Papers - Niwa, Yuichi

東北地方太平洋岸南部・真野川低地における完新世の堆積環境変化と地殻変動傾向

丹羽雄一，須貝俊彦

地学雑誌 133   169 - 193 2024.06

Research paper (scientific journal), Joint Work, Lead author, Corresponding author, Accepted

Radiocarbon reservoir ages in the Holocene sediments off the Sanriku coast, Northeast Japan

Nakanishi T., Niwa Y., Hong W.

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms (Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms)  538   95 - 102 2023.05

ISSN  0168583X

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To investigate the relationship between paleoenvironmental changes and marine reservoir effects, the radiocarbon ages of marine shells and terrestrial plants from the same horizons of sediment cores in the Holocene Epoch were compared. Three sediment cores were obtained from the central to northern parts of the Sanriku coast, corresponding to the boundary between the warm Kuroshio and cold Oyashio currents. These drilling sites are also located in a tectonically active area associated with the subduction of the Pacific Plate in Japan Trench. Based on lithological analysis, molluscan assemblage investigation, and radiocarbon dating, we interpreted five sedimentary facies. These paleoenvironmental changes were mainly related to sea level rise during the last deglaciation period. Reservoir ages from 33 pairs of terrestrial plants and marine shells (420 ± 130 14C years) were found to span the period from 2,300 to 9,000 cal BP.

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青森県・八戸平野における地形分類図と洪水ハザードマップの比較

丹羽 雄一，須貝俊彦

地学雑誌 131   557 - 563 2022.10

Research paper (scientific journal), Joint Work, Accepted

Millennial-scale vertical deformation of the Hachinohe coastal plain (NE Japan)

Niwa, Y., Sugai, T.

Geomorphology (Geomorphology)  389 2021.06

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0169555X

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We report geomorphological and sedimentological analyses in the Hachinohe plain (northernmost Sanriku coast, NE Japan) that yield new insights into vertical deformation around the source region of the 2011 Tohoku-oki earthquake. Landform classification and analyses of seven sediment cores document the transgression and regression of a sandy barrier and back-barrier estuary in a wave-dominated estuary system during the Holocene. We compare the heights of (i) the earliest Holocene marine flooding surface overlying fluvial sediments and (ii) the onset of a Middle Holocene marsh environment with non-tectonic hydro-isostatic sea-level predictions to constrain the millennial-scale vertical deformation rate in the Hachinohe plain to within −0.7 to +0.7 mm/yr (uplift positive). This result is in contrast to observed subsidence along the central to southern Sanriku coast but is consistent with relative uplift along the northern Sanriku coast. Our results support deformation characterized by southward tilting along the Sanriku coast during the last 100 kyr as suggested by previous studies south of Hachinohe. Furthermore, this tectonic pattern is consistent with deformation trends before and during the 2011 Tohoku-oki earthquake. This collective consistency implies that the effects of subduction and megathrust slip on coastal deformation have persisted for at least 100 kyr around the source region of the 2011 earthquake.

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An assessment of coastal tectonics along the Sanriku coast, northeast Japan, from a Holocene sedimentary succession in the Kuji plain

Niwa, Y., Sugai, T.

Marine Geology 424 2020.03

Research paper (scientific journal), Accepted

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Millennial-scale crustal movements inferred from Holocene sedimentary succession of the Omoto plain, northern Sanriku coast, Northeast Japan: Relevance for modeling megathrust earthquake cycles

Niwa, Y., Sugai, T., Matsushima, Y., Toda, S.

Quaternary International 519   10 - 24 2019.09

Research paper (scientific journal), Joint Work, Accepted

三陸海岸における地震サイクル解明に向けた地形・地質研究の現状と課題

丹羽雄一

第四紀研究 58   3 - 11 2019.01

Research paper (scientific journal), Single Work, Accepted

神城断層の極浅部における断層形状と平均上下変位速度：長野県北安曇郡白馬村神城地区におけるボーリング調査

丹羽雄一,遠田晋次,石村大輔,森 良樹,小俣雅志

活断層研究 49   1 - 16 2018.11

Research paper (scientific journal), Joint Work, Accepted

三陸海岸・山田平野で得られたコア堆積物の特徴と年代

丹羽雄一,須貝俊彦,山市 剛,松島義章,松崎浩之

地学雑誌 127   89 - 100 2018.02

Research paper (scientific journal), Accepted

Subsidence along the central to southern Sanriku coast, northeast Japan, near the source region of the 2011 Tohoku-oki earthquake, estimated from the Holocene sedimentary succession along a ria coast

Niwa, Y., Sugai, T., Matsushima, Y., Toda, S.

Quaternary International 456   1 - 16 2017.10

Research paper (scientific journal), Joint Work, Accepted

Influence of deposition in dam reservoir on the deep marine hemipelagic environment off Niigata, central Japan

Shirai, M., Utsugawa, T., Omura, A., Hayashizaki, R., Kameo, K., Niwa, Y., Shimizu, H.

Environmental Earth Science  2017

Research paper (scientific journal), Joint Work, Accepted

三陸海岸南部の完新世沈降を支持する堆積環境：津谷平野で得られたコア試料の堆積相と年代

丹羽雄一,須貝俊彦,松島義章

地学雑誌 125   395 - 407 2016.06

Research paper (scientific journal), Joint Work, Accepted

三陸海岸南部・気仙沼大川平野の地形発達過程

丹羽雄一,須貝俊彦,松島義章,松崎浩之

地形 36   253 - 270 2015.10

Research paper (scientific journal), Joint Work, Accepted

2014年11月22日長野県北部の地震（Mw 6.2）によって出現した神城断層沿いの地表地震断層の分布と性状

石村大輔,岡田真介,丹羽雄一,遠田晋次

活断層研究 43   95 - 108 2015.09

Research paper (scientific journal), Joint Work, Accepted

三陸海岸南部・気仙沼大川平野の完新世における地殻変動

丹羽雄一,須貝俊彦,松島義章

地学雑誌 124   545 - 560 2015.08

Research paper (scientific journal), Joint Work, Accepted

The first surface-rupturing earthquake in 20 years on a HERP active fault is not 'characteristic:' The 2014 Mw=6.2 Nagano event along the northern Itoigawa-Shizuoka Tectonic Line

Okada, S., Ishimura, D., Niwa, Y., Toda, S.

Seismological Research Letters 86 2015.08

Research paper (scientific journal), Joint Work, Accepted

陸前高田平野完新統の堆積相・堆積速度および推定される地殻変動傾向

丹羽雄一,遠田晋次,須貝俊彦,松島義章

第四紀研究 53   311 - 322 2014.12

Research paper (scientific journal), Joint Work, Accepted

Depositional age of event sand layers apparent in upper Holocene sequence across the Kuwana fault, southwestern Nobi plain, central Japan

Niwa, Y., Sugai, T., Matsuzaki, H.

Science Reports of Tohoku University 7th Series (Geography) 60   97 - 108 2014.12

Research paper (bulletin of university, research institution), Joint Work

井戸沢断層の 2011 年福島県浜通りの地震に先行する断層活動：福島県いわき市塩ノ平地区におけるボーリング調査

丹羽雄一,遠田晋次,小俣雅志,森 良樹

活断層研究 39   1 - 8 2013.09

Research paper (scientific journal), Joint Work, Accepted

Activity of the Yoro fault system determined from coseismic subsidence events recorded in the Holocene delta sequence of the Nobi plain, central Japan.

Niwa, Y., Sugai, T., Yasue, K.

Bulletin of the Seismological Society of America 102   1120 - 1134 2012.06

Research paper (scientific journal), Joint Work, Accepted