Researcher basic information

• Ph.D., The University of Tokyo

• https://researchmap.jp/tomoirino?lang=en

• https://orcid.org/0000-0001-6941-770X
• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=200901072141492364
• https://pablos.ees.hokudai.ac.jp/irino/
• https://pablos.ees.hokudai.ac.jp/irino/en/

• https://orcid.org/0000-0001-6941-770X

• D-9282-2018

• 200901072141492364

• 古気候学
• sedimentology
• stratigraphy
• inorganic geochemistry
• isotope geochemistry

• Natural Science, Solid earth sciences

• Master's degree program, Graduate School of Environmental Science
• Doctoral (PhD) degree program, Graduate School of Environmental Science

Research activity information

• Sep. 2019, 日本地質学会, The Geological Society of Japan Best Paper Award
  Depositional ages and characteristics of Middle‒Upper Jurassic and Lower Cretaceous lacustrine deposits in southeastern Mongolia. Island Arc 27-3, 2018. DOI: 10.1111/iar.12243
  Hasegawa, H;Ando, H;Hasebe, N;Ichinnorov, N;Ohta, T;Hasegawa, T;Yamamoto, M;Li, G;Erdenetsogt, B.-O;Heimhofer, U;Murata, T;Shinya, H;Enerel, G;Oyunjargal, G;Munkhtsetseg, O;Suzuki, N;Irino, T;Yamamoto, K
• Jun. 2014, Paleontological Society of Japan, 2014 Best Paper Award
  Kitamura, A., Kobayashi, K., Tamaki, C., Yamamoto, N., Irino, T., Miyairi, Y., and Yokoyama, Y., Evidence of recent warming in the Okinawa region, subtropical northwestern Pacific, from an oxygen isotope record of a cave-dwelling marine micro-bivalve, Pal
  北村晃寿;小林小夏;玉置周子;山本なぎさ;入野智久;宮入陽介;横山祐典
• Aug. 2010, 日本第四紀学会, 日本第四紀学会論文賞
  青木かおり・入野智久・大場忠道（2008）「鹿島沖海底コアMD01-2421の後期更新世テフラ層序」第四紀研究、47巻、6号、391-407.
  青木かおり;入野智久;大場忠道, Japan

• Estimation of dry bulk density of marine core sediments using an XRF core scanner
  Kaz Mitake; Arisa Seki; Ryuji Tada; Tomohisa Irino; Masafumi Murayama
  Progress in Earth and Planetary Science, 30 Mar. 2026
  Scientific journal
• Two-Layered South Pacific Carbon Reservoirs and Deep-Water Export to the Atlantic During CO₂ Drawdowns Since the Last Interglacial
  Shinya Iwasaki; Katsunori Kimoto; Lester Lembke-Jene; Igor M. Venancio; Tomohisa Irino; Hidetaka Kobayashi; Frank Lamy
  14 Mar. 2026
• Reconstructed CO2 variability over the entire Pleistocene inferred from sedimentary leaf wax carbon isotopes from the Bay of Bengal
  Masanobu Yamamoto; Tomohisa Irino; Renata Szarek; Osamu Seki; Ayako Abe-Ouchi; Masakazu Yoshimori
  13 Mar. 2026
• Changes in Sea Surface Temperatures and Primary Productivity in the Northern Japan Sea Since the Pliocene
  Chiaki Aoyagi; Satoshi Furota; Tomohisa Irino; Ken Sawada
  02 Mar. 2026
• Bølling-Allerød meltwater discharge from the Laurentide Ice Sheet: Arctic Ocean sedimentary evidence
  Kenta Suzuki; Masanobu Yamamoto; Leonid Polyak; Tomohisa Irino; Toshiro Yamanaka; Seung-Il Nam
  Global and Planetary Change, 105406, 105406, Elsevier BV, Mar. 2026
  Scientific journal
• Factors controlling the concentration of water-soluble pyrogenic carbon in aerosols in Hokkaido, Japan
  Riku Miyase; Yuzo Miyazaki; Tomohisa Irino; Youhei Yamashita
  Atmospheric Chemistry and Physics, 10 Feb. 2026
  Scientific journal
• Rapid Holocene deposition in the Mackenzie Trough and Barrow Canyon areas in the western Arctic Ocean
  Masanobu Yamamoto; Kenta Suzuki; Masafumi Murayama; Laura Gemery; Koji Seike; Leonid Polyak; Young Jin Joe; Shoma Uchida; Minoru Kobayashi; Jonaotaro Onodera; Keiji Horikawa; Yuhji Yamamoto; Takayuki Omori; Michinobu Kuwae; Tomohisa Irino; Yutaka Y. Watanabe; Motoyo Itoh; Eiji Watanabe
  Progress in Earth and Planetary Science, 12, 1, Springer Science and Business Media LLC, 28 Jul. 2025
  Scientific journal, Abstract
  
  The Arctic Ocean and terrestrial environment have recently been reported to be changing drastically, but it is unclear whether these changes are similar to natural variations in the past or how sudden and large the changes are compared to natural variations. This premise served as motivation to collect sediment cores during the summer of 2022 at four sites on the Canadian continental shelf and Alaskan upper continental slope to reconstruct changes in the marine and terrestrial environments to provide a comprehensive picture of the ocean environment during the preindustrial period before anthropogenic influences. We dated the sediments based on the ¹³⁷Cs radioactivity of bulk sediments and the ¹⁴C concentrations of mollusk shells. The ¹³⁷Cs radioactivity shows a distinct onset corresponding to 1950 Common Era (CE) and the most prominent peak corresponding to 1963 CE. Multiple peaks appeared above the most prominent one, coinciding with nuclear power plant accidents in 1986 and 2011. Inventories of excess ²¹⁰Pb in all cores exceed the estimated supply of excess ²¹⁰Pb from atmospheric deposition, likely due to the scavenging supply of excess ²¹⁰Pb. By comparing ¹³⁷Cs and radiocarbon conventional ages, we estimated the local radiocarbon reservoir age value of each site. Using these local radiocarbon reservoir age and the conventional ages of mollusk shell samples, we established the age-depth models by the Bayesian method. The optimal ΔR values were 598, 511, 65, and –60 years at the MT1, MT2, BC2, and BC2-2 sites, respectively. The cores consist of clayey silts continuously deposited with uniquely high sedimentation rates of 0.17 to 0.74 cm y⁻¹. Variation in the Ca/Ti ratio indicates ~ 20, ~ 30, 50–60, 100–125, and 300-year cycles, likely attributed to the variation in the Aleutian Low that controls the Bering Strait inflow of Pacific waters influencing our core sites. These sediments will be used for further high-resolution, multi-proxy studies with forthcoming results.
• Supplementary material to "Factors controlling the concentration of water-soluble pyrogenic carbon in aerosols in Hokkaido, Japan"
  Riku Miyase; Yuzo Miyazaki; Tomohisa Irino; Youhei Yamashita
  02 Jul. 2025
• Orbital-scale competition of biogenic carbonate and opal production at the Del Caño Rise in the Indian sector of the Southern Ocean during the late Pleistocene 
  Hyuk Choi; Matthieu Civel-Mazens; Xavier Crosta; Isabelle Billy; Tomohisa Irino; Hiroyuki Takata; Sangbeom Ha; Boo-keun Khim
  20 Jan. 2025
• Atmospheric particulates over the northwestern Pacific during the late Holocene: Volcanism, dust, and human perturbation
  Samuel K. Marx; James Hooper; Tomohisa Irino; Nicola Stromsoe; Krystyna M. Saunders; Osamu Seki; Anthony Dosseto; Andrea Johansen; Quan Hua; Florian Dux; Geraldine Jacobsen; Atun Zawadzki
  Science Advances, 25 Oct. 2024
  Scientific journal
• Multiple episodes of ice loss from the Wilkes Subglacial Basin during the Last Interglacial
  Mutsumi Iizuka; Osamu Seki; David J. Wilson; Yusuke Suganuma; Keiji Horikawa; Tina van de Flierdt; Minoru Ikehara; Takuya Itaki; Tomohisa Irino; Masanobu Yamamoto; Motohiro Hirabayashi; Hiroyuki Matsuzaki; Saiko Sugisaki
  Nature Communications, 14, 1, Springer Science and Business Media LLC, 18 Apr. 2023
  Scientific journal, Abstract
  
  The Last Interglacial (LIG: 130,000–115,000 years ago) was a period of warmer global mean temperatures and higher and more variable sea levels than the Holocene (11,700–0 years ago). Therefore, a better understanding of Antarctic ice-sheet dynamics during this interval would provide valuable insights for projecting sea-level change in future warming scenarios. Here we present a high-resolution record constraining ice-sheet changes in the Wilkes Subglacial Basin (WSB) of East Antarctica during the LIG, based on analysis of sediment provenance and an ice melt proxy in a marine sediment core retrieved from the Wilkes Land margin. Our sedimentary records, together with existing ice-core records, reveal dynamic fluctuations of the ice sheet in the WSB, with thinning, melting, and potentially retreat leading to ice loss during both early and late stages of the LIG. We suggest that such changes along the East Antarctic Ice Sheet margin may have contributed to fluctuating global sea levels during the LIG.
• Beppu Bay, Japan, as a candidate Global Boundaries Stratotype Section and Point for an Anthropocene series
  Michinobu Kuwae; Bruce P Finney; Zhiyuan Shi; Aya Sakaguchi; Narumi Tsugeki; Takayuki Omori; Tetsuro Agusa; Yoshiaki Suzuki; Yusuke Yokoyama; Hirofumi Hinata; Yoshio Hatada; Jun Inoue; Kazumi Matsuoka; Misaki Shimada; Hikaru Takahara; Shin Takahashi; Daisuke Ueno; Atsuko Amano; Jun Tsutsumi; Masanobu Yamamoto; Keiji Takemura; Keitaro Yamada; Ken Ikehara; Tsuyoshi Haraguchi; Stephen Tims; Michaela Froehlich; Leslie Keith Fifield; Takahiro Aze; Kimikazu Sasa; Tsutomu Takahashi; Masumi Matsumura; Yukinori Tani; Peter R Leavitt; Hideyuki Doi; Tomohisa Irino; Kazuyoshi Moriya; Akira Hayashida; Kotaro Hirose; Hidekazu Suzuki; Yoshiki Saito
  The Anthropocene Review, 205301962211350, 205301962211350, SAGE Publications, 19 Dec. 2022, [Peer-reviewed]
  Scientific journal, For assessment of the potential of the Beppu Bay sediments as a Global Boundaries Stratotype Section and Point (GSSP) candidate for the Anthropocene, we have integrated datasets of 99 proxies. The datasets for the sequences date back 100 years for most proxy records and 1300 years for several records. The cumulative number of occurrences of the anthropogenic fingerprint reveal unprecedented increases above the base of the 1953 flood layer at 64.6 cm (1953 CE), which coincides with an initial increase in global fallout of ²³⁹Pu+²⁴⁰Pu. The onset of the proliferation of anthropogenic fingerprints was followed by diverse human-associated events, including a rapid increase in percent modern ¹⁴C in anchovy scales, changes in nitrogen and carbon cycling as recorded by anchovy δ¹⁵N and δ¹³C, elevated pollution of heavy metals, increased depositions of novel materials (spheroidal carbonaceous particles, microplastics, polychlorinated biphenyls), the occurrence of hypoxia (Re/Mo ratio) and eutrophication (biogenic opal, TOC, TN, diatoms, chlorophyll a), unprecedented microplankton community changes (compositions of carotenoids, diatoms, dinoflagellates), abnormally high spring air temperatures as inferred from diatom fossils, and lithological changes. These lines of evidence indicate that the base of the 1953 layer is the best GSSP level candidate in the stratigraphy at this site.
• Geological controls on dispersal and deposition of river flood sediments on the Hidaka shelf, Northern Japan
  Ken Ikehara; Hajime Katayama; Tsumoru Sagayama; Tomohisa Irino
  Geological Society, London, Special Publications, SP505, 2019, Geological Society of London, 06 Sep. 2022, [Peer-reviewed]
  Scientific journal
• Benthic foraminifera in the Nakdong River Delta (southeast Korea) and their response to middle Holocene climatic change in the coastal environment of the East Asian margin
  Hiroyuki Takata; Tomohisa Irino; Kota Katsuki; Han Jun Woo; Jun-Ho Lee; Hyoun Soo Lim; Sangbeom Ha; Boo-Keun Khim
  Journal of Asian Earth Sciences, Aug. 2022
  Scientific journal
• Aleutian Low variability for the last 7500 years and its relation to the Westerly Jet
  Kana Nagashima; Jason Addison; Tomohisa Irino; Takayuki Omori; Kei Yoshimura; Naomi Harada
  Quaternary Research, 108, 161, 179, Cambridge University Press (CUP), Jul. 2022, [Peer-reviewed]
  English, Scientific journal, Abstract
  
  The Aleutian Low (AL) is one of the major atmospheric systems that determines environmental conditions during winter in the North Pacific Ocean, with impacts that affect the climates of both Asia and North America from mid- to high latitudes. However, the multi-centennial and longer scale behavior of the AL during the Holocene is not fully understood. In this study, AL variability since 7.5 ka was examined by applying the principal component analysis technique to published δ¹⁸O data derived from sedimentary calcite, peat, ice, and speleothem from western North America. The extracted Principal Component 1 (PC1) represents a dramatic change from the mid- to late Holocene, and appears to reflect long-term intensified AL related to interactions between orbitally-driven southward shift of the Westerly Jet (WJ) over East Asia and the northwestern Pacific, and intensification of the El Niño–Southern Oscillation. In contrast, PC2 is characterized by multi-centennial to millennial-scale oscillations, with a spatial loading pattern that suggests PC2 reflects AL intensity and position shifts. These oscillations are contemporaneous with both WJ latitude and/or the meandering path shifts over East Asia and solar activity change, suggesting that a decrease/increase in solar irradiance is related to AL variability via interactions with the WJ.
• Environmental evolution and fire history of Rebun Island (Northern Japan) during the past 17,000 years based on biomarkers and pyrogenic compound records from Lake Kushu
  Masanobu Yamamoto; Fangxian Wang; Tomohisa Irino; Kazuyoshi Yamada; Tsuyoshi Haraguchi; Hideto Nakamura; Katsuya Gotanda; Hitoshi Yonenobu; Christian Leipe; Xuan-Yu Chen; Pavel E. Tarasov
  QUATERNARY INTERNATIONAL, 623, 8, 18, Jun. 2022
  English, Scientific journal
• Late Holocene centennial to millennial-scale variability in lower trophic level productivity off southern Hokkaido, Japan, and its response to dissolved iron-replete Coastal Oyashio dynamics
  Michinobu Kuwae; Narumi Tsugeki; Bruce P. Finney; Yukinori Tani; Jonaotaro Onodera; Mako Kiyoto; Mitsukuni Kusaka; Takuya Sagawa; Yugo Nakamura; Hiroji Ohnishi; Hiroshi Kuroda; Noboru Okuda; Tamihisa Ohta; Minoru Ikehara; Tomohisa Irino
  Quaternary Research, 107, 1, 16, Cambridge University Press (CUP), 22 Feb. 2022
  Scientific journal, Abstract
  
