhovde Glacier in East Antarctica to better understand the dynamic behavior of ice shelves and floating tongues. Diurnal and semi-diurnal variations in ice motion and seismicity were simultaneously observed at all four global navigation satellite system and three seismic stations over 2 weeks. The short-term along-flow ice motion is explained by the elastic response of the glacier to ocean tide-induced hydrostatic stress variations, which decayed at a rate of 0.8 km(-1) toward the grounding line. We observed a large number of icequakes during mid-rising and high tides that covered a broad frequency range and formed two major groups of events centered at 10 and 120 Hz, respectively. The hourly occurrence rates were similar to 500 events h(-1), with the observed seismicity consistent with fracture due to floating tongue bending. We also observed minor secondary peaks at high ice speeds, which could reflect surface cracking due to stretching or basal friction. Our observation demonstrates that tidal-modulation was the main factor to fracture the floating tongue of Langhovde Glacier.
  • Minowa, M, E. A. Podolskiy, G. Jouvet, Y. Weidmann, D. Sakakibara, S. Tsutaki, E. Genco, S. Sugiyama
    Earth and Planetary Science Letters 515 283 - 290 2019年06月 [査読有り][通常論文]
     
    Measuring glacier calving magnitude, frequency and location in high temporal resolution is necessary to understand mass loss mechanisms of ocean-terminating glaciers. We utilized calving-generated tsunami signals recorded with a pressure sensor for estimating the calving flux of Bowdoin Glacier in northwestern Greenland. We find a relationship between calving ice volume and wave amplitude. This relationship was used to compute calving flux variation. The calving flux showed large spatial and temporal fluctuations in July 2015 and in July 2016, with a mean flux of 2.3 +/- 0.15 x 10(5) m(3) d(-1). Calving flux was greater during periods of fast ice flow, high air temperature, and at low/falling tide, indicating the importance of increased longitudinal strain due to glacier acceleration and/or submarine melting at the calving front. Long-term measurements with the method introduced here are promising for understanding the complex interplay of ice dynamics, melting and calving at glacier fronts. (C) 2019 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
  • Seddik H, Greve R, Sakakibara D, Tsutaki S, Minowa M, Sugiyama S
    Journal of Glaciology 65 250 225 - 238 2019年03月 [査読有り][通常論文]
     
    We use the full-Stokes model Elmer/Ice to investigate the present dynamics of Bowdoin Glacier, a marine-terminating outlet glacier in northwestern Greenland. Short-term speed variations of the glacier were observed, correlating with air temperature and precipitation, and with the semi-diurnal ocean tides. We use a control inverse method to determine the distribution of basal friction. This reveals that most of the glacier area is characterized by near-plug-flow conditions, while some sticky spots are also identified. We then conduct experiments to test the sensitivity of the glacier flow to basal lubrication and tidal forcing at the calving front. Reduction of the basal drag by 10-40% produces speed-ups that agree approximately with the observed range of speed-ups that result from warm weather and precipitation events. In agreement with the observations, tidal forcing and surface speed near the calving front are found to be in anti-phase (high tide corresponds to low speed, and vice versa). However, the amplitude of the semi-diurnal variability is underpredicted by a factor similar to 3, which is likely related to either inaccuracies in the surface and bedrock topographies or mechanical weakening due to crevassing.
  • Sugiyama, S, M. Minowa, M. Schaefer
    Geophysical Research Letters 46 5 2602 - 2609 2019年02月 [査読有り][通常論文]
     
    Underwater ice geometry at the front of calving glaciers provides crucial information for calving and underwater melting. In this study, we present ice geometry captured by operating a side-scanning sonar near the front of Glaciar Grey, a freshwater calving glacier in Patagonia. The observations revealed ice projecting into the lake with a substantially different structure from that of known tidewater glaciers. Terrace-like ice structures were found at several tens of meters below the water surface and extended up to 100m from the aerial ice front. The structure depicted by the sonar was confirmed when the ice front was exposed by flotation during a major calving event. We infer that buoyant force acting on the submerged ice terrace acted as a driver of the calving event. Our study demonstrates the importance of the underwater ice geometry, which affects sizable calving at the front of freshwater calving glaciers.Plain Language Summary Glaciers terminating in lakes and the ocean are in general retreating more rapidly than glaciers on land. This is because such glaciers lose ice by discharging icebergs and melting in water. The shape of the submerged part of the ice front provides important information for understanding iceberg production and melting, but measurements near the glacier front are difficult to obtain. In this study, we used a side-scanning sonar to visualize underwater ice of a lake terminating glacier in Patagonia. The observations revealed ice jutting into the lake, forming terrace-like structures several tens of meters below the water surface. The structure was significantly different from that of ocean terminating glaciers. The observation was confirmed when the ice front was detached from the glacier and exposed by flotation. Our study demonstrates that buoyant force acting on the ice terrace plays a key role in the production of large icebergs at the front of freshwater calving glaciers.
  • Sugiyama, S., Navarro, F.J., Sawagaki, T., Minowa, M., Segawa, T., Onuma, Y., Otero, J., Vasilenko, E.V.
    Journal of Glaciology 65 252 689 - 699 2019年 [査読有り][通常論文]
  • Naito, A, Y. Abe, K. Matsuno, B. Nishizawa, N. Kanna, S. Sugiyama, A. Yamaguchi
    Polar Science 2019年01月 [査読有り][通常論文]
  • T. Segawa, R. Matsuzaki, N. Takeuchi, A. Akiyoshi, F. Navarro, S. Sugiyama, T. Yonezawa, H. Mori
    Nature Communications 9 1 3094 - 3094 2018年08月 [査読有り][通常論文]
     
    Red-snow algae are red-pigmented unicellular algae that appear seasonally on the surface of thawing snow worldwide. Here, we analyse the distribution patterns of snow algae sampled from glaciers and snow patches in the Arctic and Antarctica based on nuclear ITS2 sequences, which evolve rapidly. The number of phylotypes is limited in both polar regions, and most are specific to either the Arctic or Antarctica. However, the bipolar phylotypes account for the largest share (37.3%) of all sequences, suggesting that red-algal blooms in polar regions may comprise mainly cosmopolitan phylotypes but also include endemic organisms, which are distributed either in the Arctic or Antarctica.
  • Jouvet, G, Y. Weidmann, M. Kneib, M. Detert, J. Seguinot, D. Sakakibara, S. Sugiyama
    Remote Sensing of Environment 217 389 - 399 2018年08月 [査読有り][通常論文]
  • Masahiro Minowa, Evgeny A. Podolskiy, Shin Sugiyama, Daiki Sakakibara, Pedro Skvarca
    Journal of Glaciology 64 245 362 - 376 2018年06月01日 [査読有り][通常論文]
     
    Calving plays a key role in the recent rapid retreat of glaciers around the world. However, many processes related to calving are poorly understood since direct observations are scarce and challenging to obtain. When calving occurs at a glacier front, surface-water waves arise over the ocean or a lake in front of glaciers. To study calving processes from these surface waves, we performed field observations at Glaciar Perito Moreno, Patagonia. We synchronized time-lapse photography and surface waves record to confirm that glacier calving produces distinct waves compared with local noise. A total of 1074 calving events were observed over the course of 39 d. During austral summer, calving occurred twice more frequently than in spring. The cumulative distribution of calving-interevent time interval followed exponential model, implying random occurrence of events in time. We further investigated wave properties and found that source-to-sensor distance can be estimated from wave dispersion within ∼20% error. We also found that waves produced by different calving types showed similar spectra in the same frequency range between 0.05-0.2 Hz, and that the amplitude of surface waves increased with the size of calving. This study demonstrates the potential of surface-wave monitoring for understanding calving processes.
  • Naoya Kanna, Shin Sugiyama, Yoshihiko Ohashi, Daiki Sakakibara, Yasushi Fukamachi, Daiki Nomura
    Journal of Geophysical Research: Biogeosciences 123 5 1666 - 1682 2018年05月 [査読有り][通常論文]
  • Daiki Sakakibara, Shin Sugiyama
    Journal of Glaciology 64 244 300 - 310 2018年04月01日 [査読有り][通常論文]
     
    Satellite images were analyzed to measure the frontal positions and ice speeds of 19 marine-terminating outlet glaciers along the coast of Prudhoe Land, northwestern Greenland from 1987 to 2014. All the studied glaciers retreated over the study period at a rate of between 12 and 200 m a-1, with a median (mean) retreat rate of 30 (40) m a-1. The glacier retreat began in the year ~2000, which coincided with an increase in summer mean air temperature from 1.4 to 5.5 °C between 1996 and 2000 in this region. Ice speed near the front of the studied glaciers ranged between 20 and 1740 m a-1 in 2014, and many of them accelerated in the early 2000s. In general, the faster retreat was observed at the glaciers that experienced greater acceleration, as represented by Tracy Glacier, which experienced a retreat of 200 m a-1 and a velocity increase of 930 m a-1 during the study period. A possible interpretation of this observation is that flow acceleration induced dynamic thinning near the termini, resulting in enhanced calving and rapid retreat of the studied glaciers. We hypothesize that atmospheric warming conditions in the late 1990s triggered glacier retreat in northwestern Greenland since 2000.
  • Matoba, S, M. Niwano, T. Tanikawa, Y. Iizuka, T. Yamasaki, Y. Kurosaki, T. Aoki, A. Hashimoto, M. Hosaka, S. Sugiyama
    Bulletin of Glaciological Research 36 0 15 - 22 2018年 [査読有り][通常論文]
  • Tsutaki, S, S. Sugiyama, D. Sakakibara
    Polar Data Journal 1 1 - 16 2017年10月 [査読有り][通常論文]
  • 杉山 慎
    雪氷 79 5 443 - 449 日本雪氷学会 2017年09月 [査読有り][招待有り]
  • Hakime Seddik, Ralf Greve, Thomas Zwinger, Shin Sugiyama
    CRYOSPHERE 11 5 2213 - 2229 2017年09月 [査読有り][通常論文]
     
    A hierarchy of approximations of the force balance for the flow of grounded ice exists, ranging from the most sophisticated full Stokes (FS) formulation to the most simplified shallow ice approximation (SIA). Both are implemented in the ice flow model Elmer/Ice, and we compare them by applying the model to the East Antarctic Shirase drainage basin. First, we apply the control inverse method to infer the distribution of basal friction with FS. We then compare FS and SIA by simulating the flow of the drainage basin under present-day conditions and for three scenarios 100 years into the future defined by the SeaRISE (Sea-level Response to Ice Sheet Evolution) project. FS reproduces the observed flow pattern of the drainage basin well, in particular the zone of fast flow near the grounding line, while SIA generally overpredicts the surface velocities. As for the transient scenarios, the ice volume change (relative to the constant-climate control run) of the surface climate experiment is nearly the same for FS and SIA, while for the basal sliding experiment (halved basal friction), the ice volume change is similar to 30% larger for SIA than for FS. This confirms findings of earlier studies that, in order to model ice sheet areas containing ice streams and outlet glaciers with high resolution and precision, careful consideration must be given to the choice of a suitable force balance.
  • Shun Tsutaki, Shin Sugiyama, Daiki Sakakibara, Teruo Aoki, Masashi Niwano
    Annals of Glaciology 58 75 181 - 192 2017年07月01日 [査読有り][通常論文]
     
    To better understand the processes controlling recent mass loss of peripheral glaciers and ice caps in northwestern Greenland, we measured surface mass balance (SMB), ice velocity and near-surface ice temperature on Qaanaaq Ice Cap in the summers of 2012-16. The measurements were performed along a survey route spanning the terminus of an outlet glacier to the upper reaches (243-968 m a.s.l.). The ice-cap-wide SMB ranged from -1.10 ± 0.29 to -0.13 ± 0.26 m w.e. a-1 for the years from 2012/13 to 2015/16. Mass balance showed substantially large fluctuations over the study period under the influence of summer temperature and snow accumulation. Ice velocity showed seasonal speedup only in the summer of 2012, suggesting an extraordinary amount of meltwater penetrated to the bed and enhanced basal ice motion. Ice temperature at a depth of 13 m was -8.0°C at 944 m a.s.l., which was 2.5°C warmer than that at 243 m a.s.l., suggesting that ice temperature in the upper reaches was elevated by refreezing and percolation of meltwater. Our study provided in situ data from a relatively unstudied region in Greenland, and demonstrated the importance of continued monitoring of these processes for longer timespans in the future.
  • Guillaume Jouvet, Yvo Weidmann, Julien Seguinot, Martin Funk, Takahiro Abe, Daiki Sakakibara, Hakime Seddik, Shin Sugiyama
    CRYOSPHERE 11 2 911 - 921 2017年04月 [査読有り][通常論文]
     
    In this paper, we analyse the calving activity of the Bowdoin Glacier, north-western Greenland, in 2015 by combining satellite images, UAV (unmanned aerial vehicle) photogrammetry and ice flow modelling. In particular, a high-resolution displacement field is inferred from UAV orthoimages taken immediately before and after the initiation of a large fracture, which induced a major calving event. A detailed analysis of the strain rate field allows us to accurately map the path taken by the opening crack. Modelling results reveal (i) that the crack was more than half-thickness deep, filled with water and getting irreversibly deeper when it was captured by the UAV and (ii) that the crack initiated in an area of high horizontal shear caused by a local basal bump immediately behind the current calving front. The asymmetry of the bed at the front explains the systematic calving pattern observed in May and July-August 2015. As a corollary, we infer that the calving front of the Bowdoin Glacier is currently stabilized by this bedrock bump and might enter into an unstable mode and retreat rapidly if the glacier keeps thinning in the coming years. Beyond this outcome, our study demonstrates that the combination of UAV photogrammetry and ice flow modelling is a promising tool to horizontally and vertically track the propagation of fractures responsible for large calving events.
  • Masahiro Minowa, Shin Sugiyama, Daiki Sakakibara, Pedro Skvarca
    Frontiers in Earth Science 5 2017年01月24日 [査読有り][通常論文]
     
