A5102795337- earthquake and tectonic studies
- Geology and Paleoclimatology Research
- Earthquake and Disaster Impact Studies
- Earthquake and Tsunami Effects
- Methane Hydrates and Related Phenomena
- Seismology and Earthquake Studies
- Landslides and related hazards
- Geological formations and processes
- Geological and Geochemical Analysis
- Cryospheric studies and observations
- Evolution and Paleontology Studies
- Geological Modeling and Analysis
- Pleistocene-Era Hominins and Archaeology
- Archaeology and ancient environmental studies
- Seismic Performance and Analysis
- Geological and Geophysical Studies
- Primate Behavior and Ecology
- Flood Risk Assessment and Management
- Isotope Analysis in Ecology
- Marine and coastal ecosystems
- Aeolian processes and effects
- Microbial Community Ecology and Physiology
- Tree-ring climate responses
- Disaster Management and Resilience
- Seismic Waves and Analysis
Niigata University
2014-2024
Research Article| September 01, 2008 Breakout flood from an ignimbrite-dammed valley after the 5 ka Numazawako eruption, northeast Japan Kyoko S. Kataoka; Kataoka † 1Research Center for Natural Hazards and Disaster Recovery, Niigata University, Ikarashi 2-cho 8050, Nishi-ku, 950-2181, †E-mail: kataoka@gs.niigata-u.ac.jp Search other works by this author on: GSW Google Scholar Atsushi Urabe; Urabe Vern Manville; Manville 2GNS Science, Wairakei Centre, Private Bag 2000, Taupo, New Zealand...
The Niigata (Echigo) Plain facing the Sea of Japan is located downstream two large rivers (the Shinano-gawa River and Agano-gawa River), has three sand dune ridges which formed along coastal areas during Holocene. city, with a population ~770,000, lies in lower catchment alluvial-coastal system. Despite city being approximately 160 km away from epicenter January 1st 2024 Mw 7.6 Noto Peninsula Earthquake, extensive damage to houses, buildings, infrastructure occurred throughout due pervasive...
Lake-level changes inferred from seismic surveying and core sampling of the floor Lake Baikal near Selenga River delta can be used to constrain regional climatic history appear correlated global climate represented by marine oxygen isotope stages (MIS). The reflection pattern correlation indicate that topset progradational foreset sediments deltas formed during periods stable lake levels warm conditions. During stages, level was high, cold it low. drop in due cooling MIS 5 through 4 is...
平成27年9月関東・東北豪雨により鬼怒川中流域の常総市上三坂地区で生じた人工堤防の決壊による堆積物について,トレンチ掘削や粒度分析を行い,その堆積学的特徴を明らかにした.破堤堆積物は全体的に細粒砂〜中粒砂を主体とし,下位から順に,上方粗粒化を示す細粒砂層(ユニットA),上方細粒化を示す細粒砂〜中粒砂層(ユニットB),低角斜交層理や平行葉理の発達する細粒〜中粒砂層(ユニットC)に細分される.各堆積ユニットは,鬼怒川の越水,破堤,さらに河川水が氾濫原に流入した後,氾濫が収束するという一連の堆積プロセスを反映していると推定される.ユニットAは越水による氾濫堆積の特徴としてよく知られているものである.今回の破堤堆積物では,その上に上方細粒化するユニットBが重なることが特徴である.
日本海東縁の沿岸域では,津波起源とされるイベント堆積物の報告が急増している.その時間-空間分布を整理し,地域間の対比と推定される波源を提示した.19~18世紀にはいくつかの歴史津波が知られ,地点数は多くないが対応するイベント堆積物が報告されている.18世紀以前は歴史記録に乏しいが,イベント堆積物から14~9世紀の間に次の4つの津波イベントの存在が示唆される-14世紀:青森~山形北部,12世紀:北海道南西部,11世紀(西暦1092年?):佐渡/新潟~山形南部,9世紀(西暦850年?):(佐渡~)山形~青森-.これらのイベントは日本海盆の地震性タービダイトにも記録されている.より古いイベント堆積物は,奥尻島や佐渡島などの離島で認められている.現時点では堆積物の起源の認定や正確な年代決定などに多くの問題が残っており,この総説が今後の問題点の解決と日本海東縁の古津波像解明の一助となることを期待する.
This article describes a method for processing microtremor records from small-scale seismic array that allows interval-averaged S-wave velocities to be estimated 10-m depth ranges down of 30 m. The was applied data obtained in the town Mashiki, Kumamoto Prefecture, Japan, and analysis results were evaluated through comparison with available PS logs sections by surface-wave methods. It turned out velocity estimates may subject errors up 20–30% absolute values, but it shown can help evaluate...
