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

Effects of warming daring a glacial-interglacial transition on the palaeogeography and macro aural assemblages on continental shelf in the Sea of Japan

冰川-间冰期转变期间的变暖对日本海大陆架古地理和宏观听觉组合的影响

基本信息

批准号：
08454150
负责人：
KITAMURA Akihisa
金额：
$ 4.54万
依托单位：
Shizuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08454150/
关键词：
glacial period interglacial period warming Sea of Japan continental shelf macrofaunal assemblages planktonic foraminifera

项目摘要

Global warming resulting from the increase of the greenhouse gases is one of the very serious problems. The effects of warming on the oceanography and macrofaunal assemblages have not yet examined on continental shelf in the Sea of Japan. Thus, we studied the stratigraphic distribution and abundance of both benthic molluscs and planktonic foraminifera from a particular horizon in the early Pleistocene Omma Formation. A particular horizon corresponds shelf sediment during the deposition at the initiation of flow of the warm Tsushima Current. We used planktonic foraminifera as indicator of the Tsushima Current, because they have short generation times and have responded rapidly relative to environmental changes rather than adult molluscs, which may lag behind changes.The result indicates that local extinction of cold-water molluscs lagged behind about 2,300-2,400 years after the initiation of the intrusion of the Tsushima Current. Then migration of a warm-water molluscan fauna to the shelf occurred shortly after the local extinction of cold-water molluscs. These lead to the following conclusions :1) the rate of increase in thickness of the Tsushima Current during the initiation of flow was faster than that of the sea-level rise ;2) the most important factor causing local extinction of them was probably the rise in temperature ; and3) an environment during local extinction of cold-water molluscs and appearance of warm-water molluscs may be unsuitable for both them. Perhaps such environment may be caused by the establishment of a climatic phase of high seasonality.There is a possibility that future warming will produce such condition on the continental shelf around Hokkaido which is southern limit of cold-water molluscs.

温室气体的增加导致的全球变暖是非常严重的问题之一。气候变暖对海洋学和大型底栖动物组合的影响尚未在日本海的大陆架上进行研究。因此，我们研究了早更新世Omma组特定层位的底栖软体动物和浮游有孔虫的地层分布和丰度。一个特定的地平线对应的陆架沉积物在沉积过程中的流动的温暖的对马电流的开始。我们选择了世代时间短、对环境变化响应快的浮游有孔虫作为对马海流的指示生物，而不是滞后于环境变化的成年软体动物，结果表明冷水性软体动物的局部灭绝滞后于对马海流入侵后约2,300-2,400年。然后，在冷水软体动物局部灭绝后不久，暖水软体动物群迁移到大陆架。由此得出以下结论：1）对马海流在开始流动时厚度的增加速度快于海平面的上升速度;2）温度的升高可能是导致它们局部灭绝的最重要因素; 3）冷水性软体动物局部灭绝和暖水性软体动物出现的环境可能不适合它们。这样的环境可能是由于季节性强的气候阶段的形成造成的。未来的变暖可能会在冷水软体动物的南部界限北海道周围的大陆架上产生这种情况。