  Little is known about the dynamics of marine food chains spanning primary to higher trophic levels on centennial and longer timescales, especially where the supply of dissolved iron limits primary productivity. To elucidate the long-term dynamics of biological productivity in the Coastal Oyashio (CO), which is a major pathway for transporting dissolved iron into the western North Pacific from winter to spring, we reconstructed the lower trophic level productivity over the last 3000 years in the CO. Our results demonstrate that the concentrations and mass accumulation rates of both Chl-a (chlorophyll a and its derivatives) and biogenic opal used as proxies of primary productivity, and steryl chlorin esters (SCEs) used as that of zooplankton productivity, show a millennial-scale increasing trend and centennial-scale variability beginning ca. AD 400. SCEs were positively correlated with Chl-a, indicating that changes in zooplankton productivity were induced by bottom-up control of primary productivity. The Chl-a and SCEs showed synchronous centennial-scale patterns with a relative abundance of sea-ice-associated diatom species transported by CO, and with a ventilation index in the Okhotsk Sea Intermediate Water. This synchronous pattern indicates that lower trophic-level productivity during the spring bloom responded to the intensity of iron-replete CO.
• Orbital-scale vegetation-ocean-atmosphere linkages in western Japan during the last 550 ka based on a pollen record from the IODP site U1427 in the Japan Sea
  Ryoma Hayashi; Takuya Sagawa; Tomohisa Irino; Ryuji Tada
  Quaternary Science Reviews, 267, 107103, 107103, Elsevier {BV}, Sep. 2021, [Peer-reviewed]
  Scientific journal
• A Lacustrine Biomarker Record From Rebun Island Reveals a Warm Summer Climate in Northern Japan During the Early Middle Holocene Due to a Stronger North Pacific High
  Masanobu Yamamoto; Fangxian Wang; Tomohisa Irino; Kenta Suzuki; Kazuyoshi Yamada; Tsuyoshi Haraguchi; Katsuya Gotanda; Hitoshi Yonenobu; Xuan-Yu Chen; Pavel Tarasov
  FRONTIERS IN EARTH SCIENCE, 9, Jun. 2021, [Peer-reviewed]
  English, Scientific journal
• Variations in sediment lithology of submarine flood deposits on the slope off Kumano River, Japan
  Ken Ikehara; Kazuko Usami; Tomohisa Irino
  Geological Society, London, Special Publications, SP501, 2019, Geological Society of London, 07 Jan. 2021, [Peer-reviewed]
  Scientific journal
• The 2011 Tohoku-oki tsunami-induced sediment remobilization on the Sendai shelf, Japan, from a comparison of pre- and post-tsunami surface sediments
  Ikehara, K.; Irino, T.; Saito, Y.
  Scientific Reports, 11, 1, 2021
  Scientific journal
• Characteristics and distribution of the event deposits induced by the 2011 Tohoku-oki earthquake and tsunami offshore of Sanriku and Sendai, Japan
  Ken Ikehara; Kazuko Usami; Tomohisa Irino; Akiko Omura; Robert G. Jenkins; Juichiro Ashi
  Sedimentary Geology, 411, 105791, 105791, Elsevier BV, Jan. 2021, [Peer-reviewed]
  Scientific journal
• Provenance changes in fine detrital quartz in the inner shelf sediments of the East China Sea associated with shifts in the East Asian summer monsoon front during the last 6 kyrs
  Ke Wang; Ryuji Tada; Hongbo Zheng; Tomohisa Irino; Bin Zhou; Keita Saito
  Progress in Earth and Planetary Science, 7, 1, Springer, 01 Dec. 2020
  English, Scientific journal
• Intercomparison of XRF Core Scanning Results From Seven Labs and Approaches to Practical Calibration
  Ann G. Dunlea; Richard W. Murray; Ryuji Tada; Carlos A. Alvarez‐Zarikian; Chloe H. Anderson; Adrian Gilli; Liviu Giosan; Thomas Gorgas; Rick Hennekam; Tomohisa Irino; Masafumi Murayama; Larry C. Peterson; Gert‐Jan Reichart; Arisa Seki; Hongbo Zheng; Martin Ziegler
  Geochemistry, Geophysics, Geosystems, 21, 9, Sep. 2020, [Peer-reviewed]
  English, Scientific journal
• Cyclostratigraphy of the Late Miocene to Pliocene sediments at IODP sites U1425 and U1430 in the Japan Sea and paleoceanographic implications
  Shunsuke Kurokawa; Ryuji Tada; Kenji M. Matsuzaki; Tomohisa Irino; Lofi Johanna
  Progress in Earth and Planetary Science, 6, 1, 01 Dec. 2019
  Scientific journal
• Sources of atmospheric black carbon and related carbonaceous components at Rishiri Island, Japan: The roles of Siberian wildfires and of crop residue burning in China
  Chunmao Zhu; Yugo Kanaya; Hisayuki Yoshikawa-Inoue; Tomohisa Irino; Osamu Seki; Yasunori Tohjima
  Environmental Pollution, 247, 55, 63, Apr. 2019, [Peer-reviewed]
  English, Scientific journal
• Progress report of the project to specify the location and magnitude of the Australasian tektite impact event
  Tada Ryuji; Tada Toshihiro; Carling Paul; Songtham Wichanet; Le Xuen Thuyen; Kayama Masahiro; Chang Yu; Kurosawa Kosuke; Tajika Eiichi; Okada Makoto; Suganuma Yusuke; Irino Tomohisa; Kubota Yoshimi
  Annual Meeting of the Geological Society of Japan, 2019, 298, The Geological Society of Japan, 2019
  Japanese
• Construction of perfectly continuous records of physical properties for dark-light sediment sequences collected from the Japan Sea during Integrated Ocean Drilling Program Expedition 346 and their potential utilities as paleoceanographic studies
  Tomohisa Irino; Ryuji Tada; Ken Ikehara; Takuya Sagawa; Akinori Karasuda; Shunsuke Kurokawa; Arisa Seki; Song Lu
  Progress in Earth and Planetary Science, 5, 1, 23, 23, Dec. 2018, [Peer-reviewed]
  Scientific journal
• Phylogenetic diversity and distribution of bacterial and archaeal amoA genes in the East China Sea during spring
  Kataoka, Takafumi; Suzuki, Koji; Irino, Tomohisa; Yamamoto; Masanobu; Higashi, Seigo; Liu, Hongbin
  Archives of Microbiology, 200, 2, 2018, [Peer-reviewed]
  Scientific journal
• Integrated tephrostratigraphy and stable isotope stratigraphy in the Japan Sea and East China Sea using IODP Sites U1426, U1427, and U1429, Expedition 346 Asian Monsoon
  Sagawa, Takuya; Nagahashi, Yoshitaka; Satoguchi, Yasufumi; Holbourn, Ann; Itaki, Takuya; Gallagher; Stephen J.; Saavedra-Pellitero, Mariem; Ikehara, Ken; Irino, Tomohisa; Tada, Ryuji
  Progress in Earth and Planetary Science, 5, 1, 2018, [Peer-reviewed]
  Scientific journal
• High-resolution and high-precision correlation of dark and light layers in the Quaternary hemipelagic sediments of the Japan Sea recovered during IODP Expedition 346
  Tada, Ryuji; Irino, Tomohisa; Ikehara, Ken; Karasuda, Akinori; Sugisaki, Saiko; Xuan, Chuang; Sagawa, Takuya; Itaki, Takuya; Kubota, Yoshimi; Lu; Song; Seki, Arisa; Murray; Richard W.; Alvarez-Zarikian, Carlos; Anderson, William T.; Bassetti; Maria Angela; Brace; Bobbi J.; Clemens; Steven C.; da Costa Gurgel; Marcio H.; Dickens, Gerald R.; Dunlea, Ann G.; Gallagher; Stephen J.; Giosan, Liviu; Henderson; Andrew C. G.; Holbourn; Ann E.; Kinsley, Christopher W.; nd Lee; Gwang Soo; Lee; Kyung Eun; Lofi, Johanna; Lopes; Christina I. C. D.; Saavedra-Pellitero; Mariem; Peterson; Larry C.; Singh, Raj K.; Toucanne, Samuel; Wan, Shiming; Zheng, Hongbo; Ziegler, Martin
  Progress in Earth and Planetary Science, 5, 1, 2018, [Peer-reviewed]
  Scientific journal
• Fluctuations in the East Asian monsoon recorded by pollen assemblages in sediments from the Japan Sea off the southwestern coast of Hokkaido, Japan, from 4.3 Ma to the present
  Igarashi, Y.; Irino, T.; Sawada, K.; Song, L.; Furota, S.
  Global and Planetary Change, 163, 2018, [Peer-reviewed]
  Scientific journal
• Evidence for surface sediment remobilization by earthquakes in the Nankai forearc region from sedimentary records
  Okutsu, Natsumi; Ashi, Juichiro; Yamaguchi, Asuka; Irino, Tomohisa; Ikehara, Ken; Kanamatsu, Toshiya; Suganuma, Yusuke; Murayama, Masafumi; Lintern, D. G.; Campbell, P. T.
  Subaqueous Mass Movements. Geological Society, 477, 2018, [Peer-reviewed]
  Scientific journal
• Depositional ages and characteristics of Middle-Upper Jurassic and Lower Cretaceous lacustrine deposits in southeastern Mongolia
  Hasegawa, Hitoshi; Ando, Hisao; Hasebe, Noriko; Ichinnorov; Niiden; Ohta, Tohru; Hasegawa, Takashi; Yamamoto; Masanobu; Li, Gang; Erdenetsog; Bat-Orshikh; Heimhofer, Ulrich; Murata, Takayuki; Shinya, Hironori; Enerel, G.; Oyunjargal, G.; Munkhtsetseg, O.; Suzuki, Noriyuki; Irino, Tomohisa; Yamamoto, Koshi
  Island Arc, December 2015, 2018, [Peer-reviewed]
  Scientific journal
• Biomass burning history in East Asia during the last 4 million years recorded in elemental carbon variability at IODP site U1423
  Lu, Song; Irino, Tomohisa; Igarashi, Yaeko
  Progress in Earth and Planetary Science, 5, 1, 2018, [Peer-reviewed]
  Scientific journal
• Characteristics of shallow marine flood sediments by organic carbon analyses, examples from shelf sediments off Hidaka, southern Hokkaido, after the 2003 typhoon no.10
  大村亜希子; 大村亜希子; 池原研; 片山肇; 入野智久; 嵯峨山積; 嵯峨山積
  地質学雑誌, 123, 5, 321‐333, 333, The Geological Society of Japan, May 2017, [Peer-reviewed]
  Japanese,

  We conducted an organic carbon analysis of flood sediments from the 2003 typhoon no. 10 off Hidaka, southern Hokkaido. Flood-induced sediments from the river mouth, inner shelf, outer shelf, and upper slope are rich in terrigenous organic carbon. Four years after the typhoon, flood sediments were found preserved in a topographic depression on the inner shelf, within an area protected from waves and currents. Stratigraphic variations in terrigenous organic carbon ratios in flood sediments from the depression reflect changes in river discharge with rainfall during the flood. Our results indicate that terrigenous material from the river mouth was continuously supplied and deposited on the shelf. These stratigraphic variations in the terrigenous organic carbon ratio could be significant in ongoing attempts to discriminate flood sediments from ancient turbidite successions.

• Holocene dynamics in the Bering Strait inflow to the Arctic and the Beaufort Gyre circulation based on sedimentary records from the Chukchi Sea
  Masanobu Yamamoto; Seung-Il Nam; Leonid Polyak; Daisuke Kobayashi; Kenta Suzuki; Tomohisa Irino; Koji Shimada
  Climate of the Past, 13, 9, 1111, 1127, 24 Apr. 2017, [Peer-reviewed]
  Scientific journal
• Detrital provenance of the Holocene sediments of the Beppu Bay based on mineral composition
  Irino Tomohisa; Maruyama Airi; Ikehara Ken; Yamamoto Masanobu; Kuwae Michinobu; Takemura Keiji
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 64, 16, 16, GEOCHEMICAL SOCIETY OF JAPAN, 2017
  Japanese,