    The front position of calving glaciers is controlled by ice speed and frontal ablation which consists of the two processes of calving and subaqueous melting. However, the relative importance of these processes in frontal variation is difficult to assess and poorly understood, particularly for freshwater calving glaciers. To better understand the mechanism of seasonal variations involved in the ice front variations of freshwater calving glaciers, we measured front position, ice surface speed, air temperature, and proglacial lakewater temperature of Glaciar Perito Moreno in Patagonia. No substantial fluctuations in front position and ice speed occurred during the 15-year period studied (1999-2013), despite a warming trend in air temperature (0.059°C a-1). Seasonal variations were observed both in the ice-front position (±50 m) and ice speed (±15%). The frontal ablation rate, computed from the frontal displacement rate and the ice speed, varied in a seasonal manner with an amplitude approximately five times greater than that in the ice speed. The frontal ablation correlated well with seasonal lakewater temperature variations (r = 0.96) rather than with air temperature (r = 0.86). Our findings indicate that the seasonal ice front variations of Glaciar Perito Moreno are primarily due to frontal ablation, which is controlled through subaqueous melting by the thermal conditions of the lake.
  • 榊原 大貴, 庭野 匡思, 杉山 慎
    雪氷研究大会講演要旨集 2017 289 - 289 公益社団法人 日本雪氷学会/日本雪工学会 2017年
  • 的場 澄人, 庭野 匡思, 谷川 朋範, 飯塚 芳徳, 山崎 哲秀, 黒﨑 豊, 青木 輝夫, 橋本 明弘, 保坂 征宏, 杉山 慎
    雪氷研究大会講演要旨集 2017 288 - 288 公益社団法人 日本雪氷学会/日本雪工学会 2017年
  • 羽月 稜, 黒﨑 豊, 的場 澄人, 杉山 慎
    雪氷研究大会講演要旨集 2017 190 - 190 公益社団法人 日本雪氷学会/日本雪工学会 2017年
  • 山根 志織, 箕輪 昌紘, 杉山 慎
    雪氷研究大会講演要旨集 2017 169 - 169 公益社団法人 日本雪氷学会/日本雪工学会 2017年
  • 黒﨑 豊, 的場 澄人, 飯塚 芳徳, 青木 輝夫, 杉山 慎
    雪氷研究大会講演要旨集 2017 191 - 191 公益社団法人 日本雪氷学会/日本雪工学会 2017年
  • Shin Sugiyama, Masahiro Minowa, Daiki Sakakibara, Pedro Skvarca, Takanobu Sawagaki, Yoshihiko Ohashi, Nozomu Naito, Kazuhisa Chikita
    JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE 121 12 2270 - 2286 2016年12月 [査読有り][通常論文]
     
    Calving glaciers are rapidly retreating in many regions under the influence of ice-water interactions at the glacier front. In contrast to the numerous researches conducted on fjords in front of tidewater glaciers, very few studies have been reported on lakes in which freshwater calving glaciers terminate. To better understand ice-water interactions at the front of freshwater calving glaciers, we measured lakewater temperature, turbidity, and bathymetry near Glaciar Perito Moreno, Upsala, and Viedma, large calving glaciers of the Southern Patagonia Icefield. The thermal structures of these lakes were significantly different from those reported in glacial fjords. There was no indication of upwelling subglacial meltwater; instead, turbid and cold glacial water discharge filled the region near the lake bottom. This was because water density was controlled by suspended sediment concentrations rather than by water temperature. Near-surface wind-driven circulation reaches a depth of similar to 180 m, forming a relatively warm isothermal layer (mean temperature of similar to 5-6 degrees C at Perito Moreno, similar to 3-4 degrees C at Upsala, and similar to 6-7 degrees C at Viedma), which should convey heat energy to the ice-water interface. However, the deeper part of the glacier front is in contact with stratified cold water, implying a limited amount of melting there. In the lake in front of Glaciar Viedma, the region deeper than 120 m was filled entirely with turbid and very cold water at pressure melting temperature. Our results revealed a previously unexplored thermal structure of proglacial lakes in Patagonia, suggesting its importance in the subaqueous melting of freshwater calving glaciers.
  • Horst Machguth, Henrik H. Thomsen, Anker Weidick, Andreas P. Ahlstrom, Jakob Abermann, Morten L. Andersen, Signe B. Andersen, Anders A. Bjork, Jason E. Box, Roger J. Braithwaite, Carl E. Boggild, Michele Citterio, Poul Clement, William Colgan, Robert S. Fausto, Karin Gleie, Stefanie Gubler, Bent Hasholt, Bernhard Hynek, Niels T. Knudsen, Signe H. Larsen, Sebastian H. Mernild, Johannes Oerlemans, Hans Oerter, Ole B. Olesen, C. J. P. Paul Smeets, Konrad Steffen, Manfred Stober, Shin Sugiyama, Dirk van As, Michiel R. van den Broeke, Roderik S. W. van de Wal
    JOURNAL OF GLACIOLOGY 62 235 861 - 887 2016年10月 [査読有り][通常論文]
     
    Glacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes in glacier melt independently from model output. Here, we present a comprehensive database of Greenland glacier surface mass-balance observations from the ablation area of the ice sheet and local glaciers. The database spans the 123 a from 1892 to 2015, contains a total of similar to 3000 measurements from 46 sites, and is openly accessible through the PROMICE web portal (http://www.promice.dk). For each measurement we provide X, Y and Z coordinates, starting and ending dates as well as quality flags. We give sources for each entry and for all metadata. Two thirds of the data were collected from grey literature and unpublished archive documents. Roughly 60% of the measurements were performed by the Geological Survey of Denmark and Greenland (GEUS, previously GGU). The data cover all regions of Greenland except for the southernmost part of the east coast, but also emphasize the importance of long-term time series of which there are only two exceeding 20 a. We use the data to analyse uncertainties in point measurements of surface mass balance, as well as to estimate surface mass-balance profiles for most regions of Greenland.
  • Yoshihiko Ohashi, Takahiro Iida, Shin Sugiyama, Shigeru Aoki
    POLAR SCIENCE 10 3 270 - 277 2016年09月 [査読有り][通常論文]
     
    Glacial meltwater discharge from the Greenland ice sheet and ice caps forms high turbidity water in the proglacial ocean off the Greenland coast. Although the timing and magnitude of high turbidity water export affect the coastal marine environment, for example, through impacts on biological productivity, little is known about the characteristics of this high turbidity water. In this paper, we therefore report on the spatial and temporal variations in high turbidity water off the Thule region in northwestern Greenland, based on remote sensing, reflectance data at a wavelength of 555 nm (Rrs555). The high turbidity area, identified on the basis of high reflectivity (Rrs555 >= 0.0070 sr(-1)), was generally distributed near the coast, where many outlet glaciers terminate in the ocean and on land. The extent of the high turbidity area exhibited substantial seasonal and interannual variability, and its annual maximum extent was significantly correlated with summer air temperature. Assuming a linear relationship between the high turbidity area and summer temperature, annual maximum extent increases under the influence of increasing glacial meltwater discharge, as can be inferred from present and predicted future warming trends. (C) 2016 Elsevier B.V. and NIPR. All rights reserved.
  • Jun Saito, Shin Sugiyama, Shun Tsutaki, Takanobu Sawagaki
    POLAR SCIENCE 10 3 239 - 248 2016年09月 [査読有り][通常論文]
     
    A large number of glaciers and ice caps (GICs) are distributed along the Greenland coast, physically separated from the ice sheet. The total area of these GICs accounts for 5% of Greenland's ice cover. Melt water input from the GICs to the ocean substantially contributed to sea-level rise over the last century. Here, we report surface elevation changes of six ice caps near Qaanaaq (77 degrees 28'N, 69 degrees 13'W) in northwestern Greenland based on photogrammetric analysis of stereo pair satellite images. We processed the images with a digital map plotting instrument to generate digital elevation models (DEMs) in 2006 and 2010 with a grid resolution of 500 m. Generated DEMs were compared to measure surface elevation changes between 2006 and 2010. Over the study area of the six ice caps, covering 1215 km(2), the mean rate of elevation change was -1.1 +/- 0.1 m a(-1). This rate is significantly greater than that previously reported for the 2003-2008 period (-0.6 +/- 0.1 m a(-1)) for GICs all of northwestern Greenland. This increased mass loss is consistent with the rise in summer temperatures in this region at a rate of 0.12 degrees C a(-1) for the 1997-2013 period. (C) 2016 Elsevier B.V. and NIPR. All rights reserved.
  • Susanne Ingvander, Peter Jansson, Ian A. Brown, Shuji Fujita, Shin Sugyama, Sylviane Surdyk, Hiroyuki Enomoto, Margareta Hansson, Per Holmlund
    Antarctic Science 28 3 219 - 231 2016年06月 [査読有り]
     
    AbstractIn this study, snow particle size variability was investigated along a transect in Dronning Maud Land from the coast to the polar plateau. The aim of the study was to better understand the spatial and temporal variations in surface snow properties. Samples were collected twice daily during a traverse in 2007–08 to capture regional variability. Local variability was assessed by sampling in 10×10 m grids (5 m spacing) at selected locations. The particle size and shape distributions for each site were analysed through digital image analysis. Snow particle size variability is complex at different scales, and shows an internal variability of 0.18–3.31 mm depending on the sample type (surface, grid or pit). Relationships were verified between particle size and both elevation and distance to the coast (moisture source). Regional seasonal changes were also identified, particularly on the lower elevations of the polar plateau. This dataset may be used to quantitatively analyse the optical properties of surface snow for remote sensing. The details of the spatial and temporal variations observed in our data provide a basis for further studies of the complex and coupled processes affecting snow particle size and the interpretation of remote sensing of snow covered areas.
  • Evgeny A. Podolskiy, Shin Sugiyama, Martin Funk, Fabian Walter, Riccardo Genco, Shun Tsutaki, Masahiro Minowa, Maurizio Ripepe
    GEOPHYSICAL RESEARCH LETTERS 43 5 2036 - 2044 2016年03月 [査読有り][通常論文]
     
    Glacier microseismicity is a promising tool to study glacier dynamics. However, physical processes connecting seismic signals and ice dynamics are not clearly understood at present. Particularly, the relationship between tide-modulated seismicity and dynamics of calving glaciers remains elusive. Here we analyze records from an on-ice seismometer placed 250m from the calving front of Bowdoin Glacier, Greenland. Using high-frequency glacier flow speed measurements, we show that the microseismic activity is related to strain rate variations. The seismic activity correlates with longitudinal stretching measured at the glacier surface. Both higher melt rates and falling tides accelerate glacier motion and increase longitudinal stretching. Long-term microseismic monitoring could therefore provide insights on how a calving glacier's force balance and flow regime react to changes at the ice-ocean interface.
  • Shun Tsutaki, Shin Sugiyama, Daiki Sakakibara, Takanobu Sawagaki
    JOURNAL OF GLACIOLOGY 62 236 1083 - 1092 2016年 [査読有り][通常論文]
     
    To quantify recent thinning of marine-terminating outlet glaciers in northwestern Greenland, we carried out field and satellite observations near the terminus of Bowdoin Glacier. These data were used to compute the change in surface elevation from 2007 to 2013 and this rate of thinning was then compared with that of the adjacent land-terminating Tugto Glacier. Comparing DEMs of 2007 and 2010 shows that Bowdoin Glacier is thinning more rapidly (4.1 +/- 0.3 m a(-1)) than Tugto Glacier (2.8 +/- 0.3 m a(-1)). The observed negative surface mass-balance accounts for <40% of the elevation change of Bowdoin Glacier, meaning that the thinning of Bowdoin Glacier cannot be attributable to surface melting alone. The ice speed of Bowdoin Glacier increases down-glacier, reaching 457 m a(-1) near the calving front. This flow regime causes longitudinal stretching and vertical compression at a rate of -0.04 a(-1). It is likely that this dynamically-controlled thinning has been enhanced by the acceleration of the glacier since 2000. Our measurements indicate that ice dynamics indeed play a predominant role in the rapid thinning of Bowdoin Glacier.
  • 箕輪 昌紘, 杉山 慎
    雪氷研究大会講演要旨集 2015 186 - 186 公益社団法人 日本雪氷学会/日本雪工学会 2015年
  • 森本 直矢, 杉山 慎, 藤田 耕史
    雪氷研究大会講演要旨集 2015 189 - 189 公益社団法人 日本雪氷学会/日本雪工学会 2015年
  • Matoba, S., Motoyama, H., Fujita, K., Yamasaki, T., Minowa, M., Onuma, Y., Komuro, Y., Aoki, T., Yamaguchi, S., Sugiyama, S., Enomoto, H.
    Bulletin of Glaciological Research 33 7 - 14 2015年 [査読有り][通常論文]
  • Shin Sugiyama, Daiki Sakakibara, Shun Tsutaki, Mihiro Maruyama, Takanobu Sawagaki
    JOURNAL OF GLACIOLOGY 61 226 223 - 232 2015年 [査読有り][通常論文]
     
    To better understand recent rapid recession of marine-terminating glaciers in Greenland, we performed satellite and field observations near the calving front of Bowdoin Glacier, a 3 km wide outlet glacier in northwestern Greenland. Satellite data revealed a clear transition to a rapidly retreating phase in 2008 from a relatively stable glacier condition that lasted for >20 years. Ice radar measurements showed that the glacier front is grounded, but very close to the floating condition. These results, in combination with the results of ocean depth soundings, suggest bed geometry in front of the glacier is the primary control on the rate and pattern of recent rapid retreat. Presumably, glacier thinning due to atmospheric and/or ocean warming triggered the initial retreat. In situ measurements showed complex short-term ice speed variations, which were correlated with air temperature, precipitation and ocean tides. Ice speed quickly responded to temperature rise and a heavy rain event, indicating rapid drainage of surface water to the bed. Semi-diurnal speed peaks coincided with low tides, suggesting the major role of the hydrostatic pressure acting on the calving face in the force balance. These observations demonstrate that the dynamics of Bowdoin Glacier are sensitive to small perturbations occurring near the calving front.
  • Masahiro Minowa, Shin Sugiyama, Daiki Sakakibara, Takanobu Sawagaki
    ANNALS OF GLACIOLOGY 56 70 26 - 32 2015年 [査読有り][通常論文]
     
    Glaciar Perito Moreno (GPM) and Glaciar Ameghino (GA), Southern Patagonia Icefield, are in contact in the accumulation area, but have shown contrasting frontal variations in the past few decades. To investigate recent changes of the two glaciers and processes controlling the different responses to similar climate conditions, we measured surface elevation change from 2000 to 2008 and terminus positions from 1999 to 2012 using several types of satellite data. GPM shows no significant changes in terminus position and 0.4 +/- 0.3 m a(-1) thickening over the period, whereas GA retreated 55 +/- 2 m a(-1) and thinned 2.6 +/- 0.3 m a(-1). Mass-balance measurements over the period 1999/2000 show that accumulation at GPM was ten times greater than that at GA, but ablation was only three times greater. The mass-balance-altitude profile is similar for the two glaciers; differences in the mass-balance distribution are caused by differences in the accumulation-area ratio (AAR). Our results suggest that the AAR and the calving flux exert strong control on the evolution of glaciers in the region.
  • Takehiro Fukuda, Shin Sugiyama, Takanobu Sawagaki, Kazuki Nakamura
    ANTARCTIC SCIENCE 26 6 636 - 645 2014年12月 [査読有り][通常論文]
     
