A5034094001- Geological formations and processes
- Geology and Paleoclimatology Research
- earthquake and tectonic studies
- Hydrology and Sediment Transport Processes
- Seismic Imaging and Inversion Techniques
- Methane Hydrates and Related Phenomena
- Geological and Geochemical Analysis
- Reservoir Engineering and Simulation Methods
- Geological and Geophysical Studies
- Paleontology and Stratigraphy of Fossils
- Hydrocarbon exploration and reservoir analysis
- Landslides and related hazards
- Aeolian processes and effects
- Hydraulic Fracturing and Reservoir Analysis
- Seismology and Earthquake Studies
- Soil erosion and sediment transport
- Geological Studies and Exploration
- Geochemistry and Geologic Mapping
- Coastal wetland ecosystem dynamics
- Geological Modeling and Analysis
- Planetary Science and Exploration
- Geophysical and Geoelectrical Methods
- Underwater Acoustics Research
- High-pressure geophysics and materials
- Oil and Gas Production Techniques
Kyoto University
2015-2024
Geological Survey of Japan
2020
Planetary Science Institute
2016-2019
Graduate School USA
2014-2018
Sphere Medical (United Kingdom)
2017-2018
Chiba University
2008-2015
Turbidity currents, and other types of submarine sediment densityflow, redistribute more acrossthe surface the Earth than any flow process, yet their concentration has never been measured directly in deep ocean.The depositsof these flows are societal importance as imperfect records past earthquakes tsunamogenic landslides reservoir rocks for many deep-water petroleum accumulations.Key future research directions on deposits were identified at an informal workshop September 2013.This...
Research Article| November 01, 2013 Tsunami-generated turbidity current of the 2011 Tohoku-Oki earthquake Kazuno Arai; Arai 1Department Earth Sciences, Graduate School Science, Chiba University, 1-33 Yayoicho, Inage-ku, 263-8522, Japan Search for other works by this author on: GSW Google Scholar Hajime Naruse; Naruse 2Division and Planetary Kyoto Kitashirakawa-Oiwakecho, Sakyo-ku, 606-8502, Ryo Miura; Miura 3Nippon Marine Enterprises, Ltd., 14-1 Ogawa-cho, Yokosuka, Kanagawa 238-0004,...
A self‐accelerating current is a particle‐driven gravity flow moving on sloping bottom whose velocity increases in the downstream direction as result of increasing suspended sediment concentration due to entrainment from bed. This implies that net balance between deposition onto bed and erosion into must be favorable latter; thus, larger mass particles being picked up suspension than settling out. The self‐accelerative stage cannot continue indefinitely. Either slope drops off point where...
Abstract This study reveals the three‐dimensional morphology and syn‐sedimentary formation processes of a deformation structure termed ‘truncated flame structures’ which is found in terrestrial tsunami deposit southern Thailand that formed during 2004 Indian Ocean Tsunami. The was at boundary between lower fine‐grained layer an upper coarse‐grained are related to two runup events. In order confirm structure, authors excavated trenches opencast pit. When viewed cross‐section oriented parallel...
Abstract Multiple‐layered tsunami deposits have been frequently reported from coastal stratigraphic sequences, but the formation processes of these layers remain uncertain. A terrestrial sandy deposit formed by 2004 Indian Ocean Tsunami was investigated at Ban Nam Kem, southern Thailand. Four internal induced two waves were identified in deposit. Sedimentary structures indicated that units run‐up currents caused and other deposited backwash flows. Graded bedding common layers, inverse...
Abstract Seismostratigraphy, coring, and logging while drilling during Integrated Ocean Drilling Program Expeditions 319, 322, 333 (Sites C0011/C0012) show three Miocene submarine fans in the NE Shikoku Basin, with broadly coeval deposits at Site 1177 Deep Sea Project 297 (NW Basin). The sediment dispersal patterns have major implications for paleogeographies that time. oldest, finer‐grained (Kyushu) fan has sheet‐like geometry; quartz‐rich flows were fed mostly from an ancestral landmass...
Understanding of the formative conditions fluvial bedforms is significant for both river management and geological studies. Diagrams showing bedform stability have been widely used analyses sedimentary structures. However, use discriminants to determine boundaries different regimes has not yet explored. In this study, we discriminant functions describe a range in 3‐D dimensionless parametric space. We do by means analysis using Mahalanobis distance. analyzed 3,793 available laboratory field...