• The ACER pollen and charcoal database: a global resource to document vegetation and fire response to abrupt climate changes during the last glacial period
  Goni; Maria Fernanda Sanchez; Despra; Stephanie; Daniau; Anne-Laure; Bassino; Frank C.; Polanco-Martinez; Josue M.; Harrison; Sandy P.; Allen, Judy R. M.; Anderson; R. Sco; Behling, Hermann; Bonnefille; Raymonde; Burjachs, Francesc; Carrion, Jose S.; Cheddadi, Rachid; Clark, James S.; Combourieu-Nebout, Nathalie; Mustaphi; Colin J. Courtney; Debusk; Georg H.; Dupon; Lydie M.; Finch; Jemma M.; Fletcher, William J.; Giardini, Marco; Gonzalez, Catalina; Gosling, William D.; Grigg, Laurie D.; Grimm; Eric C.; Hayashi, Ryoma; Helmens, Karin; Heusser; Linda E.; Hill, Trevor; Hope, Geoffrey; Huntley, Brian; Igarashi, Yaeko; Irino, Tomohisa; Jacobs, Bonnie; Jimenez-Moreno, Gonzalo; Kawai, Sayuri; Kershaw; A. Peter; Kumon, Fujio; Lawson; Ian T.; Ledru, Marie-Pierre; Lezine; Anne-Marie; Liew; Ping Mei; Magri, Donatella; Marchant, Rober; Margari, Vasiliki; Mayle; Francis E.; McKenzie; G. Merna; Moss, Patrick; Mueller, Stefanie; Mueller; Ulrich C.; Naughton, Filipa; Newnham; Rewi M.; Oba, Tadamichi; Perez-Obiol, Ramon; Pini, Roberta; Ravazzi, Cesare; Roucoux; Katy H.; Rucina; Stephen M.; Scott, Louis; Takahara, Hikaru; Tzedakis; Polichronis C.; Urrego, Dunia H.; van Geel, Bas; Valencia; B. Guido; Vandergoes; Marcus J.; Vincens, Annie; Whitlock; Cathy L.; Willard; Debra A.; Yamamoto; Masanobu
  Earth System Science Data, 9, 2, 2017, [Peer-reviewed]
  Scientific journal
• Origin of the water-soluble organic nitrogen in the maritime aerosol
  Matsumoto, Kiyoshi; Yamamoto, Yuya; Nishizawa, Kotaro; Kaneyasu, Naoki; Irino, Tomohisa; Yoshikawa-Inoue, Hisayuki
  Atmospheric Environment, 167, 2017, [Peer-reviewed]
  Scientific journal
• Multidecadal, centennial, and millennial variability in sardine and anchovy abundances in the western North Pacific and climate-fish linkages during the late Holocene
  Kuwae, Michinobu; Yamamoto; Masanobu; Sagawa, Takuya; Ikehara, Ken; Irino, Tomohisa; Takemura, Keiji; Takeoka, Hidetaka; Sugimoto; Takashige
  Progress in Oceanography, 159, 2017, [Peer-reviewed]
  Scientific journal
• Estimation of Evolutionary Rates of Mitochondrial DNA in Two Japanese Wood Mouse Species Based on Calibrations with Quaternary Environmental Changes
  Hanazaki, Kaori; Tomozawa; Morihiko; Suzuki, Yutaro; Kinoshita, Gohta; Yamamoto; Masanobu; Irino, Tomohisa; Suzuki, Hitoshi
  Zoological Science, 34, 3, 2017, [Peer-reviewed]
  Scientific journal
• ESR signal intensity of quartz in the fine-silt fraction of riverbed sediments from the Yangtze River: a provenance tracer for suspended particulate matter
  Saito, Keita; Tada, Ryuji; Zheng, Hongbo; Irino, Tomohisa; Luo, Chao; He, Mengying; Wang, Ke; Suzuki, Yoshiaki
  Progress in Earth and Planetary Science, 4, 2017, [Peer-reviewed]
  Scientific journal
• Palaeobotanical records from Rebun Island and their potential for improving the chronological control and understanding human-environment interactions in the Hokkaido Region, Japan
  Mueller, Stefanie; Schmidt, Mareike; Kossler, Annette; Leipe, Christian; Irino, Tomohisa; Yamamoto; Masanobu; Yonenobu, Hitoshi; Goslar, Tomasz; Kato, Hirofumi; Wagner; Mayke; Weber; Andrzej W.; Tarasov; Pavel E.
  Holocene, 26, 10, 2016, [Peer-reviewed]
  Scientific journal
• Mass accumulation rate of detrital materials in Lake Suigetsu as a potential proxy for heavy precipitation: a comparison of the observational precipitation and sedimentary record
  Suzuki, Yoshiaki; Tada, Ryuji; Yamada, Kazuyoshi; Irino, Tomohisa; Nagashima, Kana; Nakagawa, Takeshi; Omori, Takayuki
  Progress in Earth and Planetary Science, 3, 2016, [Peer-reviewed]
  Scientific journal
• Documenting large earthquakes similar to the 2011 Tohoku-oki earthquake from sediments deposited in the Japan Trench over the past 1500 years
  Ikehara, Ken; Kanamatsu, Toshiya; Nagahashi; Yoshitaka a; Strasser, Michael; Fink, Hiske; Usami, Kazuko; Irino, Tomohisa; Wefer, Gerold
  Earth and Planetary Science Letters, 445, 2016, [Peer-reviewed]
  Scientific journal
• Distribution of detrital minerals and sediment color in western Arctic Ocean and northern Bering Sea sediments: Changes in the provenance of western Arctic Ocean sediments since the last glacial period
  Kobayashi, Daisuke; Yamamoto; Masanobu; Irino, Tomohisa; Nam, Seung-Il; Park; Yu-Hyeon; Harada, Naomi; Nagashima, Kana; Chikita, Kazuhisa; Saitoh; Sei-Ichi
  Polar Science, 10, 4, 2016, [Peer-reviewed]
  Scientific journal
• Asian dust transport during the last century recorded in Lake Suigetsu sediments
  Nagashima, Kana; Suzuki, Yoshiaki; Irino, Tomohisa; Nakagawa, Takeshi; Tada, Ryuji; Hara, Yukari; Yamada, Kazuyoshi; Kurosaki, Yasunori
  Geophysical Research Letters, 43, 6, 2016, [Peer-reviewed]
  Scientific journal
• Expedition 346 summary
  R. Tada; R.W. Murray; C.A. Alvarez Zarikian; W.T. Jr. Anderson; M.-A. Bassetti; B.J. Brace; S.C. Clemens; M.H. da Costa Gurgel; G.R. Dickens; A.G. Dunlea; S.J. Gallagher; L. Giosan; A.C.G. Henderson; A.E. Holbourn; K. Ikehara; T. Irino; T. Itaki; A. Karasuda; C.W. Kinsley; Y. Kubota; G.S. Lee; K.E. Lee; J. Lofi; C.I.C.D. Lopes; L.C. Peterson; M. Saavedra-Pellitero; T. Sagawa; R.K. Singh; S. Sugisaki; S. Toucanne; S. Wan; C. Xuan; H. Zheng; M. Ziegler
  Proceedings of the IODP, Integrated Ocean Drilling Program, 28 Mar. 2015
  In book
• The reports on the session "A-HW27 Water and material transport and cycle in watersheds: from headwater to coastal area" in JPGU2015
  YOSHIKAWA Seiko; KOBAYASHI Masahiro; SAITO Mitsuyo; NAKAYA Shinji; ONODERA Shinichi; OKUDA Noboru; CHIKITA Kazuhisa; IRINO Tomohisa
  Japanese Journal of Soil Science and Plant Nutrition, 86, 6, 592, 594, Japanese Society of Soil Science and Plant Nutrition, 2015
  Japanese
• Terrestrial plant biomarkers analyses in a sediment core from Japan Sea off Hokkaido (IODP Exp.346 U1423 site)
  Aoyagi Chiaki; Sawada Ken; Furota Satoshi; Irino Tomohisa; Igarashi Yaeko
  Annual Meeting of the Geological Society of Japan, 2015, 195, 195, The Geological Society of Japan, 2015
• Temporal variations in black carbon recorded on Rishiri Island, northern Japan
  Zhu, Chunmao; Yoshikawa-Inoue, Hisayuki; Tohjima, Yasunori; Irino, Tomohisa
  Geochemical Journal, 49, 3, 2015, [Peer-reviewed]
  Scientific journal
• Ozone depletion in the interstitial air of the seasonal snowpack in northern Japan
  Nakayama, Momoko; Zhu, Chunmao; Hirokawa, Jun; Irino, Tomohisa; Yoshikawa-Inoue, Hisayuki
  Tellus Series B-Chemical and Physical Meteorology, 67, 2015, [Peer-reviewed]
  Scientific journal
• OSL dating of fine-grained quartz from Holocene Yangtze delta sediments
  Sugisaki, Saiko; Buylaert, Jan-Pieter; Murray, Andrew; Tada, Ryuji; Zheng, Hongbo; Ke, Wang; Saito, Keita; Chao, Luo; Li, Shiyi; Irino, Tomohisa
  Quaternary Geochronology, 30, 2015, [Peer-reviewed]
  Scientific journal
• Possible submarine tsunami deposits on the outer shelf of Sendai Bay, Japan resulting from the 2011 earthquake and tsunami off the Pacific coast of Tohoku
  Ken Ikehara; Tomohisa Irino; Kazuko Usami; Robert Jenkins; Akiko Omura; Juichiro Ashi
  Marine Geology, 358, 120, 127, Dec. 2014, [Peer-reviewed]
  Scientific journal
• Distribution, source and transportation of glycerol dialkyl glycerol tetraethers in surface sediments from the western Arctic Ocean and the northern Bering Sea
  Park, Y.-H.; Yamamoto, M.; Nam, S.-I.; Irino, T.; Polyak, L.; Harada, N.; Nagashima, K.; Khim, B.-K.; Chikita, K.; Saitoh, S.-I.
  Marine Chemistry, 165, 2014, [Peer-reviewed]
  Scientific journal
• Tracing Sr isotopic composition in space and time across the Yangtze River basin
  Luo, Chao; Zheng, Hongbo; Tada, Ryuji; Wu, Weihua; Irino, Tomohisa; Yang, Shouye; Saito, Keita
  Chemical Geology, 388, 2014, [Peer-reviewed]
  Scientific journal
• Nutricline shoaling in the eastern Pacific warm pool during the last two glacial maxima
  Bin Shaari; Hasrizal; Yamamoto; Masanobu; Irino, Tomohisa; Oba, Tadamichi
  Journal of Oceanography, 70, 1, 2014, [Peer-reviewed]
  Scientific journal
• Millennial-scale East Asian Summer Monsoon variability recorded in grain size and provenance of mud belt sediments on the inner shelf of the East China Sea during mid-to late Holocene
  Wang, Ke; Zheng, Hongbo; Tada, Ryuji; Irino, Tomohisa; Zheng, Yan; Saito, Keita; Karasuda, Akinori
  Quaternary International, 349, 2014, [Peer-reviewed]
  Scientific journal
• Dynamics of the turbidity current generated by the 2011 Tohoku-Oki earthquake and tsunami
  Arai Kazuno; Naruse Hajime; Kawamura Kiichiro; Irino Tomohisa; Ikehara Ken; Saitoh Yu; Murayama Masafumi; Miura Ryo; Hino Ryota; Ito Yoshihiro; Inazu Daisuke; Yokokawa Miwa; Izumi Norihiro
  Annual Meeting of the Geological Society of Japan, 2013, 042, The Geological Society of Japan, 2013
• 日本の亜熱帯域と温帯域におけるキクメイシ Dipsastraea speciosa （ Dana , 1846 ） の骨格成長
  永田, 俊輔; 杉浦, 薫; 入野, 智久; 渡邊, 剛; 山野, 博哉
  日本サンゴ礁学会誌, 15, 37, 56, 日本サンゴ礁学会, 2013, [Peer-reviewed]
  Japanese, Scientific journal
• Stratigraphy and wiggle-matching-based age-depth model of late Holocene marine sediments in Beppu Bay, southwest Japan
  Kuwae, Michinobu; Yamamoto; Masanobu; Ikehara, Ken; Irino, Tomohisa; Takemura, Keiji; Sagawa, Takuya; Sakamoto, Tatsuhiko; Ikehara; Minoru; Takeoka, Hidetaka
  Journal of Asian Earth Sciences, 69, 2013, [Peer-reviewed]
  Scientific journal
• Seasonal variations in planktonic foraminiferal flux and oxygen isotopic composition in the western North Pacific: Implications for paleoceanographic reconstruction
  Sagawa, Takuya; Kuroyanagi, Azumi; Irino, Tomohisa; Kuwae, Michinobu; Kawahata, Hodaka
  Marine Micropaleontology, 100, 11, 20, 2013, [Peer-reviewed]
  English, Scientific journal
• Evidence of recent warming in the Okinawa region, subtropical northwestern Pacific, from an oxygen isotope record of a cave-dwelling marine micro-bivalve
  Kitamura, Akihisa; Kobayashi; Konatsu; Tamaki, Chikako; Yamamoto, Nagisa; Irino, Tomohisa; Miyairi, Yosuke; Yokoyama, Yusuke
  Paleontological Research, 17, 1, 2013, [Peer-reviewed]
  Scientific journal
• Enhanced upwelling in the eastern equatorial Pacific at the last five glacial terminations
  bin Shaari; Hasrizal; Yamamoto; Masanobu; Irino, Tomohisa
  Palaeogeography Palaeoclimatology Palaeoecology, 386, 2013, [Peer-reviewed]
  Scientific journal
• Variabilities in detrital supply and the marine environment at ODP Site 1237 in the southeast Pacific Ocean since the late Oligocene.
  Noma Eriko; Irino Tomohisa; Shaari Hasrizal; Yamamoto Masanobu
  Annual Meeting of the Geological Society of Japan, 2012, 214, 214, The Geological Society of Japan, 2012
• Relationship between mineral and major element compositions of suspended materials of the Saru River, Hokkaido, and marine sediments at its river mouth
  Irino Tomohisa; Yamashita Yohei; Seki Osamu; Ikehara Ken; Nagao Seiya
  Annual Meeting of the Geological Society of Japan, 2012, 220, 220, The Geological Society of Japan, 2012
• Sea level at the last glacial maximum, constrained by oxygen isotopic curves of planktonic foraminifera in the Japan Sea
  Oba, Tadamichi; Irino, Tomohisa
  Journal of Quaternary Science, 27, 9, 2012, [Peer-reviewed]
  Scientific journal
• Orbital- and millennial-scale paleoceanographic changes in the north-eastern Japan Basin, East Sea/Japan Sea during the late Quaternary
  Khim, Boo-Keun; Ikehara, Ken; Irino, Tomohisa
  Journal of Quaternary Science, 27, 3, 2012, [Peer-reviewed]
  Scientific journal
• Distribution of glycerol dialkyl glycerol tetraethers, alkenones and polyunsaturated fatty acids in suspended particulate organic matter in the East China Sea
  Nakanishi, Takahiro; Yamamoto; Masanobu; Irino, Tomohisa; Tada, Ryuji
  Journal of Oceanography, 68, 6, 2012, [Peer-reviewed]
  Scientific journal
• The variability of ozone in the interstitial air of seasonal snow-pack on Rishiri Island.
  nakayama momoko; yoshikawa hisayuki; jun hirokawa; irino tomohisa; kodama yuji; tanimoto hiroshi
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 58, 31, 31, GEOCHEMICAL SOCIETY OF JAPAN, 2011
  温室効果気体であるオゾンは二酸化炭素、メタンに次いで3番目に地球温暖化に寄与する気体である。そのため全球のオゾン濃度を把握することやオゾンの吸収源と放出源を把握することが重要である。積雪内でオゾンが分解され、積雪がオゾンの吸収源になり得るという研究が近年盛んに行われるようになってきた。本研究は中緯度地域にある季節雪氷域である北海道・利尻島で積雪内間隙空気中オゾン濃度及び大気中オゾン濃度を計測し、利尻島の積雪がオゾンの吸収源になり得るか調べると同時に、積雪内で起こるオゾン分解反応のメカニズムと反応速度について調べた。
• Relationship between the Andean volcanism and paleoclimatic /paleoceanographic changes based on ODP Site 1237 core
  Irino Tomohisa; Yamamoto Masanobu
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 58, 110, 110, GEOCHEMICAL SOCIETY OF JAPAN, 2011
  新生代における山地の隆起と気候変動の関係を検討するために、ペルー沖ODP Site 1237コアの鉱物・化学組成を検討する。特に堆積物コアに含まれる中央アンデス起源と思われる火山灰の寄与と砕屑物および海洋炭酸塩組成の分析を通して、この地域の長い時間スケールの火山活動と気候・海洋変動との間の関係を解析することを目的とした。コアは前期漸新世までおよんでおり、4 Maまでは95%以上が炭酸塩の軟泥である。砕屑鉱物組成が検討できた2.5 Ma以降では、火山活動の活発化に遅れて乾燥化が起こることが示唆された。
• Meridional Sea Surface Temperature Evolution in the Eastern Tropical Pacific during the Last Glacial Cycles
  bin Shaari Hasrizal; Yamamoto Masanobu; Irino Tomohisa
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 58, 144, 144, GEOCHEMICAL SOCIETY OF JAPAN, 2011
  ODPサイト1237, 1239, 1241の堆積物に含まれるグリセロール・ジアルキル・グリセロール・テトラエーテルを分析することにより過去１５万年間のTEX86古水温変動を求め，水温の緯度勾配の変化を検討した．
• Winter monsoon variability during the last 40,000 years; evidence from TEX86-derived temperatures in the northern East China Sea
  Yamamoto Masanobu; Nakanishi Takahiro; Kishizaki Midori; Irino Tomohisa; Tada Ryuji; Oda Hirokuni
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 58, 142, 142, GEOCHEMICAL SOCIETY OF JAPAN, 2011
  We discuss winter monsoon variability during the last 40,000 years, based on TEX86-derived temperature records from cores MD98-2195, KY0704 PC-1, and KY0704 PL-1 retrieved from the northern East China Sea.
• SPATIAL DISTRIBUTION OF Delta C-14 VALUES OF ORGANIC MATTER IN SURFACE SEDIMENTS OFF SARU RIVER IN NORTHERN JAPAN, ONE YEAR AFTER A FLOOD EVENT IN 2006
  Nagao, Seiya; Irino, Tomohisa; Aramaki, Takafumi; Ikehara, Ken; Katayama, Hajime; Otosaka, Shigeyoshi; Uchida, Masao; Shibata, Yasuyuki
  Radiocarbon, 52, 3, 1068, 1077, 2010, [Peer-reviewed]
  English, Scientific journal
• Millennial-scale variability in vegetation records from the East Asian Islands: Taiwan, Japan and Sakhalin
  Takahara, Hikaru; Igarashi, Yaeko; Hayashi, Ryoma; Kumon, Fujio; Liew; Ping-Mei; Yamamoto; Masanobu; Kawai, Sayuri; Oba, Tadamichi; Irino, Tomohisa
  Quaternary Science Reviews, 29, 21-22, 2010, [Peer-reviewed]
  Scientific journal
• Climatic and hydrologic variability in the East China Sea during the last 7000 years based on oxygen isotope records of the submarine cavernicolous micro-bivalve Carditella iejimensis
  Yamamoto, Nagisa; Kitamura, Akihisa; Irino, Tomohisa; Kase, Tomoki; Ohashi, Syu-ichi
  Global and Planetary Change, 72, 3, 2010, [Peer-reviewed]
  Scientific journal
• Investigation on coral necrosis in massive Porites colony in the Mouth of Todoroki river, Ishigaki Island, Japan deduced from the δ^O, δ^C and Mn/Ca ratios
  KAWASHIMA Tatsunori; WATANABE Tsuyoshi; SHIRAI Kotaro; MAEKAWA Satoshi; SHIMAMURA Michiyo; IRINO Tomohisa; SANO Yuji
  Chikyukagaku, 43, 1, 35, 42, The Geochemical Society of Japan, 30 Mar. 2009, [Peer-reviewed]
  Japanese, Coral reefs are increasingly faced to the crisis of decline and death caused by climate changes and anthropogenic influence. These crises were reported in Shiraho coral reefs, the Ishigaki Island, Southwestern Japan, caused by the red soils runoff through the Todoroki River. In order to evaluate the influence of terrestrial inputs on coral skeletal growth and coral death, we have analyzed oxygen and carbon isotopic ratios, as well as Mn/Ca ratio, of coral Porites, skeleton collected from Shiraho reef. The coral colony used in this study was still alive but partly dead when the samples were ...
• 北限サンゴ礁から採取されたキクメイシ属サンゴ骨格中の 酸素・炭素同位体比 -中緯度域における高時間分解能古気候アーカイブとしての検討-
  島村 道代; ヒョン キソン; 渡邊 剛; ソ インア; ユ チャンミン; 入野 智久; 杉原 薫; 山野 博哉
  日本地球化学会年会要旨集, 56, 29, 29, 日本地球化学会, 2009
  Japanese, 世界で最も高緯度に位置する、日本の壱岐サンゴ礁より採取されたキクメイシ属サンゴ骨中の酸素・炭素同位体比を分析し、中緯度域における高時間分解能古気候アーカイブとしての可能性を検討した。まず試料は莢壁と軸柱の骨格構造別に分析し、その結果を生育時の環境記録と対比・検討を行った。この結果、軸柱と莢壁は形成のタイミングが異なっており、キクメイシ属サンゴの場合、莢壁の方がより正確に環境を記録することがわかった。また本研究で用いたサンゴ骨格は、骨格構造自体にも成長パターンの季節的変化が見られた。これらの成果を基に、さらに長期に渡る骨格分析を行い、これらを周辺の環境と対比・検討したのでその成果を報告する。