    To improve the understanding of the mechanism driving recent changes in outlet glaciers in East Antarctica, we measured changes in the terminus position, ice flow velocity and surface elevation of the Langhovde Glacier located on the Soya Coast. From satellite images from 2000-12 and field measurements taken in 2012 the glacier terminus position and flow velocity showed little change between 2003 and 2007. After this quiescent period, the glacier progressively advanced by 380m and the flow velocity increased near the calving front by 10m a(-1) from 2007-10. No significant change was observed in surface elevation during the study period. The changes in the terminus position and flow velocity imply a reduction in the calving rate from 93m a(-1) (2003-07) to 16m a(-1) (2007-10). This suggests that calving was inhibited by stable sea ice conditions in the ocean. Theses results indicate that the Langhovde Glacier was in a relatively stable condition during the study period, and its terminus position was controlled by the rate of calving under the influence of sea ice conditions.
  • Daiki Sakakibara, Shin Sugiyama
    JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE 119 11 2541 - 2554 2014年11月 [査読有り][通常論文]
     
    Patagonian icefields are losing volume, and their loss is due partly to rapid changes in their outlet glaciers that terminate in lakes or the ocean. Despite this key influence from outlet glaciers, relatively few of these calving glaciers have had high-frequency measurements on their frontal variations and ice speed changes. We describe here recent frontal variations and ice speed changes of all 28 major calving glaciers in the Southern Patagonia Icefield (SPI), including ice speed maps covering approximately half of the entire icefield. The analysis is based on satellite data from 1984 to 2011. Over this period, only the two termini of Glaciar Pio XI advanced. Of the remaining glacial fronts, 12 changed less than 0.5km, but 17 retreated at least 0.5km. In the latter group, three glacial fronts (Glaciar Jorge Montt, HPS12, and Upsala) retreated over 6km. Averaged over all 31 glacial fronts of the calving glaciers, the front positions retreated 1.56km (median is 0.71km). Along the flowline within 20km of the front, the ice speeds up to 5900200ma(-1). Except for regions showing large acceleration or deceleration, the mean speed over the measured area decreased by 30ma(-1) from 1984 to 2011. The three most rapidly retreating glaciers showed much larger acceleration near the calving front, suggesting that ice dynamics drive their rapid retreat. Thus, we see retreat as a long-term trend for the calving glaciers in the SPI, with behavior that implies a dynamically controlled rapid recession that may explain the recently reported volume change of the SPI.
  • Shin Sugiyama, Takanobu Sawagaki, Takehiro Fukuda, Shigeru Aoki
    EARTH AND PLANETARY SCIENCE LETTERS 399 52 - 60 2014年08月 [査読有り][通常論文]
     
    The grounding line (GL) of the Antarctic ice sheet forms the boundary between grounded and floating ice along the coast. Near this line, warm oceanic water contacts the ice shelf, producing the ice sheet's highest basal-melt rate. Despite the importance of this region, water properties and circulations near the GL are largely unexplored because in-situ observations are difficult. Here we present direct evidence of warm ocean-water transport to the innermost part of the subshelf cavity (several hundred meters seaward from the GL) of Langhovde Glacier, an outlet glacier in East Antarctica. Our measurements come from boreholes drilled through the glacier's similar to 400-m-thick grounding zone. Beneath the grounding zone, we find a 10-24-m-deep water layer of uniform temperature and salinity (-1.45 degrees C; 34.25 PSU), values that roughly equal those measured in the ocean in front of the glacier. Moreover, living organisms are found in the thin subglacial water layer. These findings indicate active transport of water and nutrients from the adjacent ocean, meaning that the subshelf environment interacts directly and rapidly with the ocean. (C) 2014 The Authors. Published by Elsevier B.V.
  • Shin Sugiyama, Daiki Sakakibara, Satoshi Matsuno, Satoru Yamaguchi, Sumito Matoba, Teruo Aoki
    ANNALS OF GLACIOLOGY 55 66 25 - 33 2014年 [査読有り][通常論文]
     
    To study the glaciological processes controlling the mass budget of Greenland's peripheral glaciers and ice caps, field measurements were carried out on Qaanaaq ice cap, a 20 km long ice cap in northwestern Greenland. In the summer of 2012, we measured surface melt rate, ice flow velocity and ice thickness along a survey route spanning the ice margin (200 m a.s.l.) to the ice-cap summit (1110 m a.s.l.). Melt rates in the ablation area were clearly influenced by dark materials covering the ice surface, where degree-day factors varied from 5.44 mm w.e. K-1 d(-1) on a clean surface to 8.26 mm w.e. K-1 d(-1) in the dark regions. Ice velocity showed diurnal variations, indicating the presence of surface-meltwater induced basal sliding. Mean ice thickness along the survey route was 120 m, with a maximum thickness of 165m. Ice velocity and temperature fields were computed using a thermomechanically coupled numerical glacier model. Modelled ice temperature, obtained by imposing estimated annual mean air temperature as the surface boundary condition, was substantially lower than implied by the observed ice velocity. This result suggests that the ice dynamics and thermodynamics of the ice cap are significantly influenced by heat transfer from meltwater and changing ice geometry.
  • K. Hara, F. Nakazawa, S. Fujita, K. Fukui, H. Enomoto, S. Sugiyama
    ATMOSPHERIC CHEMISTRY AND PHYSICS 14 18 10211 - 10230 2014年 [査読有り][通常論文]
     
    Measurements of aerosol number concentrations and direct aerosol sampling were conducted on continental Antarctica during the traverse of the Japanese-Swedish joint Antarctic expedition (JASE) from 14 November 2007 until 24 January 2008. Aerosol concentrations in background conditions decreased gradually with latitude in inland regions during the traverse. The lowest aerosol number concentrations were 160 L-1 in D-p > 0.3 mu m, and 0.5 L-1 in Dp > 2 mu m. In contrast, aerosol concentrations reached 3278 L-1 in Dp > 0.3 mu m, and 215 L-1 in Dp > 2 mu m under strong wind conditions. The estimated aerosol mass concentrations were 0.04-5.7 mu gm(-3). Single particle analysis of aerosol particles collected during the JASE traverse was conducted using a scanning electron microscope equipped with an energy dispersive x ray spectrometer. Major aerosol constituents were sulfates in fine mode, and sulfate, sea salts, modified sea salts, and fractionated sea salts in coarse mode. K-rich sulfates, Mg-rich sulfate, Ca-rich sulfates, and minerals were identified as minor aerosol constituents. Horizontal features of Cl/Na ratios imply that sea-salt modification (i.e. Cl loss) occurred on the Antarctic continent during the summer. Most sea-salt particles in the continental region near the coast were modified with acidic sulfur species such as H2SO4 and CH3SO3H. By contrast, acidic species other than the acidic sulfur species (likely HNO3) contributed markedly to sea-salt modification in inland areas during the traverse. Mg-rich sea-salt particles and Mg-free sea-salt particles were present in coarse and fine modes from the coast to inland areas. These sea-salt particles might be associated with sea-salt fractionation on the snow surface of continental Antarctica.
  • Shun Tsutaki, Shin Sugiyama, Daisuke Nishimura, Martin Funk
    Journal of Glaciology 59 215 559 - 570 2013年07月 [査読有り][通常論文]
     
    In 2005 the ongoing retreat of Rhonegletscher, Switzerland, led to the formation of a proglacial lake. To investigate the influence of proglacial lake formation on the dynamics and evolution of glaciers, we measured horizontal flow velocity, vertical ice motion and water levels in boreholes with high spatial resolutions during the summer seasons of 2007-09. Annual flow speeds near the terminus increased by a factor of 2.7 from 2005/06 to 2007/08, and exceeded 20ma-1 in 2009. The velocity increased towards the glacier front, indicating that the ice was thinning under a longitudinally stretching flow regime. Our observations show that the increase in flow speed near the terminus was due to increases in basal motion as a result of ice thinning. During summer 2009, the ice surface at the terminus moved vertically upwards by up to 4.69m as the ice began to float on the lake. The observed ice motion can be explained by the upward bending of marginal ice and the formation of faults that cut through the entire ice thickness. We predict that if the current ice thinning continues, the basal water pressure will exceed the pressure exerted by the ice overburden, and the glacier will progressively disintegrate over an expanding area.
  • Daisuke Nishimura, Shin Sugiyama, Andreas Bauder, Martin Funk
    Arctic, Antarctic, and Alpine Research 45 4 552 - 562 2013年 [査読有り][通常論文]
     
    We have studied changes in the ice-flow velocity and ice thickness in Rhonegletscher, Switzerland, over the period 1874-2006. The flow velocity field and surface elevation were analyzed in the lower half of the glacier using aerial photograph pairs taken in 1970/1971, 1981/1982, 1999/2000, and 2005/2006. We also digitized velocities measured by Mercanton (1916) in 1874-1910 by tracking stones distributed on the glacier. The results showed that the ice-flow velocity and ice straining conditions were strongly influenced by changes in the glacier geometry over the last 100 years. For example, the longitudinal strain rate near the current terminus has changed from tensile to compressive since the retreat of the glacier over a steep bedrock slope to a relatively flat region. The velocity decreased over the studied region from 1981 to 2006, which is in agreement with the ice thinning during the same period. However, the rate of the velocity change was smaller in the post-1990 period, because the effect of the thinning on ice flow speed was partly canceled out by the effect of steepening of the ice surface. The velocity change also implied that the magnitude of basal ice motion was influenced by changing subglacial drainage conditions and proglacial lake formation. Our unique data set contributes to a better understanding of ice dynamics under changing glacier geometry.
  • Shin Sugiyama, Kotaro Fukui, Koji Fujita, Kenta Tone, Satoru Yamaguchi
    ANNALS OF GLACIOLOGY 54 64 157 - 162 2013年 [査読有り][通常論文]
     
    To investigate recent glacier changes in the Himalayan region, we carried out GPS and ground-penetrating radar (GPR) measurements at Yala Glacier, a benchmark glacier in Nepal. Glacier surface elevation and ice thickness were surveyed along a 1.5 km profile from the glacier top to the terminus. Ice flow velocity was measured at five locations by surveying stakes for either 1 year or 4 day periods. Obtained surface elevation and ice velocity were compared with those measured in 1982 and 1996. The mean ice thickness along the radar profile was 36 m in 2009 and the ice has been thinning at rates of -0.69 +/- 0.25 and -0.75 +/- 0.24 m a(-1) during the periods 1982-96 and 1996-2009, respectively. The thinning rate increases down-glacier, reaching a magnitude up to -1.8 m a(-1) near the terminus from 1996 to 2009. The ice velocity has reduced by >70% from 1982 to 2009 in the lower half of the glacier. By assuming a constant driving stress over the glacier, the total ice volume in 2009 was estimated as 0.061 km(3). Our results indicate that Yala Glacier has lost similar to 40% of its ice volume over the last 27 years and that the rate of the mass loss has accelerated over the last decade.
  • Daiki Sakakibara, Shin Sugiyama, Takanobu Sawagaki, Sebastian Marinsek, Pedro Skvarca
    ANNALS OF GLACIOLOGY 54 63 131 - 138 2013年 [査読有り][通常論文]
     
    The Patagonia lcefields are characterized by a large number of outlet glaciers calving into lakes and the ocean. In contrast to the recent intensive research activities on tidewater glaciers in other regions, very few observations have been made on calving glaciers in Patagonia. We analysed satellite images of Glaciar Upsala, the third largest freshwater calving glacier in the Southern Patagonia Icefield, to investigate changes in its front position, ice velocity and surface elevation from 2000 to 2011. Our analyses revealed a clear transition from a relatively stable phase to a rapidly retreating and fast-flowing condition in 2008. The glacier front receded by 2.9 km, and the ice velocity increased by 20-50%, over the 2008-11 period. We also found that the ice surface lowered at a rate of up to 39 m a(-1) from 2006 to 2010. This magnitude and the rate of changes in the glacier front position, ice velocity and surface elevation are greater than previously reported for Glaciar Upsala, and comparable to recent observations of large tidewater glaciers in Greenland. Our data illustrate details of a rapidly retreating calving glacier in Patagonia that have been scarcely reported despite their importance to the mass budget of the Patagonia Icefields.
  • S. Fujita, P. Holmlund, K. Matsuoka, H. Enomoto, K. Fukui, F. Nakazawa, S. Sugiyama, S. Surdyk
    CRYOSPHERE 6 5 1203 - 1219 2012年 [査読有り][通常論文]
     
    In order to better understand the spatial distribution of subglacial environments, ground-based radar profiling data were analyzed for a total distance of similar to 3300 km across Dronning Maud Land, East Antarctica. The relationship between geometrically corrected bed returned power [Pc bed] dB in decibels and ice thickness H was examined. When H is smaller than a critical value that varies according to location, [P-bed(c)](dB) tends to decrease relatively smoothly with increasing H, which is explicable primarily by the cumulative effect of dielectric attenuation within the ice. However, at locations where H is larger than the critical H values, anomalous increases and fluctuations in [P-bed(c)](dB) were observed, regardless of the choice of radar frequency or radar-pulse width. In addition, the amplitude of the fluctuations often range 10 similar to 20 dB. We argue that the anomalous increases are caused by higher bed reflectivity associated with the existence of subglacial water. We used these features to delineate frozen and temperate beds. Approximately two-thirds of the investigated area was found to have a temperate bed. The beds of the inland part of the ice sheet tend to be temperate, with the exception of subglacial high mountains. In contrast, the beds of coastal areas tend to be frozen, with the exception of fast-flowing ice on the subglacial lowland or troughs. We argue that this new analytical method can be applied to other regions.
  • Shin Sugiyama, Hiroyuki Enomoto, Shuji Fujita, Kotaro Fukui, Fumio Nakazawa, Per Holmlund, Sylviane Surdyk
    JOURNAL OF GLACIOLOGY 58 209 529 - 539 2012年 [査読有り][通常論文]
     
    During the Japanese-Swedish Antarctic traverse expedition of 2007/08, we measured the surface snow density at 46 locations along the 2800 km long route from Syowa station to Wasa station in East Antarctica. The mean snow density for the upper 1 (or 0.5) m layer varied from 333 to 439 kg m(-3) over a region spanning an elevation range of 365-3800 m a.s.l. The density variations were associated with the elevation of the sampling sites; the density decreased as the elevation increased, moving from the coastal region inland. However, the density was relatively insensitive to the change in elevation along the ridge on the Antarctic plateau between Dome F and Kohnen stations. Because surface wind is weak in this region, irrespective of elevation, the wind speed was suggested to play a key role in the near-surface densification. The results of multiple regression performed on the density using meteorological variables were significantly improved by the inclusion of wind speed as a predictor. The regression analysis yielded a linear dependence between the density and the wind speed, with a coefficient of 13.5 kg m(-3) (m s(-1))(-1). This relationship is nearly three times stronger than a value previously computed from a dataset available in Antarctica. Our data indicate that the wind speed is more important to estimates of the surface snow density in Antarctica than has been previously assumed.
  • Fujita, S, Enomoto, H, Fukui, K, Iizuka, Y, Motoyama, H, Nakazawa, F, Sugiyama, S, Surdyk, S
    The Cryosphere Discussions 6 2 1205-1267  2012年 [査読無し][通常論文]
     
