Lake Qinghai Scientific Drilling Project
Lake Qinghai Scientific Drilling Project
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DOI：
10.2204/iodp.sd.2.05.2006
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发表时间：
2006-03
影响因子：
1.2
通讯作者：
A. Zhisheng;A. Li;S. Yougui;S. Colman
中科院分区：
文献类型：
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作者：
A. Zhisheng;A. Li;S. Yougui;S. Colman
位于青藏高原东北缘，海拔3194米(图1)。该湖对气候变化极其敏感，因为它位于东亚季风控制的湿润气候区和受西风影响的干燥内陆地区之间的关键过渡地带。三个主要的大气环流系统影响其气候：(1)由西伯利亚高压和相关的高纬度冰盖引起的冬季季风；(2)由东亚夏季风携带的来自低纬度的热带湿气；(3)北大西洋地区的气候变化，其影响被推断为通过西风带传播。对青海湖及其周围地区钻探岩心的研究对于了解该地区的气候、生态和构造演化，包括东亚季风系统的发展及其与全球主要大气环流的关系至关重要。青海湖位于一个主要的活动逆冲断层的上盘，占据着一个封闭的构造凹陷，或称背靠式盆地。盆地的北面是祁连山，祁连山构成了青藏高原的东北边缘。因此，湖盆与青藏高原的活动构造密切相关。地震反射资料表明，湖相沉积在盆地的某些部分发生了构造变形，而在其他部分基本未发生变形，这至少应该记录了区域构造活动的时间。地震勘探表明，浅水湖盆下覆有南北两个次级盆地，南部次级盆地含有厚度超过700m的连续松散沉积层序。2003年10月，在中华人民共和国中国西宁举行的一次国际研讨会上，青海钻井项目计划从至少四个不同的地点获取一系列岩心，穿透200-700米进入湖泊沉积物，并可能到达上新世或更老的地层。其他具有5-50米浅穿透深度的地点计划瞄准全新世和持续几个冰川周期的特定高分辨率气候间隔。该项目的总体科学目标如下所示。
on the northeastern margin of the Tibetan Plateau at an elevation of 3194 m (Fig.1). The lake is extremely sensitive to changes in climate because it lies in a critical transitional zone between the humid climate region controlled by the East Asian monsoon and the dry inland region affected by westerly winds. Three major atmospheric circulation systems affect its climate: (i) the winter monsoon, induced by Siberian high pressure and associated high-latitude ice cover; (ii) tropical moisture from low latitudes, carried by the East Asian summer monsoon; and (iii) climatic changes in the North Atlantic region, the effects of which are inferred to be transmitted via the westerlies. A study of drill cores from the lake and the surrounding area is critical for understanding the climatic, ecological, and tectonic evolution of the area, including the development of the East Asian monsoon system and its relationship to major global atmospheric circulation.Lake Qinghai occupies a closed tectonic depression, or piggy-back basin, on the upper plate of a major, active thrust fault. The basin is bound to the north by the Qilian Mountains, which constitute the northeastern margin of the Tibetan Plateau. The lake basin thus is intimately related to the active tectonics of the Tibetan Plateau. Seismic-reflection data show that the lake sediments are tectonically deformed in some parts of the basin and largely undeformed in other parts, where they should record at least the timing of regional tectonism. The seismic surveys indicate that the shallow lake is underlain by northern and southern sub-basins and that the southern sub-basin contains a continuous strati-graphic sequence of unconsolidated sediments more than 700 m thick. At an international workshop in Xining, People’s Republic of China in October 2003, the Qinghai Drilling Project was planned to obtain a series of cores from at least four different sites, penetrating 200–700 m into the lake sediment and possibly reaching Pliocene or older strata. Other sites with shallower penetrations of 5–50 m were planned to target specific high-resolution climatic intervals in the Holocene and last several glacial cycles. The overall scientific objec-tives of the project are listed below.