• Geochemical perspective on coral skeletal growth of temperate Porites and Favia
  Kawamura Takashi; Watanabe Tsuyoshi; Sowa Kohki; Sakamoto Tatsuhiko; Irino Tomohisa; Shimamura Michiyo; Hyeong Kiseong; Sugihara Kaoru; Yamano Hiroya
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 56, 25, 25, GEOCHEMICAL SOCIETY OF JAPAN, 2009
  造礁性サンゴ骨格を用いた古環境復元においては、これまで塊状の群体を形成するハマサンゴ属が主に用いられてきた。キクメイシ属の塊状群体は、ハマサンゴ属のそれよりもさらに高緯度の地域でみられることから、ハマサンゴ属よりも低水温に適応していると考えられている。したがってキクメイシ属の骨格は、従来造礁性サンゴ骨格があまりターゲットにしてこなかった温帯地域での古環境指標として広く利用できる可能性を秘めている。鹿児島県甑島は温帯性の気候帯に属し、ハマサンゴ属とキクメイシ属がどちらも生息している。本研究では、甑島産のハマサンゴとキクメイシの軟X線画像による密度バンドと骨格中の酸素安定同位体比を用いて、両種のサンゴの温帯地域における骨格成長の季節性と、古水温指標としての可能性を比較・検討した。
• 太平洋中層での浮遊性有孔虫殻の溶解と二次石灰化およびその同位体比への影響
  入野 智久; 太田 晴美; 大場 忠道
  日本地球化学会年会要旨集, 56, 128, 128, 日本地球化学会, 2009
  Japanese, 氷期-間氷期サイクルに伴う大気中CO2濃度の変動には、海洋の炭素循環が大きな役割を果たしていることは確かであるが、炭酸塩の保存・溶解がどの程度寄与しているかを定量的に言うことは依然として難しい。また太平洋は大きいので炭素収支への寄与も大きいことは確かだが、海盆全体が深いことととCCDが浅いことのために、中層での炭酸塩保存・溶解が十分には評価されてきていない。そこで本研究では、日本南岸の外洋域において、海洋表層に死骸で浮遊していたもの・セディメントトラップで回収された水柱を沈降中のもの・表層堆積物の３通りの試料から浮遊性有孔虫Globigerinoides sacculiferの完全個体を50-70個ずつ集め、そのサイズ・重量・酸素炭素安定同位体比を一個体ずつについて分析することを通して、浮遊性有孔虫殻の重量変化過程を明らかにするとともに、過去の溶解程度の変動とその同位体比への影響を検討した。
• The 1500-year climate oscillation in the midlatitude North Pacific during the Holocene
  Isono, Dai; Yamamoto; Masanobu; Irino, Tomohisa; Oba, Tadamichi; Murayama, Masafumi; Nakamura, Toshio; Kawahata, Hodaka
  Geology, 37, 7, 2009, [Peer-reviewed]
  Scientific journal
• Holocene temperature change in the northern East China Sea
  Nakanishi Takahiro; Yamamoto Masanobu; Okino Tatsufumi; Irino Tomohisa; Oda Hirokuni; Yokoyama Yusuke; Matsuzaki Hiroyuki; Tada Ryuji
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 55, 414, 414, GEOCHEMICAL SOCIETY OF JAPAN, 2008
  KY07-04航海により採取されたピストンコアPC-1とマルチプルコアPL-1を使用して、東シナ海北部の過去5000年間の表層水温を、バイオマーカー指標であるアルケノンに基づくU^K₃₇'とGDGT指標であるTEX₈₆を用いて、40年から80年間隔と時間的解像度を高めて水温変動を復元した。アルケノン水温は過去5000年間に渡って23.5℃から24℃とほぼ一定の値を示した。一方、TEX₈₆水温はアルケノン水温とは異なり、20.4℃から24.8℃の間で激しく変動した。両者の水温変動に違いが見られる理由として、それぞれの物質をつくる生物の生息時期や深度の違いが挙げられるが、GDGTをつくるクレンアーキオータの生息深度は不明である。これを解決する手段として、本年５月に行われたKT08-10航海にてコアサイト付近の表層から中層の海水を採取し、ろ過後脂質を抽出し、GDGTを分析した。発表では、海水より求めたTEX₈₆水温の結果も合わせて報告する。
• Development of non-destructive and expeditious analysis of coral skeleton for reconstructing paleo-environment ; Coral skeletal growth from digitized images of X-radiographs and chemical compositional variants from Non-Destructive X-Ray Fluorescence
  SOWA KOHKI; WATANABE TSUYOSHI; SAKAMOTO TATSUHIKO; IJIMA KOHICHI; TAKASAWA MASAYOSHI; IRINO TOMOHISA; Aguilar Yolanda M.; KASE TOMOKI
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 55, 408, 408, GEOCHEMICAL SOCIETY OF JAPAN, 2008
  本研究では, 非破壊かつ迅速で簡便にサンゴ骨格成長量と俯瞰的な化学組成変動(数ヶ月程度の解像度での季節変動)を捉える分析手法を開発することが目的である。具体的には, 軟X線写真,非破壊蛍光X線地殻コアロガー・微少領域対応型（TATSCAN-F1）とコア対応型(TATSCAN-F2)を用いて, サンゴ骨格成長量と俯瞰的な化学組成変動を時系列に沿って分析する。本研究手法の確立により, 最大150cm長のサンゴコア(推定年齢150年程度)のサンゴ骨格成長量と俯瞰的な化学組成変動を, サンゴコアを数枚に切断することなく, 非破壊で数日以内に分析できる。本講演では, 我々がこれまで鋭意進めてきたそれらの手法の可能性と開発成果を報告する。
• Reconstruction of seasonal sea surface temperature variability in the Japan Sea during the Last Glacial Maximum based on oxygen isotope composition of bivalve
  Tada Keigo; Irino Tomohisa; Kitamura Akihisa; Ikehara Ken
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 55, 417, 417, GEOCHEMICAL SOCIETY OF JAPAN, 2008
  現在、東アジア東縁域は季節性のあるモンスーン域にあたる。モンスーン変動の仕組みを解明するためにはこのような季節性が過去にどうであったかを明らかにする必要がある。現在の日本海表層水はモンスーンの季節性を反映している。しかし、LGMは過去の研究から日本海表層水の低塩分化は確実であるが、水温変化については見解が一致していない。加えて、その情報はブルーミング時期に集中している。これらの問題点を克服するために、水温・塩分の連続的な季節変動を記録していると期待される二枚貝化石を用いてLGMの日本海表層の水温季節変動幅の復元を行った。得られた結果から対象とした二枚貝のうちPatinopecten yessoensisの年代は22112±112 cal yr BPでLGMにあたる。P. yessoensisのδ18Oは周期的な変動を示し、夏期にあたる最小値は0.7‰でありOba et al., (1991)のLGMにおける浮遊性有孔虫のδ18O値と一致していた。また、過去の研究では不明であった冬期の酸素同位体比の最大値は3.0‰であった。
• 鹿島沖海底コアMD01-2421の後期更新世テフラ層序
  青木, かおり; 入野; 智久; 大場, 忠道
  第四紀研究, 47, 6, 2008, [Peer-reviewed]
  Scientific journal
• Opposed trend of skeletal carbon isotopic ratios found in two different coral species collected from the same site: Genus-dependent responses
  Shimamura, Michiyo; Hyeong, K.; Watanabe, Tsuyoshi; Irino, Tomohisa; Yoo; Chan Min; Kim, W. S.
  Proc 11th Int Coral Reef Symp, 4, 2008, [Peer-reviewed]
  Scientific journal
• Reconstruction of paleotemperatures in the Northwest Pacific over the past 3000 years from delta(18)O values of the micro-bivalvia Carditella iejimensis found in a submarine cave
  Yamamoto, Nagisa; Kitamura, Akihisa; Irino, Tomohisa; Kase, Tomoki; Ohashi, Syu-ichi
  Global and Planetary Change, 62, 1-2, 2008, [Peer-reviewed]
  Scientific journal
• Main controlling factors of coral skeletal carbon isotopic composition and skeletal extension rate: High-resolution study at Hainan Island, South China Sea
  Shimamura, Michiyo; Irino, Tomohisa; Oba, Tadamichi; Xu, Guoqiang; Lu, Bingquan; Wang, Luejiang; Toyoda, Kazuhiro
  Geochemistry Geophysics Geosystems, 9, 2008, [Peer-reviewed]
  Scientific journal
• High resolution stable isotope records of sclreractinian corals near Ishigaki Island: Their implication as a potential paleoclimatic recorder in middle latitude regions
  Shimamura, Michiyo; Hyeong, Kiseong; Yoo; Chan Min an; Watanabe, Tsuyoshi; Irino, Tomohisa; Jung; Hoi-Soo
  Geosciences Journal, 12, 1, 2008, [Peer-reviewed]
  Scientific journal
• 北海道日高沖陸棚上における 2003 年洪水後の表層堆積物分布
  片山, 肇; 池原, 研; 菅; 和哉 an; 嵯峨山; 積; 入野; 智久; 辻野, 匠; 井上, 卓彦
  地質調査研究報告, 58, 2007
  Scientific journal
• Potential of submarine-cave sediments and oxygen isotope composition of cavernicolous micro-bivalve as a late Holocene paleoenvironmental record
  Kitamura, Akihisa; Yamamoto, Nagisa; Kase, Tomoki; Ohashi, Shu-ichi; Hiramoto, Mayumi; Fukusawa; Hitoshi an; Watanabe, Tsuyoshi; Irino, Tomohisa; Kojitani; Hiroshi; Shimamura, Michiyo; Kawakami, Ikuo
  Global and Planetary Change, 55, 4, 2007, [Peer-reviewed]
  Scientific journal
• Orbital-scale stratigraphy and high-resolution analysis of biogenic components and deep-water oxygenation conditions in the Japan Sea during the last 640 kyr
  Kido, Yoshiki; Minami, Ikue; Tada, Ryuji; Fujine, Kazuho; Irino, Tomohisa; Ikehara, Ken; Chun, Jong-Hwa
  Palaeogeography Palaeoclimatology Palaeoecology, 247, 1-2, 2007, [Peer-reviewed]
  Scientific journal
• Orbital- and millennial-scale variations in Asian dust transport path to the Japan Sea
  Nagashima, Kana; Tada, Ryuji; Matsui, Hiroyuki; Irino, Tomohisa; Tani, Atsushi; Toyoda, Shin
  Palaeogeography Palaeoclimatology Palaeoecology, 247, 1-2, 2007, [Peer-reviewed]
  Scientific journal
• Deep water ventilation in the northwestern North Pacific during the last deglaciation and the early Holocene (15-5 cal. kyr BP) based on AMS C-14 dating
  Minoshima, Kayo; Kawahata, Hodaka; Irino, Tomohisa; Ikehara, Ken; Aoki, Kaori; Uchida, Masao; Yoneda, Minoru; Shibata, Yasuyuki
  Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms, 259, 1, 2007, [Peer-reviewed]
  Scientific journal
• 堆積物から紐解く自然災害 2003年北海道日高洪水堆積物の海域における堆積様式
  池原研; 片山肇; 嵯峨山積; 菅和哉; 辻野匠; 入野智久; 大村亜希子
  月刊地球, 28, 8, 512, 517, 海洋出版, 01 Aug. 2006
  Japanese
• O-59 Evaluation of carbonate dissolution during last glacial maximum based on weight distribution of planktonic foraminifer
  Irino Tomohisa; Ota Harumi; Oba Tadamichi
  Annual Meeting of the Geological Society of Japan, 2006, 73, 73, The Geological Society of Japan, 2006
  Japanese
• Paleoenvironmental change off Kashima of central Japan during the last 144,000 years based on planktonic foraminiferal assemblage
  Niimura Yasushi; Irino Tomohisa; Oba Tadamichi
  Fossils, 79, 4, 17, Palaeontological Society of Japan, 2006
  Japanese, We reconstructed the oceanographic changes during the last 144 kyr off Kashima, central Japan, utilizing several planktonic foraminiferal species extracted from an IMAGES sediment core of 45.82m long (MD01-2421; 36°02'N latitude and 141°47'E longitude; water depth=2,224m). We proposed the results based on the temporal variation in Tf values, (ratio of warm water species)/(warm+cold water species), relative abundance of Neogloboquadrina pachyderma (Ehrenberg) (sinistral coiling), sea surface temperatures (SST) and the faunal similarity between the present core and the surface sediments along the Pacific side off the Japanese Islands together. These results suggest that the core site has experienced under the water mass condition similar to the present Oyashio Current off southeast Hokkaido (42-43°N) during the glacial maxima and the water mass similar to the present Kuroshio Current off south Kyushu to south coast of the Japanese Islands (31-33°N) during the interglacial maxima. The SST estimates at the core site using regional and global transfer functions indicate that the SSTs were lower by〜10℃ around the Last Glacial Maximum (LGM, in particular 19-18 ka) and Marine Isotope Stage (MIS) 6 maximum (135-129 ka) compared to the modern temperature, while the SSTs were higher by〜1℃ during mid-Holocene (8-7 ka) and at MIS 5a (77-76ka), MIS 5c (〜94 ka), MIS 5d (112-107 ka) and MIS 5e (122-119 ka). Most prominent changes off Kashima have occurred during the cold to warm transitions of MIS 6/5 and MIS 2/1, when the Oyashio Current occupied over the core site as well as during the LGM. However, the influence of the Kuroshio Current was more distinct during most of the last interglacial period (MIS-5) than today except short periods of MIS 5b (〜86 ka) and MIS 5d (〜115 ka).
• Paleoceanographic history around the Tsugaru Strait between the Japan Sea and the Northwest Pacific Ocean since 30 cal kyr BP
  Koizumi, Itaru; Tada, Ryuji; Narita, Hisashi; Irino, Tomohisa; Aramaki, Takafumi; Oba, Tadamichi; Yamamoto, Hirofumi
  Palaeogeography, Palaeoclimatology, Palaeoecology, 232, 1, 2006, [Peer-reviewed]
  Scientific journal
• Paleoceanographic change off central Japan since the last 144,000 years based on high-resolution oxygen and carbon isotope records
  Oba, Tadamichi; Irino, Tomohisa; Yamamoto; Masanobu; Murayama, Masafumi; Takamura, Akira; Aoki, Kaori
  Global and Planetary Change, 53, 1-2, 2006, [Peer-reviewed]
  Scientific journal
• Long term Aleutian Low dynamics and obliquity-controlled oceanic primary production in the mid-latitude western North Pacific (Core MD01-2421) during the last 145,000 years
  Ueshima, Toshinori; Yamamoto; Masanobu; Irino, Tomohisa; Oba, Tadamichi; Minagawa; Masao; Narita, Hisashi; Murayama, Masafumi
  Global and Planetary Change, 53, 1-2, 2006, [Peer-reviewed]
  Scientific journal
• Changes of primary production and ocean circulation off Sanriku in the northwestern Pacific over the last 27kyr
  Minoshima Kayo; Kawahata Hodaka; Irino Tomohisa; Ikehara Ken; Uchida Masao; Shibata Yasuyuki
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 52, 122, 122, GEOCHEMICAL SOCIETY OF JAPAN, 2005
  三陸沖は、親潮・津軽暖流・黒潮がぶつかり合い、多数の渦が形成される複雑な水塊構造をなす海域である。渦の中でも冷水渦は亜表層から表層に栄養塩を供給しており、この海域の高い生物生産を支えていると考えられる。最終氷期から現在にかけて親潮フロントの位置や黒潮流軸の変動、津軽海峡の閉鎖などが報告されており、海洋環境の変動が生物生産へ大きな影響を与えたと予想される。そこで三陸沖で取られたピストンコア試料を用いて、有機炭素量・オパール量・アルケノン量の測定を行い、過去2万7千年間にわたり生物生産がどのように変動していたかを、これまでの研究と併せて検討を行った。
• Southern migration of westerlies in the Northern Hemisphere PEP II transect during the Last Glacial Maximum
  Ono, Y.; Irino, T.
  Quaternary International, 118, 13, 22, 2004, [Peer-reviewed]
  Scientific journal
• Paleoceanography during the last 150 kyr off central Japan based on diatom floras
  Koizumi, I.; Irino, T.; Oba, T.
  Marine Micropaleontology, 53, 3-4, 2004, [Peer-reviewed]
  Scientific journal
• Lithology of pelagic sediment cores (PC-2,3,7) recovered from northwestern Pacific on R/V "Kairei" KR02-15 cruise.
  IRINO TOMOHISA; SAGAWA TAKUYA; NIIMURA YASUSHI; KANAMATSU TOSHIYA; YAMAZAKI TOSHITSUGU; MISHIMA TOSHIAKI
  JAMSTEC深海研究, 23, 121, 133, Dec. 2003
  Japanese
• High-resolution reconstruction of variation in aeolian dust (Kosa) deposition at ODP site 797, the Japan Sea, during the last 200 ka
  Irino, T.; Tada, R.
  Global and Planetary Change, 35, 1-2, 2003, [Peer-reviewed]
  Scientific journal
• High resolution records of organic carbon and its isotopes in Core MD01-2421 off central Japan, NW Pacific, during the last 145,000 years
  Ueshima, T.; Yamamoto, M.; Oba, T.; Kuramoto, T.; Minagawa, M.; Irino, T.
  Geochimica Et Cosmochimica Acta, 67, 18, 2003, [Peer-reviewed]
  Scientific journal
• Diatom record of the late Holocene in the Okhotsk Sea
  Koizumi, I.; Shiga, K.; Irino, T.; Ikehara, M.
  Marine Micropaleontology, 49, 1-2, 2003, [Peer-reviewed]
  Scientific journal
• 日本近海の長尺ピストンコアに見いだされたスープ状擾乱層
  山本, 正伸; 入野, 智久; 大場, 忠道; 村山, 雅史; 池原, 実; 小玉, 一人; 川幡, 穂高
  石油技術協会誌, 67, 6, 590, 593, 石油技術協会, 2002, [Peer-reviewed]
  Japanese, Scientific journal
• O-67 Temporal variations in aeolian dust flux and grain size based on elemental and grain size analyses of the Japan Sea sediments
  Irino T.; Tada R.; Matsui H.; Nagashima K.
  Annual Meeting of the Geological Society of Japan, 2000, 45, 45, The Geological Society of Japan, 2000
  Japanese
• O-180 Strong grain size dependence of organic carbon content in the fine-grained sediments deposited under the influence of bottom current
  多田 隆治; 入野 智久; 佐藤 宗平; 長島 佳菜
  Annual Meeting of the Geological Society of Japan, 2000, 101, 101, The Geological Society of Japan, 2000
  Japanese
• Quantification of aeolian dust (Kosa) contribution to the Japan Sea sediments and its variation during the last 200 ky
  Irino, T.; Tada, R.
  Geochemical Journal, 34, 1, 2000, [Peer-reviewed]
  Scientific journal
• Millennial-scale compositional variations in late Quaternary sediments at site 1017, Southern California
  Tada, R.; Sato, S.; Irino, T.; Matsui, H.; Kennett, J. P.
  Proceedings of the Ocean Drilling Program: Scientific Results, 167, 2000, [Peer-reviewed]
  Scientific journal
• Late Quaternary textural change offshore of point conception, site 1017, central California margin
  Behl, R. J.; Tada, R.; Irino, T.
  Proceedings of the Ocean Drilling Program: Scientific Results, 167, 2000, [Peer-reviewed]
  Scientific journal
• Geochemical character of glacial to interglacial sediments at site 1017, southern Californian margin: Minor and trace elements
  Irino, T.; Pedersen, T. F.
  Proceedings of the Ocean Drilling Program: Scientific Results, 167, 2000, [Peer-reviewed]
  Scientific journal
• Land-ocean linkages over orbital and millennial timescales recorded in late Quaternary sediments of the Japan Sea
  Tada, R.; Irino, T.; Koizumi, I.
  Paleoceanography, 14, 2, 1999, [Peer-reviewed]
  Scientific journal
• 287 Paleo-environmental changes at ODP Site 1017, off California during the last 50,000 years.
  Sato S.; Tada R.; Irino T.; Takayama H.; Leg167 Shipboard Scientific Party
  Annual Meeting of the Geological Society of Japan, 1997, 245, 245, The Geological Society of Japan, 1997
  Japanese
• 225. Palaeoclimat ological significance of the Dans gaard Oscillation signal recorded in the Quat emary sediments of the Japan Sea
  TADA Ryuji; IRINO Tomohisa; KOIZUMI Itaru
  Annual Meeting of the Geological Society of Japan, 1995, 199, 199, The Geological Society of Japan, 1995
  Japanese
• 233. The flux variation of Kosa and the Japan Arc derived detritus at ODP Sites 797 and 798 in the Japan Sea during the last 200 ky
  IRINO Tomohisa; TADA Ryuji
  Annual Meeting of the Geological Society of Japan, 1995, 203, 203, The Geological Society of Japan, 1995
  Japanese
• Reconstruction of Miocene volcanic seamount and the sedimentation depth for siliceous shale of the Onnagawa Formation in the Fujisato area,northern Akita
  Yamamoto Shinji; Irino Tomohisa; Tada Ryuji; Iijima Azuma
  Journal of the Geological Society of Japan, 100, 8, 557, 573, The Geological Society of Japan, 15 Aug. 1994, [Peer-reviewed]
  Japanese
• 158. The origin and flux varlation of the detritan components at ODP Sltes 797 and 798 in the Japan Sea during the late Quaternary
  IRINO Tomohisa; TADA Ryuji
  Annual Meeting of the Geological Society of Japan, 1994, 127, 127, The Geological Society of Japan, 1994
  Japanese
• 122 Depth of sedimentation for the Middle Miocene siliceous shale in the Fujisato area, Akita
  Yamamoto Shinji; Irino Tomohisa; Tada Ryuji; Iijima Azuma
  Annual Meeting of the Geological Society of Japan, 1990, 255, 255, The Geological Society of Japan, 1990
  Japanese