    Abstract. The initial stage of postdepositional metamorphism in polar firn was investigated at sites located under spatial variations of accumulation rate and wind speed along the East Antarctic ice divide near Dome Fuji. A better understanding of this process is important for interpreting local insolation proxies used for astronomical dating of deep ice cores. Three 2–4 m deep pits were excavated and physical properties, including density ρ, grain size D, reflectance R of near infrared light and microwave dielectric anisotropy Δε, were investigated at high spatial resolution. We found that Δε ranges between 0.028 and 0.067 and that such high values occur in the surface ~0.1 m. In addition, short scale variations of ρ are correlated with those of Δε, and inversely correlated with those of D, confirming contrasting development of initially higher density layers and initially lower density layers. Moreover, postdepositional metamorphism makes these contrasts more distinct with increasing depths. Both the contrasts and Δε for given values of ρ are higher under lower accumulation rate conditions and under less windy conditions. Insolation efficiently causes evolution of strata of firn at the ice sheet surface under such conditions. Under more windy conditions, the strata contain more wind-driven hard layers with higher ρ and Δε and thus have larger fluctuations of ρ and Δε. We suggest that the initial variability of ρ at the surface and the duration of exposure to diurnal and seasonal temperature gradients play sequential roles in determining the physical/mechanical properties of firn, which is retained throughout the densification process.
  • Shin Sugiyama, Pedro Skvarca, Nozomu Naito, Hiroyuki Enomoto, Shun Tsutaki, Kenta Tone, Sebastian Marinsek, Masamu Aniya
    NATURE GEOSCIENCE 4 9 597 - 600 2011年09月 [査読有り][通常論文]
     
    Ice flow acceleration has played a crucial role in the rapid retreat of calving glaciers in Alaska(1,2), Greenland and Antarctica(3,4). Glaciers that calve in water flow much faster than those that terminate on land, as a result of enhanced basal ice motion where basal water pressure is high(5). However, a scarcity of subglacial observations in calving glaciers limits a mechanistic understanding. Here we present high-frequency measurements of ice speed and basal water pressures from Glaciar Perito Moreno, a fast-flowing calving glacier in Patagonia. We measured water pressure in boreholes drilled at a site where the glacier is 515 +/- 5m thick, and where more than 60% of the ice is below the level of proglacial lakes. We found that the mean basal water pressure was about 95% of the pressure imposed by the weight of the overlying ice. Moreover, changes in basal water pressure by a few per cent drove nearly 40% of the variations in ice flow speed. The ice speed was strongly correlated to air temperature, suggesting that glacier motion was modulated by water pressure changes as meltwater entered the system. We conclude that basal water pressure in calving glaciers is important for glacier dynamics, and closely connected to climate conditions.
  • Masamu Aniya, Pedro Skvarca, Shin Sugiyama, Tatsuto Aoki, Takane Matsumoto, Ryo Anma, Nozomu Naito, Hiroyuki Enomoto, Kazuaki Hori, Sebastián Marinsek, Keiko Konya, Takayuki Nuimura, Shun Tsutaki, Kenta Tone, Gonzalo Barcaza
    Bulletin of Glaciological Research 29 1 - 17 2011年 [査読有り][通常論文]
     
    The Glaciological Research Project in Patagonia (GRPP) 2006-2009 was carried out with several objectives at Glaciar Perito Moreno of the Hielo Patagonico Sur (HPS), in the area of the Hielo Patagonico Norte (HPN) and along the Pacific coast. At Glaciar Perito Moreno, hot water drilling was carried out at about 5 km upstream from the terminus, reaching the glacier bottom at ca. 515 m, in order to monitor subglacial water pressure. Good positive correlations among air temperature, subglacial water pressure and glacier flow speed were found. Based on 14C dating of tree and organic samples, it is proposed that Glaciar Perito Moreno made two Little Ice Age (LIA) advances at AD1600-1700 and ca. 130-100 y BP (AD1820-50). Fan deltas located at the mouth of big rivers around Lago General Carrera (Buenos Aires) and Lago Cochrane (Pueyrredon), in the area east of the HPN, were investigated to elucidate their development. The variations of 21 outlet glaciers of the HPN elucidated from aerial surveys for 2004/ 05-2008/09 revealed an areal loss of 8.67 km2 in four years. A general slowing down of retreats was observed with a few exceptions. Meteorological measurements at Glaciar Exploradores of the HPN from 2005 to 2009 indicate that air temperature ranged from 17.4°C to - 10.5°C. The total annual precipitation was about 3000 mm. Glacier surface melt was observed at two spots. Sediment and water discharges from the glacier showed that while water discharge fluctuated a lot, suspended sediment concentration was rather stable in summer. A single channel seismic profiling during the JAMSTEC MR08-06 cruise identified a probable submerged moraine formed before the last glacial maximum (LGM) in the Golfo de Penas, south of Taitao Peninsula. Piston coring along the Chilean coast further indicates that ice-rafted debris recorded the LGM and earlier Late Pleistocene events of the glacial advance. © Japanese Society of Snow and Ice.
  • S. Fujita, P. Holmlund, I. Andersson, I. Brown, H. Enomoto, Y. Fujii, K. Fujita, K. Fukui, T. Furukawa, M. Hansson, K. Hara, Y. Hoshina, M. Igarashi, Y. Iizuka, S. Imura, S. Ingvander, T. Karlin, H. Motoyama, F. Nakazawa, H. Oerter, L. E. Sjoberg, S. Sugiyama, S. Surdyk, J. Strom, R. Uemura, F. Wilhelms
    CRYOSPHERE 5 4 1057 - 1081 2011年 [査読有り][通常論文]
     
    To better understand the spatio-temporal variability of the glaciological environment in Dronning Maud Land (DML), East Antarctica, a 2800-km-long Japanese-Swedish traverse was carried out. The route includes ice divides between two ice-coring sites at Dome Fuji and EPICA DML. We determined the surface mass balance (SMB) averaged over various time scales in the late Holocene based on studies of snow pits and firn cores, in addition to radar data. We find that the large-scale distribution of the SMB depends on the surface elevation and continentality, and that the SMB differs between the windward and leeward sides of ice divides for strong-wind events. We suggest that the SMB is highly influenced by interactions between the large-scale surface topography of ice divides and the wind field of strong-wind events that are often associated with high-precipitation events. Local variations in the SMB are governed by the local surface topography, which is influenced by the bedrock topography. In the eastern part of DML, the accumulation rate in the second half of the 20th century is found to be higher by similar to 15% than averages over longer periods of 722 a or 7.9 ka before AD 2008. A similar increasing trend has been reported for many inland plateau sites in Antarctica with the exception of several sites on the leeward side of the ice divides.
  • P. Dalban Canassy, A. Bauder, M. Dost, R. Faeh, M. Funk, S. Margreth, B. Mueller, S. Sugiyama
    NATURAL HAZARDS AND EARTH SYSTEM SCIENCES 11 8 2149 - 2162 2011年 [査読有り][通常論文]
     
    The details and the consequences of the recent retreat of Triftgletscher (Gadmertal, Bernese Alps, Switzerland) have been investigated. Geodetic volume changes indicate a strong decrease since 1929 while the position of the terminus remained practically unchanged until 1990. The role played by calving in the tongue retreat running from 2000 to 2006 is confirmed by means of a mass balance model including a calving criterion. Results show that without calving, it would have taken two years longer for the lake to form than has been observed. The consequences of the ensuing tongue destabilization are surveyed, first with an ice avalanche model and second with a hydraulic study of the potential impulse wave triggered by the impact of the falling ice mass in the lake. Results point out that ice avalanches with volumes greater that 1.10(6) m(3) will flow into the lake and that in the worst scenario, a discharge of 400 m(3) s(-1) is expected to reach the endangered area in Gadmertal 11 min after the break-off. In order to detect surface motion precursors to such ice avalanches, a photographic monitoring system was installed. The results indicate seasonal variations with peak velocity in summer and no significant change during the other months. Spectacular velocity increases were not observed so far.
  • Shun Tsutaki, Daisuke Nishimura, Takeshi Yoshizawa, Shin Sugiyama
    ANNALS OF GLACIOLOGY 52 58 31 - 36 2011年 [査読有り][通常論文]
     
    To investigate the impact of proglacial lake formation on the dynamics and evolution of glaciers, we measured the ice motion of the terminal part of Rhonegletscher, Switzerland, where a lake formed in 2005. In 2009, the flow velocity near the terminus was >20 m a(-1). One of the survey stakes tripled its velocity between 2006 and 2007. Since the lake water pressure was consistently close to the ice overburden pressure, it is likely that the high subglacial water pressure enhanced the basal ice motion. The estimated flow velocity due to ice shearing was negligibly small; almost 100% of the horizontal velocity near the terminus was caused by basal sliding. The longitudinal strain rate was large, 0.064 a(-1), indicating that much of the glacier thinning was due to ice dynamics. The region of ice flotation adjacent to the lake expanded between 2008 and 2009 as a result of glacier thinning. Accordingly, a huge uplift of the surface was observed in 2009. It is clear from the vertical ice motion as well as visual observations that the marginal part of the glacier began to float. The ice-thinning rate in the studied area from 2008 to 2009 was 3.4 m a(-1), larger than previous estimates.
  • Shin Sugiyama, Takeshi Yoshizawa, Matthias Huss, Shun Tsutaki, Daisuke Nishimura
    ANNALS OF GLACIOLOGY 52 58 1 - 8 2011年 [査読有り][通常論文]
     
    The spatial pattern of glacier surface melt was measured with a resolution of 20-100 m within a region extending 1 km up-glacier from the terminus of Rhonegletscher, Switzerland. The melt rate was monitored from 6 July to 6 September 2009 using 44 ablation stakes. We also measured the surface albedo near the stakes to investigate the importance of this parameter for the melt-rate distribution. The melt rate varied from 32.8 to 71.9 mm w.e. d(-1) in the study area. Our measurements suggest that the spatial variation of the melt rate can be explained by (1) shading of the ice surface by neighbouring mountains, (2) surface albedo and (3) effects of microclimate (e.g. radiation from side-walls) on the surface energy balance. The observed melt-rate distribution was compared to the results of a temperature-index melt model, which takes into account shading of direct solar illumination but not the other two effects. The model reproduces some important features of the field data, but its spatial variations are generally less than the measured values. Our study shows the importance of albedo and other local conditions in the accurate estimation of the small-scale melt-rate distribution.
  • Takehiro Fukuda, Shin Sugiyama, Sumito Matoba, Takayuki Shiraiwa
    ANNALS OF GLACIOLOGY 52 58 138 - 142 2011年 [査読有り][通常論文]
     
    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.
  • P. -F. Roux, F. Walter, P. Riesen, S. Sugiyama, M. Funk
    JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE 115 F3 F03014  2010年07月 [査読有り][通常論文]
     
    During the 2004 outburst flood of Gornersee, Switzerland, we observed surface microseismic activity (so-called icequakes) near the glacier-dammed lake on Gornergletscher. Using surface waves, we located near-surface tensile fracturing events by inverting time delays using a quasi-Newton scheme. We located 8520 near-surface events with uncertainties of less than 10 m. Seismic activity increased during the lake drainage, and the icequake epicenters migrated downglacier. Furthermore, we identified events whose fault plane orientations are nearly perpendicular to the local pattern of surface crevassing. These observations can be explained by the rotation of principal strains at the glacier surface deduced from local ice flow measurement which occurred during the flotation of the ice dam at the onset of the lake drainage. In general, we suggest that our technique is a useful tool to locate large data sets of microseismic events and can be used to monitor the temporal evolution of fracture processes and their dependence on glacier flow and glacier hydrology.
  • S. Sugiyama, A. Bauder, P. Riesen, M. Funk
    JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE 115 F3 F03010  2010年07月 [査読有り][通常論文]
     
    High frequency ice flow measurements during speed-up events in Gornergletscher, Switzerland, revealed intriguing ice motion which has never been reported in detail before. During the summer 2005, more than a 100% flow speed increase was observed three times at four GPS stations installed across Gornergletscher. The speed-ups were accompanied by a decimeter scale surface uplift. Two of the events were triggered by intensive surface melt and rainfall, while the third one was due to the outburst of Gornersee, a glacier-dammed lake located 2 km upglacier. An interesting observation was ice motion deviating toward the side margins during the events. As the glacier accelerated, a transverse (cross glacier) velocity component was generated, turning the flow direction away from the central flow line toward the margins. When the glacier decelerated, the transverse velocity component reversed so that the ice flowed back to the azimuth of the initial flow direction. In the most significant case, the trajectory of the survey stake deviated from the original track by 0.2 m in the transverse direction. We hypothesize that the observed lateral ice motion was caused by locally elevated subglacial water pressure. When the ice sole decoupled from the bed at a part of the glacier, a point source of vertical displacement was transmitted to the surface through viscous ice. This caused the transverse as well as vertical surface motion, as observed in ground motion during magma intrusion. The hypothesis was tested with a two-dimensional ice flow model applied to the transverse glacier cross section. The model confirmed that the surface ice would move toward the margins as observed in Gornergletscher, if subglacial water pressure exceeded the ice overburden pressure over a limited part of the bed.
  • Sugiyama Shin, Enomoto Hiroyuki, Fujita Shuji, Fukui Kotaro, Nakazawa Fumio, Holmlund Per
    Annals of Glaciology 51 55 9 - 15 International Glaciological Society 2010年 [査読有り]
     
    As a joint contribution of Japan and Sweden to the International Polar Year 2007-09, a field expedition between Syowa and Wasa stations in East Antarctica was carried out in the 2007/08 austral summer season. Along the 2800 km long expedition route, the dielectric permittivity of the upper 1 m snow layer was measured at intervals of approximately 50 km using a snow fork, a parallel-wire transmission-line resonator. More than 2000 measurements were performed under carefully calibrated conditions, mostly in the interior of Antarctica. The permittivity ε′ was a function of snow density as in previous studies on dry snow, but the values were significantly smaller than those reported before. In the light of the dielectric mixture theory, the relatively smaller ε′ obtained in this study can be attributed to the snow structures characteristic in the studied region. Our data suggest that the permittivity of snow in the Antarctic interior is significantly affected by weak bonding between snow grains, which is due to depth-hoar formation in the extremely low-temperature conditions.
  • Patrick Riesen, Shin Sugiyama, Martin Funk
    JOURNAL OF GLACIOLOGY 56 196 278 - 286 2010年 [査読無し][通常論文]
     
