A5067050014- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Isotope Analysis in Ecology
- Geological formations and processes
- Aeolian processes and effects
- earthquake and tectonic studies
- Geological and Geochemical Analysis
- Geological Studies and Exploration
- Cryospheric studies and observations
- Hydrocarbon exploration and reservoir analysis
- Paleontology and Stratigraphy of Fossils
- Earthquake Detection and Analysis
- Astro and Planetary Science
- Atmospheric chemistry and aerosols
- Lymphoma Diagnosis and Treatment
- Marine and coastal ecosystems
- Geochemistry and Elemental Analysis
- Hydrology and Watershed Management Studies
- Solar and Space Plasma Dynamics
- Marine and Coastal Research
- Flood Risk Assessment and Management
- Solar Radiation and Photovoltaics
- Tree-ring climate responses
- Geomagnetism and Paleomagnetism Studies
- Pacific and Southeast Asian Studies
Japan Agency for Marine-Earth Science and Technology
2016-2025
Sapporo Medical University
2020
Tokyo Metropolitan University
2017
Osaka University
2010-2012
V.I. Il'ichev Pacific Oceanological Institute
2012
Nagoya University
2012
Kyushu University
2012
Newcastle University
2012
The University of Tokyo
2004
The causes of spatial and temporal changes in East Asian summer monsoon (EASM) precipitation on millennial to multimillennial time scales during the Holocene have not yet been resolved. Here, we examine relationship between variations EASM westerly jet (WJ) path over Asia using provenance eolian dust Japan Sea sediments, which interpret reflect WJ and/or surface conditions desert areas. contribution from Mongolian Gobi Desert relative that Taklimakan shows millennial‐scale...
Terrestrial glacial records from the Patagonian Andes and New Zealand Alps document quasi-synchronous Southern Hemisphere–wide glacier advances during late Quaternary. However, these are inherently incomplete. Here, we provide a continuous marine record of western–central ice sheet (PIS) extent over complete glacial–interglacial cycle back into penultimate (~140 ka). Sediment core MR16-09 PC03, located at 46°S ~150 km offshore Chile, received high terrestrial sediment meltwater input when...
Millennial‐scale variability in the behavior of North Pacific Intermediate Water during last glacial and deglacial period, its association with Dansgaard‐Oeschger (D‐O) cycles Heinrich events, are examined based on benthic foraminiferal oxygen carbon isotopes ( δ 18 O bf 13 C ) %CaCO 3 using a sediment core recovered from northeastern slope Bering Sea. A suite positive excursions at intermediate depths Sea, which seem least part associated increases gradients between Okhotsk Seas, suggest...
Abstract New proxy records from deep‐sea sediment cores the northwestern continental margin of Western Australian reveal a 5.3 million year (Ma) history aridity and tropical monsoon activity in Australia. Following warm dry early Pliocene (~5.3 Ma), continent experienced gradual increase humidity peaking at about 3.8 Ma with higher than present‐day rainfall. Between 2.8 Ma, climate became progressively more arid rainfall variability. Coinciding onset Northern Hemisphere glaciations...
Late Quaternary hemipelagic sediments in the Japan Sea contain aeolian dust from East Asia which potentially records past variations Asian monsoon and westerly jet. However, extracting information about is difficult because also detrital material Japanese Islands. Here we present a method for components using provenance analysis of different size fractions. Hemipelagic can be described by combination two populations characterized lognormal grain distributions with median sizes, are called...
Abstract Three long sediment cores recovered from the SE Pacific were subjected to a comprehensive magnetostratigraphic investigation. According partly preliminary age models obtained, reach 48, 140, and 482 ka back in time, respectively. At two sites (PC02 PC03 at ∼46°S) sedimentation rates are highly variable, ranging about 2 100 cmka −1 , whereas significantly lower southernmost site (PC04, ∼51°S), 1 20 . All three provide evidence for Laschamps geomagnetic excursion 41 ka. However, was...
The Westerly Jet, locating northern boundary of the Hadley Circulation, plays a critical role in contributing mid-latitude climate by facilitating heat and moisture transport through its meandering path. Previous proxy records numerical simulations have shown that Jet’s path was altered response to repeated reduction events Atlantic Meridional Overturning Circulation (AMOC) during Last Glacial period, modulation Cell intensity latitudinal position (e.g. Nagashima et al., 2011; Lee...
During the last glacial period, millennial-scale iceberg discharges in North Atlantic, known as Heinrich Events (HEs), could have shifted Southern Hemisphere Westerly Wind Belt (SWW) poleward and potentially led upwelling-driven CO2 outgassing from Ocean. However, direct evidence of SWW shift response to HEs remains limited. Based on detrital elements, minerals, grain-size records well-dated sediment cores, MR16-09 PC02 (46°04.23′S, 76°32.10′W, 2793 m...
Abstract. Understanding the spatial and temporal variations in mineral dust sources Greenland ice cores during Holocene is challenging due to low concentration. Here, we present first continuous records of size composition, as well potential sources, preserved a northeastern core (EGRIP) covering period from 1910 2013. Using multi-proxy provenance approach based on individual particle analysis, reconstruct ice-core sources. We apply recently developed tracing technique, namely scanning...
Abstract Production, transport and deposition of aeolian dust from land to sea closely interact with regional environment global climate. This Special Issue addresses the Asian inland Loess Plateau North Pacific Ocean their possible links oceanic ecosystem, climate even human activity, over various timescales. The papers in this volume are multidisciplinary nature include sedimentology, mineralogy, geochemistry, environmental magnetism modelling on multi-timescales interannual,...
Abstract– We performed micro‐Raman spectroscopic analyses of the carbon vein in five ureilites: Allan Hills (ALH) A77257, Northwest Africa (NWA) 3140, Shişr 007, Yamato 790981 (Y‐790981), and 791538 (Y‐791538). The graphite peaks showed that structure ureilite is well developed, especially compared with carbonaceous material chondrite. domain sizes were 45–110 Å. observed shifts diamond peak positions to higher wave numbers a large full width at half maximum (FWHM), for NWA 3140. Although...
In the densely populated region of East Asia, it is important to know mechanism, scale, and frequency heavy precipitation brought about during monsoons typhoons. However, observational data, which cover only several decades, are insufficient examine long-term trend extreme its background mechanism. humid areas, transport flux a suspended detrital material through river system known have an empirical power relationship with precipitation. Thus, sedimentation fine could potentially be used as...
Abstract Asian dust has a significant impact on the natural environment. Its variability multiple timescales modulates ocean biogeochemistry and climate. We demonstrate that temporal changes in deposition flux of Aeolian recorded sediments from Lake Suigetsu, central Japan, during last century exhibit continuous decreasing trend decadal‐scale decrease 1952–1974. The former can be explained by storm frequency at source regions due to warming Mongolia twentieth century, suggesting future...