• Onset and evolution of millennial-scale variability of East Asian summer monsoon and its linkage with AMOC
  Tada Ryuji; Seki Arisa; Irino Tomohisa; Ikehara Ken; Itaki Takuya; Sagawa Takuya; Kubota Yoshimi; Sugisaki Saiko; Karasuda Akinori; Mitake Kaz; Ikeda Masayuki; Murayama Masafumi; Murray Richard W.; Zarikian Carlos A.; Scientist Expedition 346, Annual Meeting of the Geological Society of Japan, 2019, 0, 153, 153, 2019
  

  , The Geological Society of Japan, Japanese
• Close connection between East Asian monsoon and AMOC during the last 2.72 Ma
  Tada Ryuji; Ikeda Masayuki; murayama Masafumi; Murray Richard W; Alvarez-Zarikian Carlos A; Expedition 346 Scientists; Seki Arisa; Irino Tomohisa; Ikehara Ken; Itaki Takuya; Sagawa Takuya; Kubota Yoshimi; Sugisaki Saiko; Karasuda Akinori, Annual Meeting of the Geological Society of Japan, 2018, 0, 178, 178, 2018
  [Program canceled for a disaster] Program canceled for the 2018 Hokkaido Eastern Iburi earthquake. However, This abstract is quotable and viewable on PDF., The Geological Society of Japan, Japanese
• Onset and evolution of centennial to millennial-scale variations of East Asian Summer Monsoon and their significance in global climatic changes
  Tada Ryuji; Lu Song; Seki Arisa; Kurokawa Shunsuke; Mitake Kaz; Murayama Masafumi; Irino Tomohisa; Karasuda Akinori; Ikehara Ken; Sagawa Takuya; Itaki Takuya; Sugisaki Saiko; Kubota Yoshimi; Ikeda Masayuki, Annual Meeting of the Geological Society of Japan, 2017, 0, 163, 163, 2017
  [Program canceled for typhoon] Program canceled for typhoon. However, This abstract is quotable and viewable on PDF., The Geological Society of Japan, Japanese
• 大雪山地域の高層湿原泥炭の鉱物組成に基づく完新世における黄砂供給量の変動
  入野智久; 平井啓介; 関宰; HOOPER James; MARX Samuel K, 日本地球惑星科学連合大会予稿集(Web), 2017, ROMBUNNO.MIS23‐P13 (WEB ONLY), 2017
  Japanese
• Controlling mechanism for mineral composition of suspended materials during a flood event at the Saru River, Hokkaido
  Irino Tomohisa; Nakata Satoshi; Ikehara Ken; Yamashita Youhei; Seki Osamu; Nagao Seiya, Annual Meeting of the Geological Society of Japan, 2017, 0, 062, 2017
  The Geological Society of Japan, Japanese
• 三陸沖におけるイベント堆積物の保存可能性
  新井和乃; 小栗一将; 笠谷貴史; 野牧秀隆; 入野智久; 池原研; 齋藤有, ブルーアース要旨集, 2016, 2016
• 日本海若狭湾沖における採泥結果~KR15‐10航海の概要報告~
  佐川拓也; 池原研; 中川毅; 入野智久; 高橋聡; 久保田好美; 松崎賢治; 鈴木克明; 小坂由紀子; LU Song; 多田賢弘; HOLBORNE Ann; HENDERSON Andrew; HUANG Huai‐Hsuan, ブルーアース要旨集, 2016, 42, 2016
  Japanese
• 津波起源混濁流の発生可能性:2011年東北沖地震からの示唆
  新井和乃; 成瀬元; 横川美和; 入野智久; 池原研; 齋藤有; 林田明; 金松敏也, 日本地球惑星科学連合大会予稿集(Web), 2015, 2015
• Classification of dark and light layers in Quaternary sediments of the Japan Sea based on color and its application to identification of glacial- interglacial cycles
  Seki Arisa; Tada Ryuji; Irino Tomohisa; Karasuda Akinori; Murray Richard W.; Alvarez Zarikian Carlos; Expedition 346 Scientists, Annual Meeting of the Geological Society of Japan, 2015, 596, 2015
  The Geological Society of Japan
• ターミナル海盆における2004年紀伊半島南東沖地震の地震性堆積物
  芦寿一郎; 大村亜希子; 奥津なつみ; 山口飛鳥; 入野智久; 村山雅史; 池原研; 中村恭之, 日本地球惑星科学連合大会予稿集(Web), 2015, ROMBUNNO.SCG64‐P11 (WEB ONLY), 2015
  Japanese
• 終端堆積盆に記録された2004年紀伊半島南東沖地震時の地震性堆積物
  芦寿一郎; 大村亜希子; 山口飛鳥; 中村祐貴; 福地里菜; 入野智久; 村山雅史; 池原研; 中村恭之, 日本地質学会学術大会講演要旨, 121st, 86, 10 Sep. 2014
  Japanese
• Temporal variation of very fine elemental carbon in sediments from the Lake Kushu in the Rebun Island during the last 3000 years
  Irino Tomohisa; Nakai Yoshie; Yamamoto Masanobu; Miyazaki Yuzo; Kawamura Kimitaka; Yamada Kazuyoshi; Yonenobu Hitoshi, Abstracts of Annual Meeting of the Geochemical Society of Japan, 61, 0, 287, 287, 2014
  遠距離輸送されるバイオマス燃焼起源物質の定量を目指して，堆積物中の極細粒元素状炭素（EC）量評価のために，Thermal optical transmittance法の応用を検討した．スクロース，フミン酸，フルボ酸，フラーレンのEC・有機炭素（OC）分析を行った結果，O2雰囲気，550℃-700℃に耐えるOCも存在することが分かったので，700℃-850℃で検出されるフラクションのみをECとして定義した．この方法で，礼文島・久種湖の湖底堆積物コアから選んだ試料を，2μmを境に粗粒および細粒に分画し，それぞれの粒度画分についてEC・OC分析を行った．その結果，粗粒・細粒画分中のEC・OC変動が異なる事が分かり、粗粒ECはローカルな，細粒ECはローカル，遠方両方のバイオマス燃焼起源である可能性が示唆された．ECの細粒/粗粒比変動は大陸規模でのバイオマス燃焼変動を反映する可能性がある．, GEOCHEMICAL SOCIETY OF JAPAN, Japanese
• 東北沖浅海域における東北地方太平洋沖地震・津波に伴うイベント堆積物
  新井和乃; 成瀬元; 入野智久; 池原研; 笠谷貴史; 金松敏也; 野牧秀隆; 齋藤有; 横川美和; 泉典洋, ブルーアース要旨集, 2013, 2013
• 471 Late Holocene human impact on vegetation changes around Beppu Bay in northeast Kyushu, southwest Japan based on the influx pollen data dated by a wiggle-matching
  Shimada Misaki; Takahara Hikaru; Kuwae Michinobu; Yamamoto Masanobu; Ikehara Ken; Irino Tomohisa; Takemura Keiji; Sagawa Takuya; Sakamoto Tatsuhiko; Ikehara Minoru; Takeoka Hidetaka, 日本花粉学会会誌, 58, 212, 213, 23 Aug. 2012
  Palynological Society of Japan, English
• 178 Detection and characterisation of millennial-scale vegetation and climate variability in Quaternary pollen records from East Asia -recent progress and future perspective
  Hayashi Ryoma; Takahara Hikaru; Igarashi Yaeko; Kumon Fujio; Liew Ping-Mei; Yamamoto Masanobu; Kawai Sayuri; Oba Tadamichi; Irino Tomohisa; Shichi Koji, 日本花粉学会会誌, 58, 81, 82, 23 Aug. 2012
  Palynological Society of Japan, English
• 東シナ海における古細菌および真正細菌群集の検出と鉛直分布
  片岡剛文; 入野智久; 山本正伸; 鈴木光次; 東正剛, 日本海洋学会大会講演要旨集, 2009, 185, 23 Mar. 2009
  Japanese
• O-193 Changes in sea surface temperature in Okinawa Islands during the last 3,000 years
  Kitamura Akihisa; Yamamoto Nagisa; Irino Tomohisa; Kase Tomoki, 日本地質学会学術大会講演要旨, 114, 157, 157, 01 Sep. 2007
  The Geological Society of Japan, Japanese
• S-60 Holocene 1500-year variation of the Kuroshio Current
  Yamamoto Masanobu; Isono Dai; Irino Tomohisa; Murayama Masafumi; Nakamura Toshio; Kawahata Hodaka, Annual Meeting of the Geological Society of Japan, 2006, 0, 31, 31, 2006
  The Geological Society of Japan, Japanese
• 「みらい」MR02-K03 PC-2の珪藻化石群集に基づく過去20万年間の黒潮系暖水の変遷
  小泉 格; 入野 智久; 三島 稔明, 海洋科学技術センタ-試験研究報告, 48, 1, 9, Dec. 2003
  海洋科学技術センタ-, Japanese
• 「みらい」のMR01-K02 PC-1中の珪藻化石群集に基づく最終氷期末期--現間氷期における黒潮系暖水の変遷
  小泉 格; 入野 智久; 山本 浩文, 海洋科学技術センタ-試験研究報告, 46, 39, 46, Nov. 2002
  海洋科学技術センタ-, Japanese
• 北西太平洋域における完新世および最終氷期の風成塵フラックスと粒度 (総特集 海洋生物生産の加速と海洋大気)
  入野 智久, 海洋, 34, 3, 156, 161, Mar. 2002
  海洋出版, Japanese
• 「みらい」MR00-K05 PC-1及びPC-2の珪藻化石群集に基づく最終氷期末期〜現間氷期における黒潮系暖水の変遷
  小泉 格; 入野 智久; 山本 浩文, 海洋科学技術センタ-試験研究報告, 44, 29, 40, Nov. 2001
  海洋科学技術センタ-, Japanese
• 159. Establishment of the methods for the extraction of detrital components from diatomaceous sediments and the detrital grain size analysis
  Irino Tomohisa, 日本地質学会学術大会講演要旨, 100, 377, 377, 25 Mar. 1993
  The Geological Society of Japan, Japanese

