中国西南50-15万年来石笋记录的气候事件及全球意义

50-15 万年 石笋记录 高分辨率 时标序列 中国西南
张美良 2008-01 项目
【英文摘要】In the field of globe change, the formation and evolution of Asia monsoon is animportant scientific forward problem to which has been paid extensive attention andstill not resolved ultimately.In recent years, Chinese scientists have made notableprogress on Asia palaeo- monsoon by studing Ocean cores and lakes, loess, ice core, andso on, and has in the front ranks of the World. Because of lacking researches oncorrsponding sediments in the southwest of China, making use of cave stalagmites tostudy the reglarity of climatic evolution from 500ka BP to 150ka BP in the Southwest ofChina is of great improtance in understanding global change and forecasting climatechange in the future. By high precision ICP-MS-U/Th or TIMS-U series dating, highresolution records of the oxygen and carbon isotopes and trace elements from cavestalagmites, the project will study the regularity of climatic change in the tenmillennial, millennial and centennial timescale from 500ka BP to 150ka BP in southwestof China, catch climatic abrupt events, and study their phase, cyclicity, amplitude,behave characters, and so on.These events will be compared with the previous records ofglobal abrupt events and reveal the history of monsoon evolution and difference on Asiamonsoon. The target of the project is to establish a standard time-scale series ofclimatic change from 500ka BP to 150ka BP in southwest of China and discuss theirresponse to the global changes and its mechanisms, and provide scientific basis for theglobal change reference and forecasting climate change in the future.
【中文摘要】亚洲季风形成和演化是全球变化领域广泛关注而且仍未根本解决的重大前沿科学问题。近几十年来,我国科学家利用海洋和湖泊沉积、黄土、冰芯等研究亚洲古季风己取得了引人注目的成果,并进入国际领先行列。由于西南地区缺乏相应沉积物的系统研究,所以,利用岩溶地区的洞穴石笋,研究西南地区50-15万年以来的气候变化规律,对于认识全球变化和预测未来气候变化具有重要意义。本项申请,通过对洞穴石笋的高精度MC-ICP-MS铀系定年,高分辨的碳、氧同位素、微量元素分析,研究50-15万年(即中更新世中期)以来的万年、千年、百年时间尺度的气候变化规律, 捕捉气候突变事件,重大事件发生的相位、周期、变幅、表现特征等,并与已有的全球突发事件记录进行对比,揭示季风的演变历史及其差异性。最终建立50-15万年来的标准时标序列,探讨其与全球变化的响应关系及其机理,为全球变化对比和预测未来气候变化提供科学依据。