    Gornergletscher, Switzerland, is located adjacent to the marginal lake Gornersee, which periodically drains. We measured glacier ice-flow velocities during two drainage events of the lake, in 2004 and 2006. The common feature of these events was that, during both, Gornersee filled to its maximum level and then overflowed. The events differed in that in 2004 Gornersee rapidly drained via a sudden subglacial connection, whereas in 2006 the lake water continued to overflow and slowly discharged into a nearby moulin. We analysed the changes in ice-flow velocities in the vicinity of Gornersee during the two drainage events, using a three-dimensional ice-flow model which is able to (1) simulate locally variable enhanced basal motion of the ice and (2) account for the load and release of water pressure exerted on the ice margin. We demonstrate that the key features of the observed flow changes can be reproduced adequately in the numerical model by considering these two effects as the main mechanisms. We interpret the 2006 flow changes to be dominated by the release of lake water pressure acting on the ice during the lake drainage. The 2004 ice-flow changes can be explained by enhanced basal motion, and the impact of the lake water pressure provides certain clues to some observations insufficiently explained by enhanced basal motion.
  • Shin Sugiyama, Kenta Tone, Kunio Shinbori, Sebastian Marinsek, Pedro Skvarca, Nozomu Naito, Hiroyuki Enomoto, Masamu Aniya
    Bulletin of Glaciological Research 28 27 - 32 2010年 [査読有り][通常論文]
     
    Glaciar Perito Moreno is one of the major freshwater calving glaciers in the Southern Patagonia Icefield. Its fast-flowing characteristic is probably due to high water pressure at the glacier bed, however, subglacial conditions have never been observed in Patagonia until our recent undertaking. To investigate the role of subglacial water pressure in the calving glacier dynamics, we performed hot-water drilling at Glaciar Perito Moreno from February to March 2010. This study represents the first attempt ever at hot-water glacier drilling in Patagonia. Two boreholes were drilled to the bed at 4.7 km upglacier from the terminus, where the ice was revealed to be 515±5m thick and the bed located at about mbelow the proglacial lake level. The water levels in the boreholes were > 100m above the lake level, which indicates that more than 90% of the ice overburden pressure was balanced out by the subglacial water pressure. Water in the boreholes had drained away before the drilling reached the bed, suggesting the existence of an englacial drainage system. These results provide crucial information for understanding the hydraulic and hydrological conditions of calving glaciers. In order to drill a 500 m deep glacier, an existing hot-water drilling system was adapted by increasing the number of high-pressure hot-water machines. The drilling operation at Glaciar Perito Moreno confirmed the system's capacity to drill a 500-m-deep borehole at a rate of 50 m h-1 with fuel consumption rates of 15.71 h-1 for diesel and 3.91 h-1 for petrol. © 2010, THE JAPANESE SOCIETY OF SNOW AND ICE. All rights reserved.
  • Hiroaki Ota, Takeshi Hashimoto, Yohei Nagakura, Shuhei Takamura, Akira Fukuda, Masamu Aniya, Nozomu Naito, Hiroyuki Enomoto, Shin Sugiyama, Pedro Skvarca
    International Conference on Humans and Computers, HC '10, Aizu-Wakamatsu, Fukushima-ken, Japan, December 6-10, 2010 195 - 202 University of Aizu Press / ACM 2010年 [査読有り][通常論文]
  • Tsutaki, S, S. Sugiyama
    Bulletin of Glaciological Research 27 7 - 14 2009年 [査読有り][通常論文]
  • 杉山 慎, 津滝 俊, 内藤 望, 榎本 浩之, Skvarca Pedro
    雪氷研究大会講演要旨集 2009 166 - 166 公益社団法人 日本雪氷学会/日本雪工学会 2009年
  • 福田 武博, 杉山 慎, 白岩 孝行, 的場 澄人
    雪氷研究大会講演要旨集 2009 167 - 167 公益社団法人 日本雪氷学会/日本雪工学会 2009年
  • 榎本 浩之, 内藤 望, 杉山 慎, 津滝 俊, 福田 明, 安仁屋 政武, 磯野 真滋, Skvarca Pedro
    雪氷研究大会講演要旨集 2009 140 - 140 公益社団法人 日本雪氷学会/日本雪工学会 2009年
  • 津滝 俊, 杉山 慎
    雪氷研究大会講演要旨集 2009 141 - 141 公益社団法人 日本雪氷学会/日本雪工学会 2009年
  • 西村 大輔, 津滝 俊, 杉山 慎
    雪氷研究大会講演要旨集 2009 165 - 165 公益社団法人 日本雪氷学会/日本雪工学会 2009年
  • S. Sugiyama, A. Bauder, M. Huss, P. Riesen, M. Funk
    JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE 113 F4 F04019  2008年12月 [査読有り][通常論文]
     
    To investigate the triggering and the drainage mechanisms of a glacier-dammed lake outburst, we conducted high-frequency measurements of the ice surface motion in the vicinity of Gornersee, an ice marginal lake on Gornergletscher, Switzerland. During the outburst event in July 2004, the ice surface within a distance of 400 m from the lakeshore moved vertically upward by up to 0.1 m. This vertical surface motion cannot be explained by vertical straining of ice which was measured in one of the boreholes; therefore, we suggest the separation of the glacier sole from the bed was caused by subglacially drained lake water. Our observation indicates that the lake water drained as a sheet-like flow through the space created by the basal separation. The upward surface motion was greater in the region where the ice flotation level was exceeded by the lake level, implying that the ice barrier was breached when the lake water hydraulically connected to the bed and lifted up the glacier. In addition to the centimeter-scale vertical ice motion, three survey stakes located within 100 m from the lake showed extraordinarily large vertical displacement of 0.5-3.0 m associated with abrupt changes in horizontal flow direction. A plausible interpretation is that the marginal ice wedge bent upward because of the buoyancy force generated by the drained water. Such bending is possible if subglacial and englacial fractures formed at about 200 m from the glacier margin and acted as a hinge. The newly formed and preexisting englacial fractures probably took the role of inducing englacial water drainage which preceded the outburst.
  • F. Pattyn, L. Perichon, A. Aschwanden, B. Breuer, B. de Smedt, O. Gagliardini, G. H. Gudmundsson, R. C. A. Hindmarsh, A. Hubbard, J. V. Johnson, T. Kleiner, Y. Konovalov, C. Martin, A. J. Payne, D. Pollard, S. Price, M. Rückamp, F. Saito, O. Souček, S. Sugiyama, T. Zwinger
    The Cryosphere 2 2 95 - 108 2008年08月26日 [査読有り][通常論文]
     
    Abstract. We present the results of the first ice sheet model intercomparison project for higher-order and full-Stokes ice sheet models. These models are compared and verified in a series of six experiments of which one has an analytical solution obtained from a perturbation analysis. The experiments are applied to both 2-D and 3-D geometries; five experiments are steady-state diagnostic, and one has a time-dependent prognostic solution. All participating models give results that are in close agreement. A clear distinction can be made between higher-order models and those that solve the full system of equations. The full-Stokes models show a much smaller spread, hence are in better agreement with one another and with the analytical solution.
  • Sugiyama, S, S. Tsutaki, D. Nishimura, H. Blatter, A. Bauder, M. Funk
    Bulletin of Glaciological Research 26 41 - 47 2008年 [査読有り][通常論文]
  • Matthias Huss, Shin Sugiyama, Andreas Bauder, Martin Funk
    ARCTIC ANTARCTIC AND ALPINE RESEARCH 39 3 422 - 431 2007年08月 [査読有り][通常論文]
     
    The future evolution of Unteraargletscher, a large valley glacier in the Swiss Alps, is assessed for the period 2005 to 2050 using a flowline model. Detailed measurements of surface velocity from the last decade allow us to relate ice flux to glacier thickness and width. Mass balance is calculated using a distributed temperature-index model calibrated with ice volume changes derived independently from comparison of repeated digital elevation models. The model was validated for the period 1961 to 2005 and showed good agreement between the simulated and observed evolution of surface geometry. Regional climate scenarios with seasonal resolution were used to investigate the anticipated response of Unteraargletscher to future climate changes. Three mass balance scenarios were defined, corresponding to 2.5%, 50%, and 97.5% quantiles of a statistical analysis of 16 different climate model results. We present a forecast of the future extent of Unteraargletscher in the next five decades and analyze relevant parameters with respect to the past. The model predicts a retreat of the glacier terminus of 800-1025 in by 2035, and of 1250-2300 in by 2050. The debris coverage of the glacier tongue reduces the retreat rate by a factor of three. The thinning, rate increased by 50-183% by 2050 depending on the scenario applied, compared to the period 1997 to 2005.
  • Sugiyama Shin, Bauder Andreas, Zahno Conradin, Funk Martin
    Annals of Glaciology 46 268 - 274 International Glaciological Society 2007年 [査読有り][通常論文]
     
    To study the past and future evolution of Rhonegletscher, Switzerland, a flowline model was developed to include valley shape effects more accurately than conventional flowband models. In the model, the ice flux at a gridpoint was computed by a two-dimensional ice-flow model applied to the valley cross-section. The results suggested the underestimation of the accumulation area, which seems to be a general problem of flowline modelling arising from the model's one-dimensional nature. The corrected mass balance was coupled with the equilibrium-line altitude (ELA) change, which was reconstructed for the period 1878–2003 from temperature and precipitation records, to run the model for the past 125 years. The model satisfactorily reproduced both changes in the terminus position and the total ice volume derived from digital elevation models of the surface obtained by analyses of old maps and aerial photographs. This showed the model's potential to simulate glacier evolution when an accurate mass balance could be determined. The future evolution of Rhonegletscher was evaluated with three mass-balance conditions: the mean for the period 1994–2003, and the most negative (2003) and positive (1978) mass-balance values for the past 50 years. The model predicted volume changes of –18%, –58% and +38% after 50 years for the three conditions, respectively.
  • Shin Sugiyama, Andreas Bauder, Patrik Weiss, Martin Funk
    JOURNAL OF GLACIOLOGY 53 181 172 - 180 2007年 [査読有り][通常論文]
     
    During the outburst flood of a glacier-dammed lake on Gornergletscher, Switzerland, in July 2004, the drained lake water triggered anomalous glacier motion. At the onset of the outburst, the ice-flow direction in the vicinity of the lake became closer to the central flowline. When the lake discharge magnitude decreased, the flow direction altered such that the ice moved back to the azimuth of the initial motion. At one of the survey points, where the ice flows parallel to the central flowline, the ice accelerated along the pre-event flow direction followed by a 180 degrees backward motion that lasted over 2 days. These observations indicate the impact of the lake outburst on the subglacial and englacial stress conditions; however, the reversal in the flow direction is difficult to explain by drawing on our current understanding of glacier mechanics. The timing and the timescale of the flow-direction changes suggest that the elastic glacier motion and its rebound played a role under the rapidly changing stress conditions, but the Young's modulus of ice is too large to cause the observed ice motion. Other processes, including basal separation and subglacial sediment deformation, are discussed as possible mechanisms for the reversal of the ice motion.
  • 津滝 俊, 杉山 慎
    日本雪氷学会全国大会講演予稿集 2007 4 - 4 公益社団法人 日本雪氷学会 2007年
  • Sugiyama, S
    Glacier Science and Environmental Change 345 - 347 2006年 [査読有り][通常論文]
  • Sugiyama Shin, Naruse Renji, Murav'yev Yaroslav D.
    Annals of Glaciology 40 232 - 236 International Glaciological Society 2005年 [査読有り][通常論文]
     
    To investigate short-term flow-pattern variations of a temperate glacier, longitudinal surface strain was measured with a wire strainmeter in the ablation area of Koryto glacier, Kamchatka, Russia. Strain-rate anomalies were observed in late summer 2000 that were triggered by a water overflow from a moulin near the measurement site followed by the drainage of accumulated water. The strain event started with (compressive) strain rates of >–10–3 d–1 lasting for 6 hours, which then became tensile. Similar strain-rate variations were observed again on the next day. During the event, basal sliding speed measured at the margin in the lower reach of the glacier fluctuated by about ±50% of the daily mean. Smaller and larger sliding speeds corresponded to the compressive and tensile surface strains, respectively. These measurements suggest that the storage and sudden drainage of water caused spatially non-uniform water-pressure fluctuations along the glacier, changing the sliding regime over short time periods.
  • Seddik H, S. Sugiyama, R. Naruse
    Bulletin of Glaciological Research 22 75 - 79 2005年 [査読有り][通常論文]
  • S Sugiyama, GH Gudmundsson
    JOURNAL OF GLACIOLOGY 50 170 353 - 362 2004年 [査読有り][通常論文]
     
    Short-term variations in horizontal and vertical surface motion were studied with high temporal resolution during the ablation season in Lauteraargletscher, Bernese Alps, Switzerland. Horizontal surface flow speed oscillated diurnally, showing a correlation with the water level in a borehole. Flow speed increased as a function of the water level, with an asymptote at the ice overburden level. This observation implied that the flow variations were principally controlled by the local water pressure which enhanced basal motions. Detailed examination of the diurnal variations, however, showed that the speed was larger when the pressure was increasing than when it was decreasing. Greater speed with increasing pressure was interpreted by subglacial watercavity opening and/or longitudinal stress coupling with the upper reaches of the glacier. Upward surface movements were observed when the glacier flow speed increased. Simultaneous measurement of internal vertical strain in a borehole showed that the uplift had two different sources: vertical straining of ice and volume increase of subglacial water cavities. The vertical surface movement was largely affected by the vertical strain, and the uplift events could not be simply attributed to cavity opening.
  • S Sugiyama, GH Gudmundsson, J Helbing
    ANNALS OF GLACIOLOGY, VOL 37 37 49 - 54 2003年 [査読有り][通常論文]
     
    The effects of spatial and temporal variations in basal lubrication on the englacial strain rate and surface velocity distribution are investigated with a numerical ice-flow model. General aspects of the solutions are compared to measurements made on Lauteraargletscher, Switzerland, in 2001, that showed diurnal fluctuations in both surface velocity and englacial vertical strain. We find that spatial gradients in basal lubrication can set up variations in the deviatoric stress field that increases with distance to the bed and has a maximum value near the glacier surface. This stress field produces a significant strain rate near the surface. The temporal evolution of a slippery zone is identified as a possible cause of the observed diurnal variations in the vertical strain rate. Although general aspects of the measurements can be explained in this way, the calculated vertical strain rates are too small, suggesting that the modeled effective viscosity values using Glen's flow law are too large near the surface.
  • S Yamaguchi, R Naruse, S Sugiyama, T Matsumoto, YD Murav'yev
    JOURNAL OF GLACIOLOGY 49 165 173 - 178 2003年 [査読有り][通常論文]
     