• 海洋底科学の基礎
  日本地質学会「海洋底科学の基礎」編集委員会
  共立出版, Sep. 2016, 9784320047297, ix, 389p, 図版 [8] p, Japanese, [Contributor]
• 地球と宇宙の化学事典
  日本地球化学会
  朝倉書店, Sep. 2012, 9784254160574, xvi, 479p, 図版 [8] p, Japanese, [Contributor]
• 地球温暖化の科学
  北海道大学出版会, 2007, [Contributor]

• Onset and evolution of millennial-scale variability of East Asian summer monsoon and its linkage with AMOC
  Tada Ryuji; Mitake Kaz; Ikeda Masayuki; Murayama Masafumi; Murray Richard W.; Zarikian Carlos A.; Scientist Expedition 346; Seki Arisa; Irino Tomohisa; Ikehara Ken; Itaki Takuya; Sagawa Takuya; Kubota Yoshimi; Sugisaki Saiko; Karasuda Akinori
  Annual Meeting of the Geological Society of Japan, 2019, The Geological Society of Japan, Japanese
  2019 - 2019,

• Progress report of the project to specify the location and magnitude of the Australasian tektite impact event
  Tada Ryuji; Okada Makoto; Suganuma Yusuke; Irino Tomohisa; Kubota Yoshimi; Tada Toshihiro; Carling Paul; Songtham Wichanet; Le Xuen Thuyen; Kayama Masahiro; Chang Yu; Kurosawa Kosuke; Tajika Eiichi
  Annual Meeting of the Geological Society of Japan, 2019, The Geological Society of Japan, Japanese
  2019 - 2019,

• Close connection between East Asian monsoon and AMOC during the last 2.72 Ma
  Tada Ryuji; Ikeda Masayuki; murayama Masafumi; Murray Richard W; Alvarez-Zarikian Carlos A; Expedition 346 Scientists; Seki Arisa; Irino Tomohisa; Ikehara Ken; Itaki Takuya; Sagawa Takuya; Kubota Yoshimi; Sugisaki Saiko; Karasuda Akinori
  Annual Meeting of the Geological Society of Japan, 2018, The Geological Society of Japan, Japanese
  2018 - 2018, [Program canceled for a disaster] Program canceled for the 2018 Hokkaido Eastern Iburi earthquake. However, This abstract is quotable and viewable on PDF.
• Controlling mechanism for mineral composition of suspended materials during a flood event at the Saru River, Hokkaido
  Irino Tomohisa; Nakata Satoshi; Ikehara Ken; Yamashita Youhei; Seki Osamu; Nagao Seiya
  Annual Meeting of the Geological Society of Japan, 2017, The Geological Society of Japan, Japanese
  2017 - 2017
• 大雪山地域の高層湿原泥炭の鉱物組成に基づく完新世における黄砂供給量の変動
  入野智久; 平井啓介; 関宰; HOOPER James; MARX Samuel K
  日本地球惑星科学連合大会予稿集(Web), 2017, Japanese
  2017 - 2017
• Onset and evolution of centennial to millennial-scale variations of East Asian Summer Monsoon and their significance in global climatic changes
  Tada Ryuji; Lu Song; Seki Arisa; Kurokawa Shunsuke; Mitake Kaz; Murayama Masafumi; Irino Tomohisa; Karasuda Akinori; Ikehara Ken; Sagawa Takuya; Itaki Takuya; Sugisaki Saiko; Kubota Yoshimi; Ikeda Masayuki
  Annual Meeting of the Geological Society of Japan, 2017, The Geological Society of Japan, Japanese
  2017 - 2017, [Program canceled for typhoon] Program canceled for typhoon. However, This abstract is quotable and viewable on PDF.
• 日本海若狭湾沖における採泥結果~KR15‐10航海の概要報告~
  佐川拓也; 池原研; 中川毅; 入野智久; 高橋聡; 久保田好美; 松崎賢治; 鈴木克明; 小坂由紀子; LU Song; 多田賢弘; HOLBORNE Ann; HENDERSON Andrew; HUANG Huai‐Hsuan
  ブルーアース要旨集, 2016, Japanese
  2016 - 2016
• ターミナル海盆における2004年紀伊半島南東沖地震の地震性堆積物
  芦寿一郎; 大村亜希子; 奥津なつみ; 山口飛鳥; 入野智久; 村山雅史; 池原研; 中村恭之
  日本地球惑星科学連合大会予稿集(Web), 2015, Japanese
  2015 - 2015
• 終端堆積盆に記録された2004年紀伊半島南東沖地震時の地震性堆積物
  芦寿一郎; 大村亜希子; 山口飛鳥; 中村祐貴; 福地里菜; 入野智久; 村山雅史; 池原研; 中村恭之
  日本地質学会学術大会講演要旨, 10 Sep. 2014, Japanese
  10 Sep. 2014 - 10 Sep. 2014
• Temporal variation of very fine elemental carbon in sediments from the Lake Kushu in the Rebun Island during the last 3000 years
  Irino Tomohisa; Nakai Yoshie; Yamamoto Masanobu; Miyazaki Yuzo; Kawamura Kimitaka; Yamada Kazuyoshi; Yonenobu Hitoshi
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 2014, GEOCHEMICAL SOCIETY OF JAPAN, Japanese
  2014 - 2014, 遠距離輸送されるバイオマス燃焼起源物質の定量を目指して，堆積物中の極細粒元素状炭素（EC）量評価のために，Thermal optical transmittance法の応用を検討した．スクロース，フミン酸，フルボ酸，フラーレンのEC・有機炭素（OC）分析を行った結果，O2雰囲気，550℃-700℃に耐えるOCも存在することが分かったので，700℃-850℃で検出されるフラクションのみをECとして定義した．この方法で，礼文島・久種湖の湖底堆積物コアから選んだ試料を，2μmを境に粗粒および細粒に分画し，それぞれの粒度画分についてEC・OC分析を行った．その結果，粗粒・細粒画分中のEC・OC変動が異なる事が分かり、粗粒ECはローカルな，細粒ECはローカル，遠方両方のバイオマス燃焼起源である可能性が示唆された．ECの細粒/粗粒比変動は大陸規模でのバイオマス燃焼変動を反映する可能性がある．
• 東シナ海における古細菌および真正細菌群集の検出と鉛直分布
  片岡剛文; 入野智久; 山本正伸; 鈴木光次; 東正剛
  日本海洋学会大会講演要旨集, 23 Mar. 2009, Japanese
  23 Mar. 2009 - 23 Mar. 2009
• S-60 Holocene 1500-year variation of the Kuroshio Current
  Yamamoto Masanobu; Isono Dai; Irino Tomohisa; Murayama Masafumi; Nakamura Toshio; Kawahata Hodaka
  Annual Meeting of the Geological Society of Japan, 2006, The Geological Society of Japan, Japanese
  2006 - 2006

• 古海洋学特論, 2024年, 修士課程, 環境科学
• 大学院共通授業科目（一般科目）：自然科学・応用科学, 2024年, 修士課程, 大学院共通科目
• 古環境学基礎論, 2024年, 修士課程, 環境科学
• 古環境学基礎論, 2024年, 修士課程, 環境科学院
• 海洋地質学, 2024年, 学士課程, 理学部
• 地球惑星科学実験Ⅱ, 2024年, 学士課程, 理学部
• 堆積学, 2024年, 学士課程, 理学部
• 一般教育演習(ﾌﾚｯｼｭﾏﾝｾﾐﾅｰ), 2024年, 学士課程, 全学教育

• Paleosciences Society
• Geological Society of Japan
• Geochemical Society of Japan
• Japan Association for Quaternary Research
• Sedimentological Society of Japan
• SEPM (Society for Sedimentary Geology)
• American Geophysical Union

