权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Eolian dust deposition and paleo-environmental changes in East Asia since the last Interglacial period

末次间冰期以来东亚风沙沉积与古环境变化

基本信息

批准号：
11680095
负责人：
NARUSE Toshiro
金额：
$ 1.34万
依托单位：
Hyogo University of Teacher Education
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11680095/
关键词：
eolian dust East Asia last Interglacial period last glacial period climatic change monsoon change loess ESR analysis

项目摘要

I collected the four drilling cores of peat deposited since the last Interglacial period from Nayoro basin in Hokkaido, Yanohara moor in Fukushima Prefecture, Nakaikemi baisin in Fukui Prefecture and Kuroi basin in Hyogo Prefecture in Japan. In addition to those areas, I collected two drilling cores of peat and clay deposited since the last glacial period from Tanigumi moor in Gifu Prefecture and Cheju Island in Korea. Six cores show following climatic features as inferred from eolian dust analysis: climatic changes, wind direction, and the location of polar front in East Asia since the last Interglacial period.Summer monsoon was predominantly and fluvial material deposited in the basins and moor by the increased summer rain during MIS 5 and MIS 1. As the polar front shifted to the North Hokkaido, eolian dust was transported from the inland desert areas in China by westerlies. In the last glacial period, the polar front migrated to the Seto Inland Sea. Eolian dust was transported from the Precambrian rock areas and the emerged sea floor by the NW winter monsoon between Hokkaido and the Seto Inland Sea. In Interstadials 24 to 1 during the last glacial period, fluvial material deposited. On the other hand, eolian dust deposition increased in the cold periods such as Heinrich events. The median diameter of eolian dust fluctuated with a saw-tooth shape provoked by the gradual glaciation and abrupt deglaciation during the last glacial period. After 14 ka, eolian dust deposition decreased, and median diameter of fluvial material increased. Obtained pattern is in agreement with the general correspondence between dust deposition and climatic changes. Eolian dust record from six cores showed trends also seen in dust records from polar regions.

笔者从日本北海道的纳约罗盆地、福岛县的矢野原摩尔、福井县的中凯米白心和兵库县的黑井盆地采集了末次间冰期以来沉积的四个泥炭钻孔岩心。除此之外，我还从岐阜县谷组摩尔沼泽和韩国济州岛收集了两个自末次冰期以来沉积的泥炭和粘土钻孔岩心。6个柱状样的风成尘分析表明，末次间冰期以来东亚地区的气候变化、风向和极锋位置等气候特征，MIS5和MIS1期间夏季降水增多，夏季风占主导地位，河流物质沉积在盆地和摩尔沼泽中。随着极锋向北移到北海道，西风带将沙尘从中国内陆沙漠地区输送过来。末次冰期，极锋向濑户内海迁移。在北海道和濑户内海之间的西北冬季风的作用下，风成尘从前寒武纪岩石区和露出的海底输送过来。在末次冰期的第24至第1个间冰期，河流物质沉积。另一方面，在寒冷时期，如Heinrich事件，风尘沉积增加。末次冰期的逐渐冰川作用和突然冰消作用使风尘中值粒径呈锯齿状波动。14 ka后，风尘沉积减少，河流物质的中值直径增加。所得到的模式符合沙尘沉降与气候变化的一般对应关系。来自六个岩芯的风尘记录显示了极地地区的沙尘记录也出现了这种趋势。