    Ice-flow velocities were measured at Koryto glacier on Kamchatka Peninsula, Russia, during a 37 day period in the middle of the 2000 melt season. Six survey points from the upper to the lower reaches of the glacier exhibited daily fluctuations in surface horizontal speed with major peaks that appeared at all points. We argue that basal motion is the major cause of flow on Koryto glacier. Downward vertical velocities measured over most of the glacier during the survey period are likely due to shrinking of englacial and subglacial cavities. This result may imply that a large amount of water is deposited in the early summer. Since 1960, Koryto glacier has retreated by 450 m and this retreat has accelerated following a decrease in winter precipitation after the mid 1970s. The glacier has thinned by 10-50 m during the last 40 years.
  • Influence of surface debris on summer ablation in Unteraar- and Lauteraargletscher, Switzerland
    Sugiyama, S
    Bulletin of Glaciological Research 20 41 - 47 2003年 [査読有り][通常論文]
  • Sugiyama Shin, Gudmundsson G. Hilmar
    Geophysical Research Letters 30 2 American Geophysical Union 2003年01月 [査読有り][通常論文]
     
    During a period of diurnal fluctuations in glacial flows speed, vertical strain wasmeasured with sub-daily temporal resolution on Unteraargletscher, Switzerland. Mean verticalstrain in boreholes up to 300-m deep out of 400-m-thick ice was found to fluctuate diurnally.Vertical strain rates were extensile in the daytime and compressive at night, with a magnitude ofup to 10-3 day-1. Horizontal surface strain was observed to fluctuate in a manner consistent withthe vertical deformation. Diurnal surface flow speed variations correlated well with basal waterpressures suggesting a basal control on temporal flow variations. Nevertheless, the strain ratemeasurements indicated that changes in surface flow speed is affected by internal icedeformation and not a direct measure of local basal motion. Basal conditions in the surroundingneighborhood and their temporal variations take important role in short-term glacial flowfluctuations.
  • S Sugiyama, M Togaya
    JOURNAL OF THE AMERICAN CERAMIC SOCIETY 84 12 3013 - 3016 2001年12月 [査読有り][通常論文]
     
    The phase relationship between 3C- and 6H-SiC is investigated in the pressure range 2.5-6.5 GPa and the temperature range 400 degrees -2500 degreesC, by analyzing recovered samples, using X-ray diffractometry and Raman-scattering techniques. The phased transition from 3C- to 6H-SiC occurs at 2200 degreesC and 2.5 GPa. In the pressure range >4.5 GPa, 6H-SiC transforms to 3C-SiC at 2500 degreesC, via an intermediate state, as indicated by broadening peaks in the X-ray diffraction profile. Thermodynamically, 3C-SiC appears to be the low-temperature stable form, and the temperature of transition to 611-SiC, which is stable at high temperature, appears to increase with pressure.
  • Motohiro Togaya, Shin Sugiyama
    Review of High Pressure Science and Technology/Koatsuryoku No Kagaku To Gijutsu 7 1037 - 1039 1998年 [査読有り][通常論文]
     
    The melting behavior of β -SiC with diamond structure was investigated under high pressures up to about 10 GPa using a flash-heating device. The peritectic temperature, at which the SiC decomposes into two phases of carbon saturated liquid Si and solid carbon (graphite) by a peritectic reaction, increases with pressure and the formation temperature of one liquid phase (l-SiC) also tends to increase with pressure. The solubility of carbon in liquid Si reach 50% at about 10 GPa and β -SiC melts directly into l-SiC. © 1998, The Japan Society of High Pressure Science and Technology. All rights reserved.
  • M TOGAYA, S SUGIYAMA, E MIZUHARA
    HIGH-PRESSURE SCIENCE AND TECHNOLOGY - 1993, PTS 1 AND 2 255 - 258 1994年 [査読有り][通常論文]

書籍

  • 南極の氷に何が起きているか -気候変動と氷床の科学-
    杉山慎 (担当:単著)
    中央公論新社 2021年11月
  • 低温環境の科学事典
    河村公隆 (担当:分担執筆)
    朝倉書店 2016年07月
  • 低温科学便覧
    北海道大学低温科学研究所編 (担当:分担執筆範囲:第5章氷河)
    丸善出版 2015年10月
  • 地球惑星科学入門
    在田一則, 竹下徹, 見延庄士郎, 渡部重十編著 (担当:分担執筆範囲:第27章氷河と氷河時代)
    北海道大学出版会 2010年
  • なぞの宝庫・南極大陸 100万年前の地球を読む
    飯塚芳徳, 澤柿教伸, 杉山慎, 的場澄人 
    技術評論社 2008年

講演・口頭発表等

  • Subglacial discharge controls seasonal variations in the thermal structure of a glacial lake in Patagonia  [通常講演]
    Shin Sugiyama, Masahiro Minowa, Yasushi Fukamachi, Shuntaro Hata, Yoshihiro Yamamoto, Tobias Sauter, Christoph Schneider, Marius Schaefer
    IGS (International Glaciological Society) Symposium on Maritime Glaciers in Juneau, Alaska 2022年06月 口頭発表(一般)
  • Shin Sugiyama, Ken Kondo, Masahiro Minowa
    JpGU 2022 (Japan Geoscience Union Meeting) 2022年05月 口頭発表(一般)
  • 杉山慎, 近藤研, 箕輪昌紘
    雪氷学会北海道支部研究発表会 2022年05月 口頭発表(一般)
  • パタゴニア・グレイ氷河前縁湖における水温と流速の季節変動  [通常講演]
    杉山慎, 箕輪昌紘, 深町康, 波多俊太郎, 山本淳博, サウタ―・トビアス, シュナイダー・クリストフ, シェーファー・マリウス
    雪氷研究大会(千葉・オンライン) 2021年09月 口頭発表(一般)
  • Greenland in a warming climate -Rapid environmental change and its impact on society-  [招待講演]
    Shin Sugiyama
    ASM3 (3rd Arctic Science Ministerial) 2021年05月 口頭発表(基調)
  • Shin Sugiyama
    International Glaciological Society Global Seminar Series 2020年12月 公開講演,セミナー,チュートリアル,講習,講義等
  • Shin Sugiyama, Hiroki Takakura, Akihisa Konno
    The 11th Symposium on Polar Science 2020年12月 口頭発表(招待・特別)
  • 杉山慎, 津滝俊
    雪氷研究大会(オンライン) 2020年11月 口頭発表(一般)
  • Shin Sugiyama
    Cold Land Seminar “Japanese-Russian collaboration in the North” 2020年09月 口頭発表(招待・特別)
  • Hot-water drilling for exploring subglacial environment of the Antarctic ice sheet  [招待講演]
    Shin Sugiyama, Masahiro Minowa
    JpGU-AGU Joint Meeting 2020 2020年07月 口頭発表(招待・特別)
  • Short-term ice speed variations near the calving front of Bowdoin Glacier, northwestern Greenland  [通常講演]
    Shin Sugiyama, Shun Tsutaki, Daiki Sakakibara, Izumi Asaji
    Workshop on the Dynamics and Mass Budget of Arctic Glaciers & the IASC Network on Arctic Glaciology Annual Meeting 2020年01月 口頭発表(一般)
  • Changing natural environment and its impact on human society in Qaanaaq, northwestern Greenland  [通常講演]
    Shin Sugiyama, ArCS Greenland Project member
    Greenland Science Week 2019 2019年12月 口頭発表(一般)
  • Seasonal variations in temperature, salinity and current under the floating tongue of Langhovde Glacier in East Antarctica  [通常講演]
    Sugiyama, S, M. Minowa, S. Aoki
    Forum for Research into Ice Shelf Processes (FRISP) 2019年09月 口頭発表(一般)
  • 南極ラングホブデ氷河の棚氷下における通年海洋観測  [通常講演]
    杉山慎, 箕輪昌紘
    雪氷研究大会 2019年09月 口頭発表(一般)
  • Mass loss of the Antarctic ice sheet under the influence of ice-ocean interaction  [招待講演]
    杉山 慎
    日本地球惑星科学連合2019年大会 2019年05月 口頭発表(招待・特別)
  • Glacier change, ice-ocean interaction, and their impacts on human society in Qaanaaq, northwestern Greenland  [通常講演]
    Shin Sugiyama
    IASC Workshop on the dynamicsand mass budget of Arctic glaciersand mass budget of Arctic glaciers& proglacial marine ecosystems& proglacial marine e 2019年01月 口頭発表(一般)
  • Changing Natural Environment and its Impact on Human Society in Greenland  [招待講演]
    SUGIYAMA Shin
    International Law for Sustainability in Arctic Resource Development:Integrating economic, social, environmental and scientific dimensions 2018年12月 口頭発表(招待・特別)
  • Hot water drilling at Langhovde Glacier, East Antarctica  [通常講演]
    Sugiyama S, Minowa, M, Masato, I, Yamane, S, Aoki, S, Tamura, T
    GRAntarctic-NIPR Joint International Symposium on Ice-Ocean Interaction 2018年12月 口頭発表(一般)
  • Hot water drilling and subshelf measurements at Langhovde Glacier, East Antarctica  [通常講演]
    Shin Sugiyama, Masahiro Minowa, Masato Ito, Shiori Yamane, Shigeru Aoki, Takeshi Tamura
    日本地球惑星科学連合2018年大会 2018年05月 口頭発表(一般)
  • 南極ラングホブデ氷河における熱水掘削  [通常講演]
    杉山慎, 箕輪昌紘, 伊藤優人, 山根志織
    雪氷学会北海道支部研究発表会 2018年05月 口頭発表(一般)
  • Coastal environment change and its impact on human society in northwestern Greenland  [招待講演]
    Shin Sugiyama
    JSPS Japan-Norway Symposium 2017年06月 口頭発表(一般)
  • Cryosphere - Greenland Ice Cap and Baffin Bay  [招待講演]
    杉山 慎
    IMBeR, Arctic Continental Margins Workshop 2017年03月 口頭発表(招待・特別)
  • Calving front of Grey Glacier in Patagonia is protruding into water under the lake surface  [通常講演]
    Shin Sugiyama, Masahiro Minowa, Marius Schaefer
    International Symposium on the Cryosphere in a Changing Climate 2017年02月 ポスター発表
  • Mass loss of outlet glaciers and ice caps in the Qaanaaq region, northwestern Greenland  [通常講演]
    Shin Sugiyama, Shun Tsutaki, Daiki Sakakibara, Evgeny Podolskiy, Masahiro Minowa, Yoshihiko Ohashi, Martin Funk, Guillaume Jouvet, Julien Seguinot, Yvo Weidmann, Riccardo Genco
    Workshop on the Dynamics and Mass Budget of Arctic Glaciers & the IASC Network on Arctic Glaciology Annual Meeting 2017年01月 口頭発表(一般)
  • Recent ice mass loss of outlet glaciers and ice caps in the Qaanaaq region, northwestern Greenland  [通常講演]
    Sugiyama, S. S. Tsutaki, D. Sakakibara, J. Saito, Y. Ohashi, M. Maruyama, N. Katayama, E.Podolskiy, M. Minowa, S. Matsuno, T. Sawagaki, S. Matoba, M. Funk, R. Genco, H. Enomoto
    AGU fall meeting 2016年12月 ポスター発表
  • The ice sheet/glacier-ocean interaction in Greenland  [招待講演]
    Shin Sugiyama
    Arctic Circle Assembly 2016 2016年10月 口頭発表(招待・特別)
  • Ice mass loss in northwestern Greenland  [招待講演]
    Shin Sugiyama
    Japan-Norway Arctic Science & Innovation Week 2016 2016年06月 口頭発表(一般)
  • Glacier dynamics near the calving front of Bowdoin Glacier, northwestern Greenland  [通常講演]
    S. Sugiyama, S. Tsutaki, D. Sakakibara, J. Saito, M. Maruyama, N. Katayama, T. Sawagaki, M. Funk, A. Bauder
    IGS International Symposium on Contemporary Ice-Sheet Dynamics 2015年08月 口頭発表(一般)
  • Glacier dynamics near the calving front of Bowdoin Glacier, northwestern Greenland  [通常講演]
    S. Sugiyama, S. Tsutaki, D. Sakakibara, J. Saito, M. Maruyama, N. Katayama, T. Sawagaki, M. Funk, A. Bauder
    The Arctic Science Summit Week 2015 (ISAR-4/ICARP-III) 2015年04月 口頭発表(一般)
  • 片山 直紀, 津滝 俊, 榊原 大貴, 杉山 慎, 澤柿 教伸
    雪氷研究大会講演要旨集 2015年 公益社団法人 日本雪氷学会/日本雪工学会
  • 杉山 慎, ナヴァロ フランシスコ, 澤柿 教伸, 瀬川 高弘, 大沼 友貴彦, ヴァシレンコ エヴゲニ
    雪氷研究大会講演要旨集 2015年 公益社団法人 日本雪氷学会/日本雪工学会
  • Thermal structures of proglacial lakes in the Southern Patagonia Icefield  [通常講演]
    Sugiyama, S, M. Minowa, D. Sakakibara, Y. Ohashi, P. Skvarca, T. Sawagaki, N. Naito
    International Symposium on Contribution of Glaciers and Ice Sheets to Sea Level Change 2014年05月 口頭発表(一般)
  • Exploring Antarctic subglacial environment using hot water drilling  [通常講演]
    Sugiyama, S, T. Sawagaki, T. Fukuda, S. Aoki, S. Imura
    The 4th Symposium on Polar Science 2013年11月 口頭発表(一般)
  • Mass loss of glaciers and ice caps in northwestern Greenland  [通常講演]
    Sugiyama, S, S. Tsutaki, D. Sakakibara, T. Sawagaki, S. Matsuno, M. Minowa, M. Maruyama, J. Saito, S. Matoba, S. Yamaguchi
    The 4th Symposium on Polar Science 2013年11月 口頭発表(一般)
  • Warm water and life beneath the grounding zone of an Antarctic outlet glacier  [通常講演]
    Sugiyama, S, T. Sawagaki, T. Fukuda, S. Aoki
    European Geosciences Union 2013年04月 口頭発表(一般)
  • Ice mass loss in northwestern Greenland  [通常講演]
    Sugiyama, S. Matoba, S. Yamaguchi, D. Sakakibara, S. Matsuno
    3rd International Symposium on Arctic Research 2013年01月 口頭発表(一般)
  • Hot water drilling and measurements beneath the grounding zone of Langhovde Glacier, East Antarctica  [通常講演]
    Sugiyama, S, T. Sawagaki, T. Fukuda
    3rd Symposium on Polar Science 2012年11月 口頭発表(一般)
  • Hot water drilling and subglacial observations at the floating tongue of Langhovde Glacier, East Antarctica  [通常講演]
    Sugiyama, S, T. Sawagaki, T. Fukuda
    International Symposium on Glaciers and Ice 2012年06月 口頭発表(一般)
  • Hot water drilling and subglacial measurements at the floating tongue of Langhovde Glacier, East Antarctica  [通常講演]
    Sugiyama, S, T. Sawagaki, T. Fukuda
    26th International Forum for Research into Ice Shelf Processes 2012年06月 口頭発表(一般)
  • Calving glacier dynamics controlled by subglacial water pressure close to ice overburden pressure in Glaciar Perito Moreno, Patagoniaa  [通常講演]
    Sugiyama, S. P. Skvarca, N. Naito, H. Enomoto, K. Tone, S. Tsutaki, S. Marinsek, M. Aniya
    European Geosciences Union General Assembly 2011年04月 口頭発表(一般)
  • Daisuke Nishimura, Shun Tsutaki, Shin Sugiyama, Daisuke Nishimura, Shun Tsutaki
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2011年
  • Calving Glacier Dynamics Controlled by Small Fluctuations in Subglacial Water Pressure Revealed by Hot Water Drilling in Glaciar Perito Moreno, Patagonia  [通常講演]
    Sugiyama, S. P. Skvarca, N. Naito, H. Enomoto, K. Tone, S. Tsutaki, M. Aniya
    American Geophysical Union Annual Fall Meeting 2010年12月 口頭発表(一般)
  • Hiroaki Ota, Takeshi Hashimoto, Yohei Nagakura, Shuhei Takamura, Akira Fukuda, Masamu Aniya, Nozomu Naito, Hiroyuki Enomoto, Shin Sugiyama, Pedro Skvarca
    International Conference on Humans and Computers, HC '10, Aizu-Wakamatsu, Fukushima-ken, Japan, December 6-10, 2010 2010年 University of Aizu Press / ACM
  • Shin Sugiyama, Nozomu Naito, Kenta Tone, Hiroyuki Enomoto, Pedro Skvarca, Masamu Aniya
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2010年
  • Shun Tsutaki, Daisuke Nishimura, Takeshi Yoshizawa, Shin Sugiyama
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2010年
  • Takehiro Fukuda, Shin Sugiyama
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2010年
  • Akane Tsushima, Hirotaka Sasaki, Takehiro Fukuda, Sumito Matoba, Sachiko Okamoto, Shin Sugiyama, Takayuki Shiraiwa, Daniel Solie, Kenji Yoshikawa
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2010年
  • Snow density and dielectric constant measurements along the traverse route of the Japanese-Swedish Antarctic Expedition 2007-2008  [通常講演]
    Sugiyama, S, H. Enomoto, S. Fujita
    International Symposium on Glaciology in the International Polar Year 2009年07月 口頭発表(一般)
  • Takeshi Yoshizawa, Shin Sugiyama, Matthias Huss
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2009年
  • Daisuke Nishimura, Shun Tsutaki, Shin Sugiyama
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2009年
  • Shin Sugiyama, Shun Tsutaki, Nozomu Naito, Hiroyuki Enomoto, Pedro Skvarca
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2009年
  • Hiroyuki Enomoto, Nozomu Naito, Shin Sugiyama, Shun Tsutaki, Akira Fukuda, Masamu Aniya, Shinji Isono, Pedro Skvarca
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2009年
  • Shun Tsutaki, Shin Sugiyama
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2009年
  • Katsumi Yamanoi, Shin Sugiyama, Hitoshi Onishi, Manami Takahashi, Kazuki Nakamura
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2009年
  • Takehiro Fukuda, Shin Sugiyama, Sumito Matoba, Takayuki Shiraiwa
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2009年
  • Modelling the flow regime of the Antarctic drainage system from Dome F to Shirase Glacier  [通常講演]
    Sugiyama, S, R. Greve, T. Zwinger, H. Seddik
    American Geophysical Union Annual Fall Meeting 2008年12月 ポスター発表
  • Sideways ice motion during speed-up events in Gornergletscher, Switzerland  [通常講演]
    Sugiyama, S, A. Bauder, M. Funk
    International Symposium on Dynamics in Glaciology 2008年08月 口頭発表(一般)
  • Shin Sugiyama, Hiroyuki Enomoto, Shuji Fujita
    Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2008年
  • Evolution of Rhonegletscher in Switzerland over the past 125 years and in the future  [通常講演]
    Sugiyama, S, C. Zahno, A. Bauder, M. Funk
    International Symposium on Cryospheric Indicators of Global Climate Change 2006年08月 口頭発表(一般)
  • Evolution of Rhonegletscher in Switzerland over the past 125 years and in the future: application of an improved flowline model  [通常講演]
    Sugiyama, S, C. Zahno, A. Bauder, M. Funk
    1st Asia CliC Symposium 2006年04月 口頭発表(一般)
  • Glacier dynamics during the outburst flood of a glacier dammed lake on Gornergletscher, Switzerland  [通常講演]
    Sugiyama, S, M. Funk, B. Mueller, A. Bauder, U. H. Fischer, P. Weiss, M. Huss, N. Deichmann, H. Blatter
    European Geosciences Union General Assembly 2005年04月 口頭発表(一般)
  • Laboratory experiment of basal siding  [通常講演]
    Sugiyama, S, R. Naruse
    European Geosciences Union General Assembly 2004年04月 口頭発表(一般)