• 陸域で生成される超難分解な燃焼起源有機物の海洋への移行および埋没過程の定量評価
  科学研究費助成事業
  01 Apr. 2025 - 31 Mar. 2029
  山下 洋平; 宮崎 雄三; 入野 智久; 野牧 秀隆
  日本学術振興会, 基盤研究(A), 北海道大学, 25H01176
• Reconstruction of atmospheric carbon dioxide conentrationover the past ten million years
  Grants-in-Aid for Scientific Research
  01 Apr. 2024 - 31 Mar. 2028
  山本 正伸; 吉森 正和; 阿部 彩子; 関 宰; 入野 智久; 岩崎 晋弥
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 24H00256
• 海洋に存在する熱成有機物のミッシングソースの解明
  科学研究費助成事業
  01 Apr. 2022 - 31 Mar. 2026
  山下 洋平; 宮崎 雄三; 入野 智久
  バイオマスや化石燃料の燃焼などで生じる熱成有機物の大部分は、生物学的反応性に乏しい超難分解性成分であり、地球表層炭素循環から二酸化炭素を隔離する役割を有する。しかし、熱成有機物の末路に関する知見は乏しく、熱成有機物は炭素循環の収支に考慮されていない。これまでの研究により、海洋の溶存有機物画分中に熱成有機物が普遍的に存在すること、その溶存熱成有機物は沈降粒子に吸着し海底へと除去されることが示された。また、溶存熱成有機物の海底への除去フラックスから、海洋には溶存熱成有機物の未知の供給源 (ミッシングソース) が存在することが示された。本研究では、海洋に存在する溶存熱成有機物のミッシングソースとして深海熱水噴出孔および大気沈着に着目し、これらが海洋の溶存熱成有機物の分布やそのプールの動態に与える影響を定量的に解明することを目指す。
  深海熱水噴出孔に関しては、北太平洋および南太平洋の東太平洋海膨付近をカバーする海域における溶存熱成有機物の東西および南北断面分布を明らかにし、それらと溶存酸素濃度やヘリウム同位体比の断面分布を比較した。その結果、東太平洋海膨の熱水活動に由来する溶存熱成有機物の濃度を定量化することに成功し、深海熱水由来の溶存熱成有機物の全球フラックスを見積もることができた。また、2022年12月に明神海丘の熱水域において溶存および粒子状の熱成有機物の試料を採取することに成功した。
  大気沈着に関しては、北海道大学大学院地球環境科学研究院の屋上にて、2023年8月から大気エアロゾル試料の採取を開始した。予備的な実験および解析を行った結果、大気エアロゾル中の溶存熱成有機物は黒色炭素濃度および水溶性有機炭素濃度と関係することが明らかとなった。
  日本学術振興会, 基盤研究(B), 北海道大学, 23K24969
• 霞ヶ浦における過去5000年間の季節を分けた洪水史復元
  科学研究費助成事業
  01 Apr. 2022 - 31 Mar. 2026
  山田 桂; 香月 興太; 多田 隆治; 鈴木 健太; 入野 智久; 多田 賢弘
  2023年5月から6月にかけて，霞ヶ浦（西浦）の南東（KS23-01）と北西（KS23-02）の2地点において，パーカッションピストンコアラーを用いて，長さ4 mを超えるコア試料を採取した．また，各地点ではリムノスコアラーであらかじめ表層堆積物を乱さずに採取した．いずれのコアも長さ約1 mに切断した後，縦に半割し，それぞれ記載と写真撮影をおこなった．
  半割した片方の試料はCTスキャン，磁化率の測定，元素濃度測定用にスラブ試料を切り取り，残りは厚さ2 cm間隔で分割した．もう片方は厚さ1 cmより細かな検討を行うためと珪藻分析用に，Lチャンネルを用いて試料を採取した．その残りは，有機物分析用を分取した後，貝形虫および粒度分析用試料とし，厚さ1 cmにカットして保存した．
  高知大学海洋コア国際研究所の機器を借用し，KS22-03，KS22-04，KS23-01, KS23-02コアから得たスラブ試料について，CTスキャンによる堆積構造の観察，マルチセンサーロガーによる磁化率の測定をおこなった．その結果，各試料の堆積構造やその変化を把握することができた．また，KS23-02コアについては複数枚のテフラ層が存在することがわかった．
  KS23-02試料は顕微鏡下での堆積物の観察を行い，浅間Aなど湖内で追跡できるテフラ層を確認し，堆積速度を見積もった．また，KS23-01とKS23-02の試料から得られた二枚貝殻2試料を外部に委託し，14C年代測定を実施した．これらの結果に加え，分析を実施した二枚貝の14C年代測定の結果と合わせて，KS22-04及びKS23-01コアは過去6000年間を，KS23-02は過去3000年間の堆積物を保存していることが明らかになった．さらにKS22-04, 23-01及び23-02コアの全ての試料について，粒度分析を行い，その変化から古環境変遷を検討した．
  日本学術振興会, 基盤研究(B), 信州大学, 23K22578
• Elucidation of variation in marine primary production and biogeochemical linkages between land and ocean in North Pacific Ocean during the Neogene
  Grants-in-Aid for Scientific Research
  01 Apr. 2022 - 31 Mar. 2026
  沢田 健; 桑田 晃; 力石 嘉人; 入野 智久; 加藤 悠爾
  本研究では、深海掘削および陸上調査によって得られた新第三紀堆積物から、藻類および陸上植物の分子化石（バイオマーカー）、藻類微化石、生物源シリカを分析し、新生代の北太平洋におけるグローバルな海洋ー陸域間の生物地球化学的循環と生態系の連鎖（リンケージ）、環境気候システムとの関連性を解明する。海洋・陸域生態系が駆動する長時間スケールの物質循環システムの解明という観点から、海洋基礎生産と陸源有機物の海洋への輸送量の変動の体系的で定量性の高い復元を目指す。さらに、新しい古環境復元法を確立するため、新規の藻類バイオマーカーの探索とその解析法、陸上植物バイオマーカーの分子内同位体比解析法を開発する。2022年度における主な研究成果は次のとおりである。
  1. 北部北太平洋アラスカ湾掘削コア（U1417）のバイオマーカー分析を行い、珪藻、ハプト藻、渦鞭毛藻、真正眼点藻などに由来するバイオマーカーを検出し、低分解能で大まかではあるが過去1000万年間の海洋基礎生産変動を復元した。また、ハプト藻由来の長鎖アルケノンおよび真正眼点藻由来の長鎖アルキルジオールを用いた古水温計によって海洋表層水温の変動を復元した。これらの水温の変動パターンは概ねよく一致し、全体的には中新世以降の全球的な寒冷化傾向を示すことがわかった。
  2. 北海道中南部の日高町などに分布する中新統荷菜層における泥質堆積岩から、陸上セクションからは極稀な長鎖アルケノンが検出されることを発見した。そのアルケノン古水温計を用いて中期～後期中新世における体系的な海洋表層水温と海洋基礎生産の変動を復元した。
  3. 陸源有機物において陸上植物だけでなく菌類のような生物のバイオマーカーにも着目し、特に地衣類の生体試料を用いて、新規のバイオマーカーを検討した。その結果、ファルネンなどのテルペノイドがそのバイオマーカーになり得ることを明らかにした。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 23K22610
• 海洋に存在する熱成有機物のミッシングソースの解明
  科学研究費助成事業
  01 Apr. 2022 - 31 Mar. 2026
  山下 洋平; 宮崎 雄三; 入野 智久
  日本学術振興会, 基盤研究(B), 北海道大学, 22H03714
• Elucidation of the variation in marine primary production and the land-ocean biogeochemical linkage in North Pacific Ocean
  Grants-in-Aid for Scientific Research
  01 Apr. 2022 - 31 Mar. 2026
  沢田 健; 桑田 晃; 力石 嘉人; 入野 智久; 加藤 悠爾
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 22H01339
• 霞ヶ浦における過去5000年間の季節を分けた洪水史復元
  科学研究費助成事業
  01 Apr. 2022 - 31 Mar. 2026
  山田 桂; 香月 興太; 多田 隆治; 入野 智久; 多田 賢弘; 鈴木 健太
  日本学術振興会, 基盤研究(B), 信州大学, 22H01307
• Reconstruction of atmospheric carbon dioxide concentration during the last 6 million years and the study of the interaction between atmospheric carbon dioxide and climate
  Grants-in-Aid for Scientific Research
  26 Jun. 2019 - 31 Mar. 2024
  山本 正伸; 吉森 正和; 阿部 彩子; 関 宰; 入野 智久
  温室効果は地球表層の温度を決める重要な要素である。大気中CO2濃度の連続的な測定は1957年以降であり、それ以前のCO2濃度はアイスコア気泡中のガス測定により復元されている（Luthi et al., 2008など）。しかし、アイスコアの最古の氷は80万年前のものであり、それ以前のCO2濃度の精密復元は行われていない。
  本研究では、ベンガル湾の国際深海掘削科学計画（IODP）U1445地点の堆積物コアに含まれる長鎖脂肪酸の安定炭素同位体比（δ13CFA）を測定し、600万年前以降のCO2濃度を約1700年解像度で復元する。得られたデータにもとづき、鮮新世における気候感度を推定し、温暖期におけるCO2濃度と全球気温の関係を検討する。さらに、過去600万年間のCO2濃度と海洋深層水温度・気温・氷床量変動との関係から、CO2濃度変動の原因を考察し、CO2と気候の相互作用を解明する。
  脂肪酸同位体比測定は全3200試料が終了した。過去80万年間のCO2濃度復元値は、アイスコアのCO2濃度およびU1446地点でのCO2濃度復元値と良い一致を示し、当研究で用いているCO2濃度復元手法をU1445地点に適用することが妥当であることが確かめられた。国際深海掘削科学計画（IODP）U1445地点での船上分析により得られた生層序と非破壊分析の結果に基づき仮の年代モデルを作成した。
  U1446地点で得られたCO2濃度変動記録と過去150万年間の降水量変動を比較し、δ13CFA変動の2-10%は降水量変動により、 78%がCO2濃度変動でより説明可能であることを示した。CO2濃度と降水量の変動がインド東部のC3/C4植生に与える影響を植生モデルを用いて検討した。このモデルの結果からも、δ13CFA変動は基本的にCO2変動を反映していることが明らかになった。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (S), Hokkaido University, 19H05595
• Refinement of biomarker-based paleovegetation analysis, and its application to reconstruction of the paleovegetational variation in the northern Japan over the past 5 million years
  Grants-in-Aid for Scientific Research
  01 Apr. 2018 - 31 Mar. 2021
  Sawada Ken
  The objective of this study is to reconstruct variations in paleovegetation and terrestrial paleoenvironment by analyses of terrestrial plant-derived biomarkers and pollen/spore in sediment cores from Japan Sea off Hokkaido (U1422 and U1423 cores) collected by the International Ocean Drilling Program (IODP). We reconstructed the paleovegetation variations during ca. 4.3 million years and centurial-scale variations during ca. 700 kiloyears in U1423 and U1422 sites, respectively. The paleovegetation variations reconstructed by the coniferous diterpenoids and the triterpenoids derived by broad-leaved tree are synchronous to the global climatic variations such as warm/cool conditions with glacial/interglacial or centurial scales, elucidating paleoclimatic system variations related to monsoonal system in the northern Japan Sea by combined analyses of organic molecules and pollens.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 18H01322
• Reconstruction of the Pacific Decadal Oscillation during the last 8000 years by the analysis of Beppu Bay sediment cores
  Grants-in-Aid for Scientific Research
  01 Apr. 2016 - 31 Mar. 2019
  Yamamoto Masanobu
  We analyzed paleotemperature and fish scale abundance in sediments from two 20 m-long cores retrived from Beppu Bay, Kushu, Japan and generated a four-year resolution records of the Pacific Decadal Oscillation and regime shifts during the last 8000 years. The result indicates that the periods of dominant 50-year and 200-year cycles were exchanged on muti-centennial scale, suggesting a modulation of the Pacific Decadal Oscillation by external forcing, most likely, both solar and volcanic forcings.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 16H02232
• Centennial to millennial-scale variability of East Asian Monsoon: Onset timing, temporal changes, and their controlling factors
  Grants-in-Aid for Scientific Research
  01 Apr. 2016 - 31 Mar. 2019
  Tada Ryuji; SEKI Arisa; WANG Ke; MITAKE Kaz; MATSUZAKI Kenji; KUROKAWA Shunsuke
  Variations of Marine Organic Carbon (MOC) content in the dark and light hemipelagic sediments from the deeper part of the Japan Sea reflect variability of East Asian Summer Monsoon (EASM) precipitation through nutrient influx through the Tsushima Strait and consequent enhancement of surface productivity in the sea. We used IODP cores from 3 depth transect sites in the Japan Sea and reconstructed temporal changes in EASM intensity during the last 3 Ma based on high-resolution analyses of the cores. The result revealed onset of millennial-scale large and abrupt changes of EASM intensity at 1.31 Ma, temporal changes in their periodicity and amplitude was closely related with the ice volume and its growth rate, and changes in westerly jet path seem to play a critical role in propagation of the signal from high-latitude North Atlantic.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), The University of Tokyo, 16H01765
• Accuracy improvement of earthquake history of the Nankai Trough by sediment records from terminal basins
  Grants-in-Aid for Scientific Research
  01 Apr. 2015 - 31 Mar. 2018
  Ashi Juichiro; IRINO Tomohisa; YAMAGUCHI Asuka; OMURA Akiko
  We conducted shallow subbottom profiling survey and sediment core sampling in the Nankai forearc region to know the earthquake history from off Tokai to off Hyuga. A subbottom profiler on a remotely operated vehicle successfully obtained high-resolution shallow subseafloor structures from the trench landward slope to the forearc basin, and found active faults and on-going tilting off Cape Muroto and off Hyuga. Sedimentological study revealed rework and redeposition processes of surface sediments by earthquake shaking and suggested that the thickness of the redeposited layer could correlate with the depth of the reworked unit of the source formation.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), The University of Tokyo, 15H02988
• Reconstruction of variations in paleovegetation during the Quaternary by analysis of plant-derived organic molecule in the deep sea drilling sediment cores from the Atlantic Ocean and Japan Sea
  Grants-in-Aid for Scientific Research
  01 Apr. 2014 - 31 Mar. 2017
  Sawada Ken; IGARASHI Yaeko
  The objective of this study is to reconstruct variations in paleovegetation and terrestrial paleoenvironment by analyses of terrestrial plant-derived biomarkers and pollen/spore in sediment cores from northeastern Atlantic Ocean off the Iberian Peninsula (U1385) and the Japan Sea off the southwestern coast of Hokkaido (U1423) collected by the International Ocean Drilling Program (IODP). We reconstructed the paleovegetation variations during 4.3 million years and centurial-scale variations during the marine isotope stages (MIS) 12 - 10 in U1423 and U1385 sites, respectively. In particular, the paleovegetation variations reconstructed by the indicators for diterpenoids derived from Taxodiaceae/Cupressaceae and Pinaceae are synchronous to the global climatic variations such as warm/cool conditions with glacial/interglacial or centurial scales, confirming high applicability of the terpenoid proxy for reconstructing paleovegetation from deep sea sediment.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 26287130
• Understanding the mechanisms controlling the environmental dynamics of radionuclides released from the Fukushima Daiichi Nuclear Power Plant in the ocean.
  Grants-in-Aid for Scientific Research
  28 Jun. 2012 - 31 Mar. 2017
  YAMADA MASATOSHI; UEMATSU Mitsuo; KAWAKAMI Hajime; IKEHARA Ken; IRINO Tomohisa; TAKAHATA Naoto; MASUMOTO Norio; ISOBE Atsuhiko; KIDA Shinichiro; TSUBONO Takaki; MISUMI Kazuhiro; INOMATA Yayoi; KAERIYAMA Hideki; KUSAKABE Masashi; YANG Guosheng; NAKANO Toshiya; POVINEC Pavel; BUESSELER Ken; HULT Mikael; NIES Hartmut
  The Fukushima Dai-ichi Nuclear Power Plant(FNPP1) accident has resulted in a substantial release of radionuclides to the atmosphere and ocean, and has caused extensive contamination of the environment. The objectives of this study were to collect seawaters, marine sediments and settling particles in Japanese coast and North Pacific Ocean and to understand the condition and factor of the radionuclide distribution therein. FNPP1-derived radiocesium spread eastward in the surface water across the mid-latitude North Pacific with a speed of 7 km/day and it had been transported into the ocean interior due to formation/subduction of subtropical mode water and central mode water. The release of Pu isotopes from the FNPP1 accident to the marine environment was negligible. The FNPP1-derived radiocesium was detected in settling particles collected at 4810 m in early April 2011 at station in the subarctic gyre and it was quickly transported to the deep sea in the western North Pacific.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Hirosaki University, 24110004
• High resolution reconstruction of Holocene sea surface temperature in the Southern Ocean and the Arctic Ocean
  Grants-in-Aid for Scientific Research
  01 Apr. 2013 - 31 Mar. 2016
  Yamamoto Masanobu; IRINO Tomohisa; YOKOYAMA Yusuke
  TEX86 analysis indicated that sea surface temperature (SST) decreased from 12,000 years ago to 3,000 years ago and increased afterward off Wilkes Land in the Southern Ocean. In the Chukchi Sea of the Arctic, SST increased since 9,000 years ago. Both areas showed significant millennial-scale SST variability. In the Chukchi Sea core, the chlorite/illite ratio showed higher values in the middle Holocene, suggesting the intensified Bering Strait inflow. The Quartz/feldspar ratios showed a decreasing trend, suggesting a decline of the Beaufort Gyre circulation since 9,000 years ago.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 25287136
• Changes in hydrological cycle in East Asia during the Holocene and their implication for Global Monsoon
  Grants-in-Aid for Scientific Research
  01 Apr. 2011 - 31 Mar. 2016
  TADA Ryuji; NAKAGAWA Takeshi; ZHENG HONGBO
  Provenance changes of suspended sediments of the Yangtze River during the last 7 k.y. revealed millennial-scale changes in East Asian summer monsoon (EASM) precipitation front between NW and SE parts of the Yangtze drainage with SE-ward retreat during 5.4-3.5 and 1.9-0.2 k.y. These shifts are associated with southward shifts of the westerly jet(WJ) during the same periods deduced from provenance changes of eolian dust in the Japan Sea sediments, supporting the idea that northern limit of the EASM front is controlled by the position of the WJ. Floods record of Lake Suigetsu implies frequent storms during these periods suggesting shifts of the storm track. Comparison with Southern Hemisphere WJ position revealed symmetric movement of WJ in both hemispheres with respect to the equator, suggesting expansion and shrinkage of the Hadley circulations seem the cause of these changes. It is possible the solar activity is the ultimate forcing but further study is needed.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (S), The University of Tokyo, 23221002
• Development of new carbonate dissolution index by X-ray Tomography and geochemical proxies
  Grants-in-Aid for Scientific Research
  01 Apr. 2012 - 31 Mar. 2015
  KIMOTO Katsunori; SASAKI Osamu; IRINO Tomohisa; WAKITA Masahide
  We developed a novel method to know the shell density of calcareous zooplankton (foraminiera) by using Micro X-ray Computing Tomography (MXCT) successfully. We found that shell density of individual planktic foraminifers which were recovered by the sediment trap deployed at Stn. K2 (47N, 160E), North Pacific had remarkably changed seasonally. In particular, shell degradation progressed in winter season from December to April. According to observations of seawater chemistry, shell density changes might be closely associated with carbonate systems and related physicochemical parameters: vertical mixing, pH, TCO2 and Omega. Geochemical proxy (strontium-calcium ratio, Sr/Ca) of individual foraminiferal shell indicated strong correlation with shell density, and it suggests that Sr/Ca of foraminiferal shells has potential to be a quantitative tracer of carbonate dissolution. These result should contribute to understand material cycles of ocean and biogeochemical cycles.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Japan Agency for Marine-Earth Science and Technology, 24540505
• Analysis of ecosystem function of taiga in eastern Siberia
  Grants-in-Aid for Scientific Research
  2009 - 2012
  SUGIMOTO Atsuko; IRINO Tomohisa; OHOTE Nobuhito; TOKUCHI Naoko; IWAHANA Go; KODAMA Yuuji; YAMASHITA Yohei; ISHII Yoshiyuki; OHOTA Takeshi; UZUKI Rikie; YONENOBU Hitoshi
  Field observations were carried out on water, carbon, and nitrogen cycles in taiga and taiga-tundra boundary in eastern Siberia. Soil moisture water equivalent at taiga forest study site was reconstructed for pas 100 years from tree-ring 13C of larch. Our observational results showed that the wet condition in 2006-2007 was extreme event, and runoff from the region to Lena river was generated for a whole year during this period. N dynamics was also observed in larch forest. Soil inorganic N pool size showed large seasonality depending on the soil temperature.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 21403011
• Development of proxy for oceanic carbonate using Micro-X-ray CT technique
  Grants-in-Aid for Scientific Research
  2009 - 2011
  KIMOTO Katsunori; SASAKI Osamu; IRINO Tomohisa
  Quantitative evaluation methods of dissolution for marine carbonates(foraminifera) using Micro-focus X-ray Computing Tomography(MXCT) has developed. Quantity of carbonate dissolution is expressed by total CT value as shell volume, and mean CT value as shell density. Availability and usefulness of this method was confirmed for natural and laboratory samples.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Japan Agency for Marine-Earth Science and Technology, 21654073
• Reconstruction of changes in the atmospheric convection activity in the tropical Pacific Ocean during the last 150,000 years using hydrogen isotopes of biomarkers
  Grants-in-Aid for Scientific Research
  2007 - 2011
  YAMAMOTO Masanobu; IRINO Tomohisa; SUGIMOTO Atsuko; OKINO Tatsufumi
  We reconstructed the atmospheric convection activity in the tropical Pacific by analyzing biomarkers in marine cores retrieved from five locations in the tropical Pacific. Paleotemperature records demonstrated that the cold tongue shrunk, the western Pacific warm pool expanded, and zonal temperature gradient was relaxed during the last deglaciation. A deuterium record of fatty acids from the southern South China Sea disagrees with a published stalagmite record from northern Borneo. The latter is consistent with paleotemperature records, suggesting that zonal temperature gradient and the position of convection center has varied in response to precession.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 19204051
