Study on the ice sheet dynamics and its environmental changes of the East Antarctica

本项目旨在系统地研究东南极洲瑞穗高原冰盖动力学和过去气候变化的综合跨学科领域和实验室研究工作。该项目的三个主要目标是分析700米深的瑞穗冰芯，绘制冰盖的厚度和地下地形，测量冰盖的表面速度。得到的结果如下：1。Mizuho冰芯的氧-18分析表明，在150m以上，^<18>浓度随深度的减小而增加。这一事实表明冰盖表面正在下降。冰芯的微粒分析结果表明，几千年前发生了一次大的环境变化。无线电回波探测显示，在瑞穗高原的大部分地区，基岩上的冰正在融化。卫星导航系统观测到瑞穗高原下游地区冰盖以1 m/a的速度变薄。这些事实表明，东南极洲瑞穗高原由于冰盖基底滑动而处于灾难性前进的不稳定状态，并且冰盖基底滑动延伸到白濑冰川流域下游的整个地区。

This project was designed as a comprehensive interdisciplinary field and laboratory research effort to systematically investigate the ice sheet dynamics and past climatic changes of the Mizuho Plateau, East Antarctica. Three of the major goals of this project were analysing a 700m deep Mizuho ice core, mapping the thickness and he subsurface topography of the ice sheet and measuring the surface velocity of the ice sheet. The results obtained are as follows.1. Oxygen-18 analyses of the Mizuho ice core reveal that ^<18>o concentration increases with decreasing depth above 150m depth. This fact suggests the lowering of the ice sheets surface.2.The results of microparticle analysis of ice core suggest that there was a big environmental change several thousands years ago.3. The radio echo sounding survey shows that the ice is melting on the bedrock at the large part of the Mizuho Plateau.4. The thinning of ice sheet at the rate of 1 m/a was observed over the down stream area of the Mizuho Plateau by the satellite navigation system.These facts suggest that the Mizuho Plateau, East Antarctica is in unstable condition of catastrophic advance due to basal sliding of ice sheet and the basal sliding of the ice sheet extends to the whole area down stream the Shirase Glacier drainage basin.