北海道南西部奥尻島南端の低地における掘削調査から,泥炭層中に5枚のイベント堆積物を見出した.イベント堆積物の特徴は次の通りである; (1)陸方向および川から離れる方向へ薄層化・細粒化する,(2)級化層理を示す,(3)粒度組成の特徴は河床砂とは異なり,海浜砂に類似する,(4)粒子ファブリックおよび堆積構造から推定される古流向は概ね陸方向を示す,(5)渦鞭毛藻シストおよび底生有孔虫の有機質内膜が産出する,(6)海側前面に標高の高い沿岸砂丘が発達する閉塞した地形において,現海岸線から内陸へ最大450mほど離れた場所まで分布する.以上の地質・地形学的特徴に加え,過去に高潮が調査地域に浸水した記録は認められないことから,イベント堆積物は津波起源である可能性が極めて高い.14C年代測定結果と合わせて考えると,過去3000-4000年の間に1741年および1993年を含めて少なくとも6回の津波が発生しているものと考えられる.
The 2011 off the Pacific coast of Tohoku Earthquake caused significant liquefaction in Kanto district. Many houses, roads, and lifelines were damaged due to liquefaction. Serious damages occurred artificial filled land Hinode area Itako City. We investigated house damage by conducted a borehole survey area. results show that sand layer man-made strata pomp system. It was revealed differences relate thickness grain size distribution dredged strata. examination grainsize analysis stratum with...
越後平野は,日本海に面した沖積低地で複数の砂丘列が発達している.平野部の阿賀野川流域の沖積層において,複数のボーリング試料の堆積相や構成鉱物の特徴から,約5000年前の沼沢湖噴火によるラハール堆積物の堆積過程を検討した.ラハールによる堆積物は,当時の海岸部では層厚5~8 m程度の軽石質なデルタを形成した.また,決壊洪水イベントによる膨大な量の火砕物は,デルタシステムを急速に前進させ海岸地形を変化させた.このような大規模な火砕物の再堆積作用の解明は,平野の形成過程における影響だけでなく,下流域での火山土砂災害としての予測につながる課題となるものである.
Numerous progress has been made in the field of applied photogrammetry last decade, including usage close-range as a mean conservation and record outcrops. In present contribution, we use SfM-MVS method combined with wavelet decomposition analysis surface, order to relate it morphological surface roughness data. The results demonstrated that RMS could provide rapid insight on location coarser materials individual outliers, while arithmetic were more useful detect units or layers are similar...
Late Quaternary strath terraces younger than 50ka were investigated in the Shitada (Ikarashi River) and Tochio (Kariyada regions, central eastern margin of Niigata Basin, order to clarify their chronology implications neotectonic movements. The classified based on geomorphologic configuration tephro-stratigraphic relation between marker tephra horizons terraces. Six (ST 1-ST 6) found loam black soil, which overlie terrace deposits. ST 4 is correlated with widespread As-K (13ka), 5 AT (25ka)...
越後平野は，日本海に面した信濃川と阿賀野川の下流に発達する海岸平野であり，複数の砂丘列が発達する．このうち，越後平野の阿賀野川沿いでボーリングを行い，堆積相と堆積システムの復元を行った．この結果，この地域は，デルタシステムを基礎として形成されていることが明らかとなった．越後平野の堆積システムは，新潟市西部の信濃川沿いではバリアー-ラグーンシステム，新潟市東部の阿賀野川下流ではデルタシステムが成立していたと考えられ，越後平野の沖積層は，2つの異なる堆積システムの前進により形成されたことが明らかとなった．
Abstract Two-thirds of the 111 active volcanoes in Japan are covered with snow for several months during winter and demonstrate high hazard risk potentials associated snow-related lahars after eruptions. On 23 January 2018, a sudden phreatic eruption occurred at ski field on Kusatsu-Shirane (Mt. Motoshirane) volcano, Japan. This new vent from snow-clad pyroclastic cone required forecasting future crisis hazards zonation downslope areas including Kusatsu town, popular tourist site skiing hot...
The 2011 off the Pacific coast of Tohoku earthquake caused severe liquefaction events in Kanto region, which is 300-400 km south earthquake's epicenter. All-core drillings and trenching surveys were carried out at Yodaura Mukoya, are situated lowland along lower Tone River central region. site on reclaimed land where a former lake was filled by sand pumping from 1969 to 1974. sediments consisted silts clays Lake deposits (natural sediments) sandy strata composed artificial fill. No evidence...
Abstract Deposits of the AD1741 Oshima-Ohshima tsunami and some other events were identified by pit excavations in two narrow coastal lowlands along eastern margin Japan Sea, northern Hiyama District, Hokkaido, Japan. The deposits consisted volcanic-ash sand grains derived from AD1640 Ko-d tephra, characterized landward thinning bed geometry, paleocurrent, normal grading, erosional base with rip-up clasts, higher ratio marine diatoms. In Kumaishi-Ayukawa lowland, well-preserved out-flow...