JOPSS - Search Results

Watanabe, Takahiro; Nara, Fumiko*; Matsunaka, Tetsuya*; Minoura, Koji*; Kakegawa, Takeshi*; Yamasaki, Shinichi*; Tsuchiya, Noriyoshi*; Nakamura, Toshio*; Junbo, W.*; Liping, Z.*

no journal, ,

Understanding of past environmental and geochemical changes is significant issues to estimate global climate variation. Therefore, these changes have been studied by continuous terrestrial sediments. The high-time resolution past environmental changes, especially monsoon fluctuations, have been reported in previous studies using geochemical signatures in stalagmites from Asian caves. However, continuous climate records in Tibetan plateau have not yet been cleared, which a key area to understand mechanism of monsoon fluctuations. In this study, mean grain size and geochemical proxies from lake sediment cores from south Tibetan plateau were used for estimation of past monsoon changes during Holocene. Spectral analysis of the mean grain size in the Tibetan lake indicated 1000-1500 years climate cycles, which might be caused by the changes in solar activities. These monsoon fluctuations based on the mean grain size were also supported by geochemical proxies in this study.

Oral presentation

Rb/Sr ratio in Lake Baikal sediment core; The New geochemical proxy for East Asian winter monsoon strength during cool climate period

Nara, Fumiko*; Yamasaki, Shinichi*; Watanabe, Takahiro; Tsuchiya, Noriyoshi*; Miyahara, Hiroko*; Kato, Takenori*; Minoura, Koji*; Kakegawa, Takeshi*

no journal, ,

High-time resolution measurements of the major and trace inorganic elements, such as Rb and Sr, from the Lake Baikal sediment core was carried out to estimate the weathering response and the material provenance in the lake watershed. The fluctuations of the Rb/Sr ratio and mean grain size (MGS) during the Holocene were corresponding with each other. The similar profiles between the Rb/Sr ratio and the MGS from loess sediment in China have been observed in previous study. These results imply that the Rb/Sr ratio can be used as the proxy to estimate the East Asian winter monsoon intensity.

Oral presentation

Geochemical-fluid analysis for the natural purification mechanism of arsenic and iron in Ningyo-toge mill tailings pond

Kawasaki, Yohei*; Yagisawa, Makoto*; Granata, G.*; Tokoro, Chiharu*; Ohara, Yoshiyuki

no journal, ,

no abstracts in English

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The Aqueous solubility and speciation analysis for uranium, neptunium and selenium by the geochemical code (EQ3/6)

Geochemical studies for geologic disposal of high-level radioactive waste; Research activities in Department of Environmental Safety Research, Japan Atomic Energy Research Institute

Sensitivity analysis of geologic disposal of high-level radioactive waste for conceptual geologic media

Quantitative performance allocation of multi-barrier system for high-level radioactive waste disposal

Safety and sensitivity analyses of a generic geologic disposal system for high-level radioactive waste

Chemical behavior of neptunium in groundwater

Mechanistic,Kinetic and thermodynamic study of uranium fixation by natural organic matter-a trial of organometallic geochemistry-

The Millennium scale monsoon cycles recorded in a sediment core from alpine Tibetan lake

Rb/Sr ratio in Lake Baikal sediment core; The New geochemical proxy for East Asian winter monsoon strength during cool climate period

Geochemical-fluid analysis for the natural purification mechanism of arsenic and iron in Ningyo-toge mill tailings pond