• 利尻島および日本海北部海域に降下するシベリア森林火災起源物質の時代変化
  2009
  Competitive research funding
• Temporal variation of charcoal deposition originated from Siberian forest fire in the Rishiri Island and the northern Japan Sea
  2009
  Competitive research funding
• Reconstruction of paleoceanographic variations of Kuroshio over the past 7,000 years from oxygen isotope ratio of the micro-bivalvia ound in a submarine cave
  Grants-in-Aid for Scientific Research
  2007 - 2008
  KITAMURA Akihisa; IRINO Tomohisa; KASE Tomoki
  海底洞窟から採取した堆積物コア試料に含まれる160個体の微小二枚貝の酸素同位体比を測定した. その結果, 現在よりもかなり寒冷・乾燥化した冬期が, 6,300年前, 5,550年前. 5,200年前に起きており, それらの期間は太陽活動の弱体期にあたる. このことから, 日本南方域の気候は, 太陽活動の影響を受けることが分かった.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Shizuoka University, 19540492
• Research of characteristics of riverine suspended particles released by heavy rain and their effects on coastal ecosystem
  Grants-in-Aid for Scientific Research
  2006 - 2008
  NAGAO Seiya; YAMAMOTO Masanobu; IRINO Tomohisa; HUJITAKE Nobuhide; ARAMAKI Takahumi
  石狩川河川水の懸濁態有機物の放射性炭素のδΔ14C値は年間を通じて大きな変動を示し、雪融けと降雨時には古い有機物が移動していることが明らかとなった。その変動幅は下流域<中流域<河口域<上流域の順であり、河川に供給される懸濁態の有機物は、河川流域環境や水の供給経路等の特徴と関連して変動することが考えられる。これらの結果から、沿岸域への影響評価には、雪融けと降雨時の粒子の供給量と供給機構の重要性が示唆された。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), 18310002
• The 2003 Hokkaido Hidaka flood : sedimentary processes in the open ocean and influence to sea bottom environments
  Grants-in-Aid for Scientific Research
  2005 - 2007
  IKEHARA Ken; KATAYAMA Hajime; NODA Atsushi; TUZINO Taqumi; IRINO Tomohisa; OMURA Akiko
  Floods supply large amounts of terrigenous materials to marine environments that affects sea bottom environments and strata formation. Quick deposition of large amount of sediments on sea floor may influence to sea floor environments. Because of few marine geological and sedimentological surveys have been conducted immediately after floods, behavior of flood sediments in marine environments and sedimentary processes are not well understood. In August 2003, heavy rain associated with by the typhoon 200310 caused flooding and landslides in Hidaka area, Hokkaido large amount of sand and mud were transported by rivers to ocean. Our survey indicated the two modes of flood mud deposition on the shelf. One is transportation by density (hyperpycnal) flows. Long distance transport across shelf was available by this mechanism. Another is diverse by hypopycnal surface plume. Flood mud was deposited near the river mouth by this system. Inner shelf submarine topography controls such a transportation mode. Taking into account of flood mud deposition on the outer shelf to deep-sea basin floor, the larger amount of terrigenous materials than those previously estimated from river observations were supplied to ocean by this flood. There results verify the importance of the hyperpycnal flow for long-distance transport of the terrigeouns materials to the deep-sea, and flood plays an important role on material supply to deep-sea.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), National Institute of Advanced Industrial Science and Technology, 17340151
• Evaluation of nutrient impact from river to coastal biogeochemical systems as an aspect from material transport processes
  Grants-in-Aid for Scientific Research
  2004 - 2007
  MINAGAWA Masao; NAGAO Seiya; IRINO Tomohisa; KATO Yoshisa; NARITA Hisashi; MURAYAMA Masafumi
  We have investigated biogeochemical role of river runoff at several locations in Hokkaido, Central Honshu and Shikoku districts and have evaluated the contribution of these river water for the coastal biological production that is dealing with the marine carbon cycling. Based on geochemical observations including nutrient and isotopic analyses at Tokachi river, Abe river, Niyodo river, and Shimanto river, we found following results. (1) Nutrient loadings from Tokachi river were estimated as 1.3 and 0.009 mol/m^2/yr for DIN, and DIP, respectively. (2) These nutrient discharge can have dealings with 8.4 molC/m^2/yr as photosynthesis and may benefit for diatom production by their N/P and Si/N ratios. (3) Sporadic events with heavy precipitation can supply large effect mainly for nitrogen which provides potentially corresponding to 8% DIN supply of mean annual transport flux. (4) River discharge in the snow melting season would supply 30 to 40% of nutrient needed for coastal biological production, on the other hand particulate organic carbon make for less than one tenth of carbon fixation and less than a half of PON nitrogen. (5) The first class rivers in Shizuoka prefecture tend to have relatively lower nitrogen content ranging from 27 to 98 μM, but those in the second class rivers showed higher concentrations ranging from 82 to 504 mM and even wide variations. The phosphate and silicate concentrations are ranging from 0.21 to 9.2 μM and from 109 to 413 μM, respectively, reflecting difference of local environmental conditions such as water shed area, land utilization pattern and degree of civilizations.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 16201001
• Improvement of paleo-SST and SSS reconstruction based on precise estimation of secondary calcification and dissolution of planktonic foraminifer test
  Grants-in-Aid for Scientific Research
  2005 - 2006
  IRINO Tomohisa
  Calcite test of planktonic foraminifer produced in surface ocean sinks in the water column after its death, deposits on the seafloor, and buried in the sediment. During these process, the weight of test decreases by dissolution and increases by secondary calcification. Weight loss of calcite test has been regarded as a good proxy for carbonate dissolution, however, estimation of secondary calcification is also necessary to know a true weight loss. Since secondary calcification occurs in the deep ocean, paleo-sea surface temperature (SST) and salinity (SSS) information recorded in isotope and chemical composition of test calcite would be also biased.
  In order to establish the method to estimate true weight loss from and addition on initial calcite test of planktonic foraminifer, weight and oxygen / carbon isotopes analyses were conducted on 50-70 individula foraminifer tests obtained from surface water, water column, and sediments in the western North Pacific. As a result of evaluation for Globigerinoides sacculifer tests,
  1) G. sac produce their tests in the surface water and attach gametogenic calcite in < 400 m water depth
  2) Gametogenic calcite increases test weight by~20%
  3) Dissolution slightly occur during sinking process but secondary calcification does not occur in the water column
  4) Significant dissolution occur on the sea floor followed by secondary calcification during burial process
  Positive correlation of oxygen isotope and weight suggests a strong influence of secondary calcification to the isotope information kept in foraminifer tests. Dissolution process of formaminifer test is characterized by thinning of their wall. Strong dissolution finally break the wall of tests, which leads to a positive skewness of weight distribution of perfect foraminifer tests, because imperfect (broken) test is not counted for weight measurement. It is discovered during this research that the skewness of weight distribution is a good semi-quantitative estimator of carbonate dissolution which is independent of secondary calcification. This fact enables us to estimate a true loss of primary calcite and addition of secondary calcite from the sediment core samples, and the objective of this study to improve the paleo-SST / SSS proxy using foraminifer tests is archieved.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), HOKKAIDO UNIVERSITY, 17540428
• High resolution reconstruction of hydrological cycle in the East Asia during the last deglaciation using terrestrial biomarkers
  Grants-in-Aid for Scientific Research
  2004 - 2006
  YAMAMOTO Masanobu; IRINO Tomohisa; TADA Ryuji; IKEHARA Minoru; OBA Tadamichi
  This study aims at examining the role of El Nino-Southern Oscillation in last deglacial warming and hydrological changes by reconstructing the latitudinal gradient of precipitation along the East Asian margin during the last deglaciation. For this purpose, we analyzed terrestrial biomarkers in marine cores from five different locations from the tropical to subarctic regions.
  Variations in lignin, terrestrial biomarkers and pollen compositions and biomarker-specific deuterium/hydrogen ratio indicated a dry climate in the regions north of 30 degrees north and an increase of precipitation at the site of 8 degrees north during the last deglaciation. This enhanced latitudinal gradient of precipitation was presumably caused by the combination of El Nino-like atmospheric pattern in the North Pacific and the intensified tropical convection.
  Other findings are as follows. The winter Aleutian Low was intensified during the last two deglaciations. Winter monsoon was stronger during the last deglaciation. The Holocene 1500-year oscillation was found in the sea surface temperature record from the Japan margin.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), HOKKAIDO UNIVERSITY, 16340158
• 有孔虫の殻内有機物を用いた地質時代の大気CO_2分圧プロキシの開発
  科学研究費助成事業
  2004 - 2005
  長谷川 卓; 入野 智久; 田崎 和江; 森下 知晃; 池原 実
  本年度は,有孔虫の殻に閉じ込められた有機物の含有量について,現生底生有孔虫,化石底生有孔虫(膠着質,石灰質),現生浮遊性有孔虫について分析を行った結果,約0.1-0.4%の含有量を持っていることが明らかになった.特に,浮遊性有孔虫ではその含有量の個体や種による差は小さいことがわかり,同位体分析のための適切な試料量が容易に推定できるようになった.そこに至るまでの過程で,様々な溶媒を用いたり,ふるいを自作するなどして効率的な準備方法を開発した.これらの作業は金沢大学で行った.
  これらの手法がほぼ確立したことを受け,実際に北海道大学地球環境科学研究院に設置の微量炭素の同位体比分析が可能な装置を用いて個別の種の浮遊性有孔虫(赤道太平洋の表層堆積物に含まれる現生浮遊性有孔虫)の殻構造内部に含まれる有機物の炭素同位体比を測定した(18年2月,3月).1個体の殻の重量が異なるため,分析に用いた有孔虫の個体数は種によって異なるが,Globorotalia menardiiでは100個体を用いて分析を行い,3回測定を繰り返すことができる程度の二酸化炭素ガスを得ることができた.Globigerinoides sacculiferでは400個体を用いることでほぼ同量のガスを得た.個別に処理したG.menardiiの4試料ではいずれも-24.35±0.3‰の範囲であった。このように開発した処理法は炭素同位体比の再現性が高いことが示すことができた.G.sacculiferでは1試料で-22.9‰,Globorotalia tumidaでは2試料から-23.72‰および-24.12%を得た.このように,種が異なっても同位体比値が大きく異なることがない.
  本研究の結果,有孔虫の殻体構造内に閉じ込められた有機炭素の同位体比分析の手法が確立した.今後,確立した手法を用いてデータを増やすことで,表層種と温度躍層種に系統的な差があるのかどうか,などが議論できる.また,実用面に関しては,限定した種を用いて有機炭素同位体比の経時変化を調べ,その炭酸塩炭素の同位体比との差を取り,その差が経時的にどのような変化を示すのか,を調査する次のステップに研究を進める段階に達した。
  日本学術振興会, 萌芽研究, 金沢大学, 16654080
• Study on Accumulation and Transportation of Refractory Organic Materials in Terrestrial Area
  Grants-in-Aid for Scientific Research
  2003 - 2005
  NAGAO Seiya; YAMAMOTO Masanobu; FUJITAKE Nobuhide; IRINO Tomohisa; KODAMA Hiroki
  An important part of global organic carbon cycle is the flux of terrestrial organic carbon from the continents to the oceans. The potential importance of coastal systems in global and regional organic budgets is still unclear because of the inherent complexity and variability of rivers, estuaries and coastal zones. Therefore, it is important to understand the organic matter cycling in estuaries and coastal systems, especially characteristics and dynamics of river DOM and POM. But the DOM and POM is not homogeneous in terms of size or chemical characteristics so that we can't evaluate the linkage of terrestrial and coastal environments. The objective of this study is to understand the transport behavior of dissolved and particulate organic matter from terrestrial region to ocean. This study used carbon isotopic ratios (Δ^<14>C and δ^<13>C values) as tracers of organic carbon because the simultaneous use of these values adds a second dimension to isotopic studies of carbon cycling in surface aquatic environments.
  Refractory organic materials, humic substances, were isolated from the river waters in Scotland, Ukraine, Japan and Indonesia by the XAD extraction. The Δ^<14>C values of dissolved humic substances ranged from -316‰ to +209‰, indicating spatial and temporal distribution.
  To understand transport of POM in river systems, we selected three river systems (Tokachi, Ishikari and Kuji River systems) with different watershed conditions and carried out the observation at a fixed point in each river. The Δ^<14>C values range from -111 to -286‰ for the Tokachi River in northeast Hokkaido, -103〜-364‰ for the Ishikari River in southeast Hokkaido and -18.7〜-94.4‰ for the Kuji River in Kanto area in Japan. The paired Δ^<14>C vs. δ^<13>C distributions vary with rivers and seasons. These results suggest that the difference in paired Δ^<14>C vs. δ^<13>C distributions may reflect the water discharge and watershed environments.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), HOKKAIDO UNIVERSITY, 15310002
• 河川懸濁粒子の量および組成観測に基づく河川流出量変動の海洋への影響の解明
  2004
  Competitive research funding
• Biogeochemical impact on marine environment from river discharge based on observation of river suspended materials
  2004
  Competitive research funding
• Chemical pproxy parametarization for evaluating prehistoric human activities.
  Grants-in-Aid for Scientific Research
  2001 - 2003
  MINAGAWA Masao; IRINO Tomohisa; NAGAO Seiya; YAMAMOTO Masanobu; MATSUI Akira; NISHIMOTO Tohohiro
  The purpose of this project is to prepare analytical procedures to identify a chemical evidence of human activities and to develop a chemical method to discriminate human remains from natural substances found in archeological sites. We focused organic compounds and stable isotope compositions, as both parameters are expected to characterize human agricultural activity and domestication of wild animals.
  Soil samples were collected from some archaeological sites, modern agricultural fields and natural fields. Some compounds in lipid fraction were extracted for identifying molecular composition by gas chromatography-mass spectrometer analysis. Stable carbon and nitrogen isotopes ratios were simultaneously studied to characterize biogeochemical perturbation of soil organic matter under taking agricultural activity. Bone collagen isotope analyses were also applied to discriminate domestication of Sus scrofa from wild boar populations.
  Soil organic matter analysis in modern agricultural field revealed that δ^<13>C and δ^<15>N of soil organic matter can be a useful proxy indicating C4 plants cultivation and consequent human perturbation of the soil microbe. Based on this result, soil samples from Bibi excavation site, a middle-Jomon sites in Chitose city, Hokkaido, evidences that there should be some kind treatment by prehistoric human at least 4,000 years, ago. In addition to this evidence molecular evidence by deoxycholic acids, a component of human bile, for soild lipid fraction also suggested likely usage of human leftover as fertilizer or toilet.
  Same analysis was applied to soil samples from burial site, Kamifukushima Nakamachi in Gunma prefecture, a lost village by a volcanic eruption in Edo era. Deoxycholic acid was detected closely in the soil from both a farm and manure sink in a farmer house, indicating that such molecules can be a promising proxy indicating manure treatment.
  Carbon and nitrogen isotope ratios of bone collagen were used to identify a individual of pigs from wild boar. We revealed that early domestication of boar could produce pigs having unusual isotopic patterns due to artificial feeding by human being, then it ca be useful proxy to detect early evidence of pig feeding.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), HOKKAIDO UNIVERSITY, 13308008
• High-resolution reconstruction of environmental change off the east coast of Japan since the last 50,000 years reconded in a marine sediment core.
  Grants-in-Aid for Scientific Research
  2001 - 2003
  OBA Tadamichi; YAMAMOTO Masanobu; NAGAO Seiya; OKADA Hisatake; NARITA Hisashi; IRINO Tomohisa
  The northwest Pacific, where the cold Oyashio and the warm Kuroshio Currents meet each other today, is the most sensitive region in the North Pacific for monitoring the migration of the western boundary corrects in response to the past climatic change. A long core (45.82 m length) was recovered from 2,224 m water depths off the central Japan during the IMAGES cruise in 2001. A multi-disciplinary study was carried out on the core by analyzing the following research items : color, grain size, mineral composition, paleomagnetism, δ^<18>O, δ^<13>C Opal, CaCO_3, species of diatoms, coccolithophorids, radiolaria, planktonic foraminifera and benthic foraminifera, CaCO_3 preservation, Uk37', TOC, C/N, δ^<13>C_, δ^<15>N_, biomakers and pollen. The following main results ware obtained. The δ^<18>O curve of G.bulloides is similar to the standard oxygen isotope curve, suggesting continuous deposition over the last 145 ka. All warm water indices yielded by the four microfossil assemblages (diatoms, coccolith, radiolaria, planktonic foraminifera) show temperature decreases during the MIS 2 and 6, and increases during the MIS 5, although their correlation coefficients with each other are not always high (between 0.5 and 0,6). The Alkenon-derived temperature (19℃) at the core top agrees with the mean annual SST at present time in this region. The SST at the end of the MIS 2 was 13℃, which is seen today about 4.5 degree latitude north than the core site. Similar migrations in SST are inferred from the coiling ratio of N.pachyderma. The C/N ratio, δ^<13>C_ and δ^<15>N_ indicate that the TOC is mainly of marine origin, although terrestrial origin slightly increases during the MIS 6. The curve of the warm pollen index is similar to the δ^<18>O curve of G.bulloides, except for the MIS 6 and 5e when the land temperature changes inferred from the pollen curve precede the δ^<18>O curve.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 13304040
• 海底細粒堆積物の粒度・鉱物・化学組成にもとづく供給源と運搬過程の解明
  2000
  Competitive research funding
• Provenance and transport process of fine grained marine sediments based on grain size, mineral, and chemical composition
  2000
  Competitive research funding
• 日本海・北西太平洋深海底堆積物への黄砂及び島弧起源砕屑物フラックスの時空変動復元
  科学研究費助成事業
  1998 - 1998
  入野 智久
  日本学術振興会, 特別研究員奨励費, 北海道大学, 96J01425