Abstract. The 2011 Tohoku-oki tsunami inundated the Joban coastal area in Odaka region of city Minamisoma, up to 2818 m from shoreline. In this study, flow characteristics were reconstructed deposits using DNN (deep neural network) inverse model, suggesting that inundation occurred Froude supercritical condition. model effectively estimated parameters region, including maximum distance, velocity, depth, and sediment concentration. Despite having a few topographical anthropogenic undulations...
Abstract Measurements of thickness and grain size along flow‐parallel transects across onshore deposits the 2004 Indian Ocean tsunami revealed macroscopic horizontal variations provided new insights into sedimentation. The caused severe erosion beaches, river mouths, shallow seafloor coast southwestern Thailand supplied sufficient sediment to deposit a kilometer‐wide blanket sand on land surface. generally fine landward with some fluctuations by local entrainment settlement sediments....
Abstract During IODP Expedition 322, an interval of Late Miocene (7.6 to ∼9.1 Ma) tuffaceous and volcaniclastic sandstones was discovered in the Shikoku Basin (Site C0011B), Nankai region. This consists bioturbated silty claystone including four 1–7 m thick interbeds (TST) containing 57–82% (by volume) pyroclasts. We use major trace element glass compositions, as well radiogenic isotope show that beds derived from single eruptive events, majority (TST 1, 2, 3a) came different eruptions a...
Tsunami deposits provide important clues to understand ancient tsunami events. Several inverse models have been proposed estimate the magnitude of paleotsunamis from their deposits. However, existing consider neither nonuniform transport suspended sediment nor turbulent mixing, which are essential factors governing sedimentation suspension in flows. Here we propose a new model deposit emplacement, considering both load and entrainment basal sediments. This inversion requires spatial...
In Rikuzentakata City, Ostracode assemblages in sediment deposited by the Tohoku‐Oki earthquake and tsunami of 11 March 2011 revealed that was derived from seafloor at least 9 m water depth, transported inland more than 1 km. The wave height this location higher 10 m. Four hundred fifty seven modern ostracode were used analogue technique to estimate depth source assemblages. application method paleo‐tsunami deposits may provide insight into past potentially slip magnitude.
Details of the three-dimensional morphology ichnofossil Phycosiphon incertum collected from deposits on submarine slopes are reconstructed by processing a series images obtained polished sections samples. Samples were mudstone around slump scar in Paleocene Shiomi Formation, northern Japan, which is characterized occurrence scars. The meandering tube with flattened ellipse cross section. tubes plane oblique to bedding surfaces and aligned along same direction at both interior exterior scar....
Tsunami deposits provide information for estimating the magnitude and flow conditions of paleotsunamis, inverse models have potential reconstructing hydraulic tsunamis from their deposits. The majority previously proposed are based on oversimplified assumptions possess some limitations. We present a new model FITTNUSS model, which incorporates nonuniform unsteady transport suspended sediment turbulent mixing. uses deep neural network (DNN) inversion method. In this method, forward...
Abstract. The 2004 Indian Ocean tsunami caused significant economic losses and a large number of fatalities in the coastal areas. estimation flow conditions using inverse models has become fundamental aspect disaster mitigation management. Here, case study involving Phra Thong island, which was affected by tsunami, Thailand conducted modeling that incorporates deep neural network (DNN). DNN analysis reconstructed values such as maximum inundation distance, velocity depth, well sediment...
"Consider the [turbidity] current as ... a river" R. A. Bagnold (1962); foundation of contemporary deep marine sedimentology. Gravity currents, such sediment-laden turbidity are ubiquitous natural flows that driven by density difference. Turbidity currents have provided vital motivation to advance understanding this class because their enigmatic long run-out and driving mechanisms not properly understood. Extant models assume material transport gravity is dynamically similar fluvial flows....
Abstract The profile of a river that conveys sediment without net deposition and erosion is referred to as ‘graded’ with respect vertical aggradation the segment. Three experimental series, designed in terms autostratigraphic view alluvial grade, were conducted clarify diagnostic spatial behaviour graded alluvial–deltaic rivers: an ‘R series’, which utilized moving boundary setting stationary base level; ‘F series’ fixed level produce ‘forced grade’; ‘M constant base‐level fall ‘autogenic...