研究等業績 - 原著論文 - Stephen P. Obrochta

A new model of Holocene reef initiation and growth in response to sea-level rise on the Southern Great Barrier Reef

Sanborn, K.L., Webster, J.M., Webb, G.E., Braga, J.C., Humblet, M., Nothdurft, L., Patterson, M.A., Dechnik, B., Warner, S., Graham, T., Murphy, R.J., Yokoyama, Y., Obrochta, S.P., Zhao, J.-X., Salas-Saavedra, M.

Sedimentary Geology   397   2020年03月  [査読有り]

研究論文（学術雑誌）   国際共著

The fossil record provides valuable data for improving our understanding of both past and future reef resilience and vulnerability to environmental change. The spatial and temporal pattern of the initiation of the Holocene Great Barrier Reef presents a case study of reef response to rapid sea-level rise. Past studies have been limited by the lack of well-dated and closely spaced reef core transects and have not closely examined the composition of the reef-building communities through time. This study presents 80 new high precision U-Th and 5 radiocarbon ages from twelve new cores located along three transects across different geomorphic and hydrodynamic settings of One Tree Reef, southern Great Barrier Reef, to document three distinct stages of Holocene reef development in unprecedented detail. Temporal constraints on changing paleoecological assemblages of coral, coralline algae and associated biota revealed three distinct phases of reef development, consisting of: 1)a fast, shallow and clear-water reef initiation from 8.2 until 8 ka; 2)a shift to slower, deeper and more turbid-water reef growth from 8 to 7 ka; and 3)a return to shallow and rapid branching coral growth in clear-water conditions as the reef "catches up" to sea-level. A minimum lag prior to reef initiation of 700 years was identified, which differs in length depending on reef environment and Pleistocene substrate height. In this new model, reef growth initiated on the topographically lower leeward margin and patch reef, prior to the start of windward margin development, contrary to the traditional reef growth model. While there was a shift to conditions less favorable for reef growth at 8 ka, this did not prevent the slow accretion of more sediment-tolerant coral communities. The majority of the reef reached sea level by similar to 6 ka. This new conceptual model of Holocene reef growth provides new constraints on changes in paleoenvironment that controlled reef community composition and growth trajectories through sea-level rise following inundation. (C) 2019 Elsevier B.V. All rights reserved.

DOI

Tsunami deposits refine great earthquake rupture extent and recurrence over the past 1300 years along the Nankai and Tokai fault segments of the Nankai Trough, Japan

Osamu Fujiwara, Akira Aoshima, Toshiaki Irizuki, Eisuke Ono, Stephen P. Obrochta, Yoshikazu Sampei, Yoshiki Sato, Ayumi Takahashi

Quaternary Science Reviews   227   2020年01月  [査読有り]

研究論文（学術雑誌）   国内共著

© 2019 Elsevier Ltd Study of prehistoric to medieval-age tsunami deposits along a riverbank site near the eastern Nankai Trough, central Japan, show that, not only did Tokai earthquakes occur with a higher frequency than previously thought, but that contemporaneous ruptures of the Tokai and Nankai fault segments were also more common. The site revealed a ∼1-km long coast-normal cross section of the strand plain and exposed four sandy tsunami deposits, each of which indicates inundation over 2 km inland of the coast. Radiocarbon dating of previously studied and newly discovered deposits in the region indicates a shorter recurrence time for Tokai earthquakes and clarifies their linkage with Nankai earthquakes. We attribute the younger two tsunami deposits to the 1498 and 1096 CE Tokai earthquakes. The older two deposits confirm the occurrence of the Tokai earthquakes in 887 CE and in the latest 7th century. These events are not reliably recorded in historical documents in the Tokai region but were noted in the Nankai area. The 887 CE earthquake likely represents a full-length rupture of the Tokai and Nankai segments, as was the case for the 1707 CE earthquake. Integrated with the previous studies, these new results show that nine Tokai earthquakes occurred over the last 1300 years, the oldest in the latest 7th century, and in 887, 1096, 1361, 1498, 1614, 1707, 1854 and 1944 CE. Recalculated recurrence intervals range from 90 to 265 years. Except for the 1498 Meio Tokai earthquake, the Tokai earthquakes occurred simultaneously with Nankai earthquakes.