作品等

その他活動・業績

受賞

  • 2022年09月 講談社 第38回講談社科学出版賞
     南極の氷に何が起きているか ー気候変動と氷床の科学 
    受賞者: 杉山慎
  • 2019年05月 日本雪氷学会 北海道支部 北海道雪氷賞(北の六華賞)
     南極ラングホブデ氷河における熱水掘削 
    受賞者: 杉山 慎
  • 2015年03月 北海道大学 教育総長奨励賞
     
    受賞者: 杉山 慎
  • 2013年09月 社団法人日本雪氷学会 学術賞
     氷河・氷床の底面動力学プロセスの研究 
    受賞者: 杉山 慎
  • 2011年 社団法人日本雪氷学会 2011年度 論文賞

共同研究・競争的資金等の研究課題

  • 国立極地研究所:第Ⅹ期南極地域観測事業観測課題
    研究期間 : 2022年04月 -2028年03月 
    代表者 : 奈良間千之, 箕輪昌紘, 澤柿教伸, 庭野匡思, 山之口勤, 中村和樹, 青山雄一
  • 多様なスケールと手法で明らかにする急激な北極域氷河氷床変動
    文部科学省:北極域研究加速プロジェクト(ArCS Ⅱ) 海外研究力強化プログラム
    研究期間 : 2021年04月 -2025年03月 
    代表者 : Thomas Schuler、Ralf Greve、古屋正人、Evgeny Podolskiy
  • 文部科学省:ArCS II(環境技術等研究開発推進事業費補助金)
    研究期間 : 2020年06月 -2025年03月
  • 日本学術振興会:科学研究費助成事業 基盤研究(A)
    研究期間 : 2020年04月 -2025年03月 
    代表者 : 杉山 慎
  • 日本学術振興会:科学研究費助成事業 新学術領域研究(研究領域提案型)
    研究期間 : 2017年06月 -2022年03月 
    代表者 : 川村 賢二, 植村 立, 本山 秀明, 杉山 慎, 澤柿 教伸
     
    <氷床コア関連>ドームふじ氷床コアの各分析やデータ解析により環境復元や変動メカニズム解析を進めるとともに、同コアと他のアイスコアや海底コアとの年代統合や環境復元に関するデータをさらに蓄積した。特に、約12万年前や約40万年前の間氷期について、ドームふじコアの気体分析や取得済みデータの解析を進め、精密年代統合に寄与するデータを得た。最終間氷期前の氷期最寒期を対象に、ドームふじコアのメタン濃度及びO2同位体比の詳細データから、間氷期に至る退氷の始まりを示す可能性のある変化を見出した。ダストやエアロゾルに関する各種分析・解析の結果は複数の論文として出版した。CO2濃度復元を目的とした切削法抽出装置を組み上げ、テスト分析が可能になった。ドームふじコアの年代軸の刷新に向けた年代モデルにかかる共同研究も進めた。フィルン空気や積雪の分析なども引き続き進め、氷床コアへの環境情報記録プロセスの研究も進めた。 <広域雪氷観測>東南極ドロンニングモードランド(DML)地域の表面質量収支の時空間変動を明らかにするため、1990年代から取得されてきた雪尺等の観測データの解析(データの代表性や不確実性検討、モデル班や公募班との連携)を進めた。昨シーズンの国際共同観測(日本、米国、ノルウェー)を含む内陸の雪氷観測データについて、基盤地形の精緻化や氷床流動、表面質量収支に着目して解析を進めた。 <氷河・海洋観測>ラングホブデ氷河に初年度に観測した棚氷下の海洋データと、棚氷下に設置した係留系から通年で得られたデータを解析し、季節・経年変化を含めた底面融解の理解を進めた。人工衛星データや気象データの解析、他班との意見交換を通じ、海洋変化と氷床変動の関係や、氷床融解が海洋環境にもたらす影響の検討を進めた。棚氷下で採取した海水や海底堆積物の分析を実施した。
  • 文部科学省・国立極地研究所:南極地域観測第9期重点研究観測
    研究期間 : 2017年04月 -2022年03月
  • 日本学術振興会:科学研究費助成事業 基盤研究(A)
    研究期間 : 2017年04月 -2020年03月 
    代表者 : 三寺 史夫, 白岩 孝行, 立花 義裕, 的場 澄人, 杉山 慎, 美山 透, 中村 知裕, 西岡 純
     
    親潮域は、世界でも稀な豊かな海である。その要因は「アムール川流域の湿原から流出し、オホーツク海大陸棚から海洋中層循環を通して供給される鉄分」を介した「陸海結合システム」にある。本課題では、大気変動を海洋に伝えるカムチャツカ半島の降水・雪氷・河川に着目し、海洋子午面循環を駆動する塩分変動の要因、またそれに基づく「陸海結合システム」に対する制御メカニズムの解明を目指した。その結果、(1)カムチャツカ半島からの河川流出量は、アムール川の約80%という大きなものであること、(2)中層循環を駆動する塩分に対して、アムール川よりはむしろカムチャツカ河川流出水からの影響が大きいこと、が明らかとなった。
  • 日本学術振興会:科学研究費補助金(基盤B・海外学術)
    研究期間 : 2016年04月 -2020年03月 
    代表者 : 杉山 慎
  • 文部科学省:ArCS北極域研究推進プロジェクト
    研究期間 : 2015年10月 -2020年03月
  • 日本学術振興会:科学研究費補助金(挑戦的萌芽研究)
    研究期間 : 2014年04月 -2017年03月 
    代表者 : 杉山 慎
  • カービング氷河の急激な後退に氷河流動が果たす役割
    日本学術振興会:科学研究費補助金(基盤研究B)
    研究期間 : 2011年 -2015年 
    代表者 : 杉山 慎
  • Role of ice dynamics in rapid retreat of calving glaciers
    Grant-in-Aid for Scientific Research
    研究期間 : 2011年 -2015年
  • 南極沿岸における溢流氷河の短期流動変化
    日本学術振興会:科学研究費補助金(挑戦的萌芽研究)
    研究期間 : 2011年 -2014年 
    代表者 : 杉山 慎
  • Short term flow speed variations in an Antarctic outlet glacier
    Grant-in-Aid for Scientific Research
    研究期間 : 2011年 -2013年
  • 国立極地研究所:南極地域観測第8期一般研究観測
    研究期間 : 2010年 -2012年 
    代表者 : 杉山 慎
  • Hot water drilling at Langhovde Glacier, East Antarctica
    0100 (Japanese Only)
    研究期間 : 2010年 -2012年
  • 氷河湖の形成に起因した氷河後退メカニズムの解明
    日本学術振興会:科学研究費補助金(基盤研究C)
    研究期間 : 2008年 -2011年 
    代表者 : 杉山 慎
  • 高精度氷河変動モデルの構築
    日本学術振興会:科学研究費補助金(若手研究)
    研究期間 : 2006年 -2008年 
    代表者 : 杉山 慎

教育活動情報

主要な担当授業

  • 大学院共通授業科目(教育プログラム):南極学
    開講年度 : 2021年
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
    キーワード : Polar regions, the Antarctic, the Arctic, sea ice, ice sheet, atmosphere, ocean, climate system, ecosystem, Antarctic expeditions, Antarctic treaty
  • 大学院共通授業科目(教育プログラム):南極学
    開講年度 : 2021年
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
    キーワード : 野外調査、氷、雪、気象、山岳、ロープ、高山病、低体温症、救命法
  • 大学院共通授業科目(教育プログラム):南極学
    開講年度 : 2021年
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
    キーワード : 氷河、雪、氷、凍土、気象、アルプス、山岳、環境科学
  • 氷河・氷床学特論
    開講年度 : 2021年
    課程区分 : 修士課程
    開講学部 : 環境科学院
    キーワード : 氷河、氷床、地球環境、雪、氷、永久凍土、古環境 glacier, ice sheet, earth environment, snow, ice, permafrost, paleoenvironment
  • 大学院共通授業科目(教育プログラム):南極学
    開講年度 : 2021年
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
    キーワード : snow, ice, glacier, sea ice, climate, Antarctica, Arctic, ocean, biology, Plankton, Euphausia
  • 大学院共通授業科目(教育プログラム):南極学
    開講年度 : 2021年
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
    キーワード : 野外観測、降雪、積雪、気象、水文
  • 地球雪氷学基礎論
    開講年度 : 2021年
    課程区分 : 修士課程
    開講学部 : 環境科学院
    キーワード : 雪氷・寒冷圏、雪、氷、極地 cryosphere, snow, ice, polar regions
  • 一般教育演習(フレッシュマンセミナー)
    開講年度 : 2021年
    課程区分 : 学士課程
    開講学部 : 全学教育
    キーワード : 南極、雪氷、地球環境、氷床、アイスコア、気象、海洋、海氷

大学運営

委員歴

  • 2021年07月 - 現在   Communications Earth & Environment   Editorial Board Member
  • 2018年 - 現在   日本雪氷学会・氷河情報センター   センター長
  • 2017年 - 現在   日本雪氷学会・北海道支部   副支部長
  • 2017年 - 現在   日本雪氷学会   学術委員・学術委員長
  • 2014年 - 現在   日本学術会議   地球惑星科学委員会国際対応分科会SCAR小委員会委員
  • 2012年03月 - 現在   日本学術会議   地球惑星科学委員会IUGG分科会IACS小委員会委員
  • 2007年 - 現在   国立極地研究所   気水圏専門部会委員
  • 2021年04月 - 2023年03月   日本学術会議 環境学委員会・地球惑星科学委員会合同FE・WCRP合同分科会 CliC小委員会   委員長
  • 2015年 - 2021年   Frontiers in Earth Science   Associate Editor
  • 2017年 - 2019年   日本雪氷学会・井上基金運営委員会   委員長
  • 2013年12月 - 2019年   International Arctic Science Committee   Cryosphere WG member
  • 2015年 - 2017年   International Glaciological Society   Vice President
  • 2012年 - 2017年   北極環境研究コンソーシアム   運営委員
  • 2015年 - 2016年   文部科学省   北極研究戦略委員会 委員
  • 2010年 - 2014年   日本雪氷学会 極地雪氷分科会   幹事長
  • 2008年 - 2014年   日本雪氷学会   事業委員   日本雪氷学会
  • 2009年 - 2013年   Bulletin of Glaciological Research   編集委員
  • 2008年 - 2012年   日本雪氷学会   学術委員   日本雪氷学会
  • 2009年 - 2011年   日本雪氷学会 北海道支部   庶務担当理事
  • 2006年 - 2010年   日本雪氷学会 氷河情報センター   財務幹事