DOI

Organic carbon accumulation and productivity over the past 130 years in Lake Kawaguchi (central Japan) reconstructed using organic geochemical proxies

Yamamoto, S., Hubert-Ferrari, A., Lamair, L., Miyata, Y., Ochiai, S., Nagao, S., Miyauchi, N., Yoshida, K., Fujiwara, O., Yokoyama, Y., Heyvaert, V.M.A., De Batist, M., Boes, E., Brückner, H., De Rycker, K., Garrett, E., Miyairi, Y., Nakamura, A., Obrochta, S., Riedesel, S., Shishikura, M., Walstra, J., The QuakeRecNankai Team

Journal of Paleolimnology     2020年  [査読有り]

研究論文（学術雑誌）   国内共著

DOI

A Rapid, Deterministic Age-Depth Modeling Routine for Geological Sequences With Inherent Depth Uncertainty

Lougheed, B.C, Obrochta, S, P

Paleoceanography and Paleoclimatology ( Paleoceanography and Paleoclimatology )  34 ( 1 ) 122 - 133   2019年01月  [査読有り]

研究論文（学術雑誌）   国際共著

DOI

本栖湖の湖底堆積物の精密な放射性炭素 年代測定が明らかにする富士山の噴火史

Stephen Obrochta, 藤原 治, 横山 祐典, 宮入 陽介

Isotope News   763   22 - 25   2019年06月

研究論文（学術雑誌）   国内共著

Mt. Fuji Holocene eruption history reconstructed from proximal lake sediments and high-density radiocarbon dating

Obrochta, S.P., Yokoyama, Y., Yoshimoto, M., Yamamoto, S., Miyairi, Y, Nagano, G., Nakamura, A, Tsunematsu, K, Lamair, L, Hubert-Ferrari, A, Lougheed, B.C., Hokanishi, A., Yasuda, A., Heyvaert, V. M. A., De Batist, M., Fujiwara, O, and the QuakeRecNankai Team

Quaternary Science Reviews   200   395 - 405   2018年10月  [査読有り]

研究論文（学術雑誌）   国内共著

DOI

Late Weichselian to Holocene history of the Baltic Sea as reflected in ostracod assemblages

Stepanova, A., Obrochta, S.P., Quintana Krupinski, N., Hyttinen, O., Kotilainen, A., Andrén,T.

Boreas   48   761 - 778   2019年07月  [査読有り]

研究論文（学術雑誌）   国際共著

DOI

湖底堆積物から探る富士山の噴火史 -本栖湖に残されていた未知の噴火の発見-

藤原治, Stephen Obrochta, 横山祐典, 宮入陽介, 常松佳恵

GSJ 地質ニュース   8 ( 3 ) 66 - 69   2019年01月

研究論文（学術雑誌）   国内共著

Response of the Great Barrier Reef to sea-level and environmental changes over the past 30,000 years

Jody M. Webster, Juan Carlos Braga, Marc Humblet, Donald C. Potts, Yasufumi Iryu, Yusuke Yokoyama, Kazuhiko Fujita, Raphael Bourillot, Tezer M. Esat, Stewart Fallon, William G. Thompson, Alexander L. Thomas, Hironobu Kan, Helen V. McGregor, Gustavo Hinestrosa, Stephen P. Obrochta, Bryan C. Lougheed

Nature Geoscience   11   426 - 432   2018年05月  [査読有り]

研究論文（学術雑誌）   国際共著

DOI

A sea-level plateau preceding the Marine Isotope Stage 2 minima revealed by Australian sediments

Ishiwa, T., Yokoyama, Y., Okuno, J., Obrochta, S.P., Uehara, K., Ikehara, M., Miyairi, Y.

Scientific Reports   9 ( 1 )   2019年01月  [査読有り]

研究論文（学術雑誌）   国内共著

DOI

Coring induced sediment fabrics at IODP Expedition 347 Sites M0061 and M0062 identified by anisotropy of magnetic susceptibility (AMS): criteria for accepting palaeomagnetic data

Snowball, I., Almqvist, B., Lougheed, B C., Wiers, S., Obrochta, S., Herrero-Bervera, E.

Geophysical Journal International   217 ( 2 ) 1089 - 1107   2019年02月  [査読有り]

研究論文（学術雑誌）   国際共著

DOI

Use of high-resolution seismic reflection data for paleogeographical reconstruction of shallow Lake Yamanaka (Fuji Five Lakes, Japan)

Lamair, L., Hubert-Ferrari, A., Yamamoto, S., Fujiwara, O., Yokoyama, Y., Garrett, E., De Batist, M., Heyvaert, V.M.A., Boes, Evelien, Nakamura, Atsunori, Obrochta, Stephen, Shishikura, Masanobu, Miyairi, Yosuke, Brückner, Helmut, Ono, Eisuke, Riedesel, Svenja, De Rycker, Koen, Sato, Yoshiki, Walstra, Jan

Palaeogeography, Palaeoclimatology, Palaeoecology   514   233 - 250   2019年01月  [査読有り]

研究論文（学術雑誌）   国際共著

DOI

Microbial biomass turnover times and clues to cellular protein repair in energy-limited deep Baltic Sea sediments

Mahtre, S, Kaufmann, S, Marshall, I.P.G., Obrochta, S.P., Andren, T., Jørgensen, B.B, Lomstein, B.A.

FEMS Microbiology Ecology   95 ( 6 )   2019年05月  [査読有り]

研究論文（学術雑誌）   国際共著

DOI

Assessment of northeastern Japan tree-ring oxygen isotopes for reconstructing early summer hydroclimate and spring Arctic Oscillation

Wataru Sakashita, Yusuke Yokoyama, Hiroko Miyahara, Takahiro Aze, Stephen P. Obrochta, Motonari Ohyama, and Hitoshi Yonenobu

Geochemistry, Geophysics, Geosystems   19 ( 3520 ) 3528   2018年09月  [査読有り]

研究論文（学術雑誌）   国内共著

DOI

The undatables: Quantifying uncertainty in a highly expanded Late Glacial - Holocene sediment sequence recovered from the deepest Baltic Sea basin - IODP Site M0063

Stephen P. Obrochta, Thomas Andrén, Szilárd Z. Fazeka, Bryan C. Lougheed, Ian Snowball, Yusuke Yokoyama, Yosuke Miyairi, Reisuke Kondo, Aarno, T. Kotilainen, Outi Hyttinen, and Annick Fehr

Geochemistry, Geophysics, Geosystems   18   2017年02月  [査読有り]

研究論文（学術雑誌）   国際共著

DOI

Bulk sediment 14C dating in an estuarine environment - How accurate can it be?

Bryan C. Lougheed, Stephen P. Obrochta, Conny Lenz, Anette Mellström, Brett Metcalfe, Raimund Muscheler, Maja Rinholdsson, Ian Snowball Lovisa Zillén

Paleoceanography   32   2017年02月  [査読有り]

研究論文（学術雑誌）   国際共著

DOI

MatCal: Open Source Bayesian 14C Age Calibration in Matlab

Bryan C. Lougheed, Stephen P. Obrochta

Journal of Open Research Software   4 ( 1 )   2016年11月  [査読有り]

研究論文（学術雑誌）   国際共著

DOI

Relationship between the Northern Pacific Gyre Oscillation and tree-ring cellulose oxygen isotopes in northeastern Japan

Sakasita, W., Miyahara, H., Yokoyama, Y., Axe, T., Obrochta, S.P., and Nakatsuka, T.

Geoscience Letters   4 ( 29 )   2017年12月  [査読有り]

研究論文（学術雑誌）   国内共著

DOI

Volcanic influence of Mt. Fuji on the watershed of Lake Motosu and its impact on the lacustrine sedimentary record

Laura Lamair, Aurélia Hubert-Ferrari, Yamamoto Shinya, Meriam El Ouahabi, Jacqueline Vander Auwera, Stephen P. Obrochta, Evelien Boes, Atsunori Nakamura, Osamu Fujiwara, Masanobu Shishikura, Sabine Schmidt, Giuseppe Siani, Yosuke Miyairi, Yusuke Yokoyama, Marc De Batist, Vanessa M.A. Heyvaert, and the QuakeRecNankai Team

Sedimentary Geology   363   200 - 220   2018年01月  [査読有り]

研究論文（学術雑誌）   国際共著

DOI

Seasonal hypoxia was a natural feature of the coastal zone in the Little Belt, Denmark, during the past 8ka

van Helmond, Niels A.G.M., Quintana Krupinski, Nadine B., Lougheed, Bryan C., Obrochta, Stephen P., Andrén, Thomas, Slomp, Caroline P.,

Marine Geology   387   45 - 57   2017年05月  [査読有り]

研究論文（学術雑誌）   国際共著

DOI