社会貢献活動

  • 南極氷床 ー地球最大の氷のかたまりー
    期間 : 2021年11月06日
    役割 : 講師
    主催者・発行元 : 北海道大学大学祭全学実行委員会
    イベント・番組・新聞雑誌名 : 北大祭公開講座
  • 期間 : 2021年11月03日
    役割 : 講師
    主催者・発行元 : 中央大学,環境社会・国際環境保全ゼミ
  • 雪について調べてみよう
    期間 : 2021年02月12日
    役割 : 講師
    主催者・発行元 : 札幌市立大倉山小学校
  • 南極氷床 -地球でいちばん大きな氷のかたまり-
    期間 : 2020年12月12日
    役割 : 講師
    主催者・発行元 : 愛知淑徳大学創造表現学会
    イベント・番組・新聞雑誌名 : SNS講演会
  • 氷河・氷床
    期間 : 2020年11月25日
    役割 : 講師
    主催者・発行元 : 北極域研究共同推進拠点
    イベント・番組・新聞雑誌名 : 北極域課題解決人材育成講座
  • 期間 : 2020年02月14日
    役割 : 講師
    主催者・発行元 : 札幌市立大倉山小学校
    小学生
  • 雪氷圏の科学
    期間 : 2020年01月17日
    役割 : 講師
    主催者・発行元 : 立命館慶祥高校
    イベント・番組・新聞雑誌名 : 立命館慶祥高校 SSH国際交流研究室訪問
  • 氷河と氷床
    期間 : 2019年10月11日
    役割 : 講師
    主催者・発行元 : 立命館慶祥高等学校
    イベント・番組・新聞雑誌名 : SSH事業 北海道大学訪問
  • 氷河・氷床 -北極を彩る氷のかたまり-
    期間 : 2019年10月09日
    役割 : 講師
    主催者・発行元 : 北極域研究共同推進拠点(J-ARC Net)
    イベント・番組・新聞雑誌名 : 北極基礎市民講座
  • 南極氷床 -地球最大の氷のかたまり-
    期間 : 2019年10月01日
    役割 : 講師
    主催者・発行元 : (公財)北海道女性協会
    イベント・番組・新聞雑誌名 : 2019年度第2期えるのす連続講座~女性大学~
  • 札幌藻岩高等学校「環境教育講座」
    期間 : 2019年09月13日
    役割 : 講師
    主催者・発行元 : 札幌藻岩高等学校
    イベント・番組・新聞雑誌名 : 環境教育講座
  • 南極氷床 ―地球最大の氷のかたまり-
    期間 : 2019年05月27日
    役割 : 講師
    主催者・発行元 : 日本地球惑星科学連合
    イベント・番組・新聞雑誌名 : JPGU2019ショートセミナー
  • ARCTIC LIFE 〜極北の狩⼈と雪氷学者を囲んで
    期間 : 2019年02月23日
    役割 : 講師
    主催者・発行元 : ⽇本科学未来館、北海道⼤学低温科学研究所、北極域研究推進プロジェクト(ArCS)
    イベント・番組・新聞雑誌名 : 日本科学未来館トークセッション
  • グリーンランドの自然環境と狩猟文化
    期間 : 2019年02月17日
    役割 : 講師
    主催者・発行元 : 紋別市
    イベント・番組・新聞雑誌名 : 第34回北方圏国際シンポジウム
  • グリーンランドの自然環境
    期間 : 2019年02月15日
    役割 : 講師
    主催者・発行元 : 北海道大学・低温科学研究所、アイヌ・先住民研究センター、北極域研究センター ・ArCSプロジェクト
    イベント・番組・新聞雑誌名 : グリーンランドとアイヌの狩猟文化:環境保全と文化継承の取り組みから
  • 雪について調べてみよう
    期間 : 2019年02月12日
    役割 : 講師
    主催者・発行元 : 札幌市立大倉山小学校
  • 立命館慶祥SSH 国際交流研究室訪問
    期間 : 2019年02月05日
    役割 : 講師
    主催者・発行元 : 立命館慶祥高等学校
  • グリーンランド ―自然環境の変化とその人間生活への影響―
    期間 : 2018年12月15日
    役割 : 講師
    主催者・発行元 : 日本科学未来館、北極域研究推進プロジェクト(ArCS)
    イベント・番組・新聞雑誌名 : トークセッション「どうなる? 北極 ~人と自然が織りなす北の叙事詩」
  • サイエンススクール ~五感で感じる南極体験~
    期間 : 2018年08月17日
    役割 : 講師
    主催者・発行元 : KDDI、北海道大学
  • 氷河 ─地球を彩る氷─
    期間 : 2017年10月31日
    役割 : 講師
    主催者・発行元 : 北海道立女性プラザ
    イベント・番組・新聞雑誌名 : 平成29年度第2期女性大学
  • 圧巻!極北の大瀑布 ノルウェースバールバル諸島
    期間 : 2017年10月21日
    役割 : 助言・指導
    主催者・発行元 : NHK
    イベント・番組・新聞雑誌名 : グレートネイチャー
  • ののちゃんdo科学「氷山と流氷」
    期間 : 2017年10月14日
    役割 : 情報提供
    イベント・番組・新聞雑誌名 : 朝日新聞
  • 南極氷床 -地球最大の氷のかたまり―
    期間 : 2017年05月22日 - 2017年05月22日
    役割 : 講師
    主催者・発行元 : 立命館慶祥高等学校
    イベント・番組・新聞雑誌名 : SSH特別授業「サイエンスチャージ」
  • 科学の扉「極地の氷消える時」
    期間 : 2017年05月07日
    役割 : 情報提供
    イベント・番組・新聞雑誌名 : 朝日新聞
  • 「雪について調べよう」
    期間 : 2017年02月01日
    役割 : 講師
    主催者・発行元 : 札幌市立大倉山小学校
  • グリーンランドをめぐる「音楽」・「冒険」・「サイエンス」
    期間 : 2016年11月07日
    役割 : 司会
    主催者・発行元 : 低温科学研究所、北極域研究センター、MUSIC PLANT
    イベント・番組・新聞雑誌名 : 北海道大学サステナビリティウィーク
  • グリーンランド氷床 北極最大の氷のかたまりに何が起きているか
    期間 : 2016年10月02日
    役割 : パネリスト
    イベント・番組・新聞雑誌名 : 雪氷研究大会公開講演会「極地からの緊急報告! 温暖化がすすむ南極とグリーンランドに迫る」
  • 氷河氷床 地球の氷に何が起きているのか?
    期間 : 2016年09月26日
    役割 : 講師
    イベント・番組・新聞雑誌名 : 低温科学研究所公開講座「広がる低温の魅力 低温科学の最前線」
  • GRENEプロジェクト 公開講演会
    期間 : 2016年03月05日
    役割 : パネリスト
    主催者・発行元 : 国立極地研究所・JAMSTEC・北海道大学
    イベント・番組・新聞雑誌名 : 北極温暖化の実態と影響~何がわかったか、これから何をするのか~
  • ポプラ広場「地球温暖化最前線 スイスアルプスの氷河と地球の未来」
    期間 : 2016年02月18日
    役割 : 講師
    主催者・発行元 : 朝日新聞北海道支社、北海道テレビ放送
  • 「雪について調べよう」
    期間 : 2016年01月15日
    役割 : 講師
    主催者・発行元 : 大倉山小学校
  • 札幌立命館慶祥高校SSH大学研修
    期間 : 2015年06月13日 - 2015年06月13日
    役割 : 講師
    主催者・発行元 : 低温科学研究所・立命館慶祥高校
  • 北海道大学インフォメーションセンター公開展示
    期間 : 2015年03月 - 2015年05月
    役割 : 情報提供
    主催者・発行元 : 低温科学研究所・北海道テレビ(HTB)
  • 公開講演会 富山に北極がやって来た!
    期間 : 2015年04月26日
    役割 : パネリスト
    主催者・発行元 : 国立極地研究所ほか
    イベント・番組・新聞雑誌名 : 北極科学サミット週間(Arctic Science Summit Week)
  • ポプラ広場「地球温暖化最前線 南米パタゴニアの氷河と地球の未来」
    期間 : 2015年03月19日
    役割 : 講師
    主催者・発行元 : 朝日新聞北海道支社、北海道テレビ放送
  • 「雪について調べよう」
    期間 : 2015年03月09日
    役割 : 講師
    主催者・発行元 : 大倉山小学校
  • 期間 : 2014年09月25日
    役割 : 講師
    主催者・発行元 : 北海道大学
    イベント・番組・新聞雑誌名 : 札幌国際芸術祭「北大アーティストカフェ」
  • 旭川西高等学校SSH大学研修
    期間 : 2014年04月24日
    役割 : 講師
    主催者・発行元 : 低温科学研究所
  • 期間 : 2014年03月15日 - 2014年03月15日
    役割 : 講師
    主催者・発行元 : 北極環境研究コンソーシアム/国立極地研究所
    イベント・番組・新聞雑誌名 : 公開講演会「遠くて近い北極 -ここまでわかった温暖化-」
  • 「雪について調べよう」
    期間 : 2014年02月25日
    役割 : 講師
    主催者・発行元 : 大倉山小学校
  • 「スペースシップアースの未来 」
    期間 : 2014年01月17日
    役割 : 情報提供
    主催者・発行元 : NHK
  • 「南極・北極の氷床に何が起きているか」
    期間 : 2013年11月26日
    役割 : 講師
    主催者・発行元 : 北海道大学
    イベント・番組・新聞雑誌名 : 遠友学舎夜学校
  • 「グリーンランドの氷床を探る」
    期間 : 2013年11月12日
    役割 : 報告書執筆
    主催者・発行元 : 朝日新聞
    イベント・番組・新聞雑誌名 : 北の文化
  • 「氷の大地グリーンランド -北極最大の氷のかたまりに何が起きているのか-」
    期間 : 2013年11月03日
    役割 : 講師
    主催者・発行元 : 北海道テレビ・北海道大学総合博物館・低温科学研究所
    イベント・番組・新聞雑誌名 : 白夜の北極・グリーンランド展 市民セミナー
  • 「南極氷床 ~氷の底を覗いてみたら~」
    期間 : 2013年08月11日
    役割 : 講師
    主催者・発行元 : 愛媛県総合科学博物館
    イベント・番組・新聞雑誌名 : 特別展「南極の自然」
  • 「南極氷床」
    期間 : 2013年06月08日
    役割 : 講師
    主催者・発行元 : 札幌立命館慶祥高校
    イベント・番組・新聞雑誌名 : スーパーサイエンスハイスクール
  • 「日本隊とスウェーデン隊の南極旅行術」
    期間 : 2012年09月25日
    役割 : 講師
    主催者・発行元 : 日本雪氷学会
    イベント・番組・新聞雑誌名 : 雪氷研究大会 公開シンポジウム「南極の食生活いまむかし」
  • 南極氷床 - 地球でいちばん大きな氷のかたまり」
    期間 : 2012年08月25日
    役割 : 講師
    主催者・発行元 : 北海道大学総合博物館
    イベント・番組・新聞雑誌名 : 南極フロンティア展
  • 氷河氷床と気候変動
    期間 : 2011年11月15日
    役割 : 講師
    主催者・発行元 : 札幌管区気象台
  • 宙と陸から観る 氷河・氷床の今
    期間 : 2011年10月30日
    役割 : 講師
    主催者・発行元 : 北海道大学
    イベント・番組・新聞雑誌名 : GiFT 北海道大学から世界へ未来へ
  • 南極氷床 — 雪と氷の大陸が地球環境に果たす役割 —
    期間 : 2010年10月30日
    役割 : パネリスト
    主催者・発行元 : 札幌管区気象台、稚内地方気象台
    イベント・番組・新聞雑誌名 : 地球環境シンポジウム 「どう変わる 私たちの住む宗谷 私たちの住む地球 稚内と南極から見つめる地球環境」

メディア報道

  • 流れ出す氷河に迫る 熱水掘削し過程観測、氷床融解予測に活用
    報道 : 2022年01月09日
    発行元・放送局 : 共同通信社
    番組・新聞雑誌 : 岩手日報その他
  • 「南極の氷に何が起きているか 気候変動と氷床の科学」=杉山慎・著
    報道 : 2022年01月08日
    番組・新聞雑誌 : 毎日新聞
  • グリーンランドで氷河の融解が21世紀に入って急加速したことが判明
    報道 : 2021年12月13日
    発行元・放送局 : 共同通信社
  • 報道 : 2021年11月18日
    番組・新聞雑誌 : 日刊工業新聞
  • 最北の陸地に世界が注目・グリーンランドの北に新たに発見
    報道 : 2021年10月08日
    執筆者 : 本人以外
    発行元・放送局 : 朝日新聞
    番組・新聞雑誌 : 朝日小学生新聞
     新聞・雑誌
  • 報道 : 2021年08月23日
    番組・新聞雑誌 : 日経新聞
     新聞・雑誌
  • 10YearsAfter未来への分岐点
    報道 : 2020年01月
    発行元・放送局 : NHK
    番組・新聞雑誌 : NHKスペシャル
     テレビ・ラジオ番組
  • 波乱の北極カメラ回収
    報道 : 2018年09月30日
    発行元・放送局 : 日本テレビ 所さんの目がテン!
     テレビ・ラジオ番組
  • ~グリーンランドの科学~
    報道 : 2017年07月
    発行元・放送局 : 日本テレビ
    番組・新聞雑誌 : 所さんの目がテン!
     テレビ・ラジオ番組
  • とけてゆくスイス「氷河×光×地球の未来」
    報道 : 2016年02月11日
    発行元・放送局 : 北海道テレビ放送
     テレビ・ラジオ番組
  • 報道 : 2015年02月11日
    発行元・放送局 : 北海道テレビ放送
     テレビ・ラジオ番組
  • 報道 : 2014年09月19日
    発行元・放送局 : JST科学技術振興機構
    番組・新聞雑誌 : サイエンスチャンネル
     インターネットメディア
  • 「地球変動氷点下で探る」
    報道 : 2014年02月06日
    番組・新聞雑誌 : 日経新聞
     新聞・雑誌
  • 報道 : 2013年11月04日
    発行元・放送局 : 北海道テレビ
     テレビ・ラジオ番組
  • 報道 : 2013年05月19日
    発行元・放送局 : NHK
    番組・新聞雑誌 : サイエンスゼロ
     テレビ・ラジオ番組


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