A new estimate of the Holocene lowstand level of Lake Titicaca, central Andes, and implications for tropical palaeohydrology
A new estimate of the Holocene lowstand level of Lake Titicaca, central Andes, and implications for tropical palaeohydrology
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DOI：
10.1191/095968300671452546
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发表时间：
2000-01-01
期刊：
影响因子：
2.4
通讯作者：
Dunbar, RB
中科院分区：
文献类型：
--
作者：
Cross, SL;Baker, PA;Dunbar, RB
来自活塞岩心和高分辨率地震反射数据的新证据表明，的的喀喀湖的水位在全新世早期至中期（>6至3.8 C-14 kyr BP之间）比现在的水位低100米。气候学和模拟研究表明，的的喀喀湖的降雨取决于逆风亚马逊河流域的对流活动;因此，湖面数据表明，在此期间亚马逊河流域更干燥。的的喀喀湖水位曲线与格陵兰冰层中甲烷浓度下降之间的出色匹配支持了这一观点，此前格陵兰冰层中甲烷浓度下降归因于低纬度湿地的干燥（Blunier et nl.，1995年）。的的喀喀湖的冰后期历史符合热带地区湖平面变化的全球模式，其特征是南半球和北方半球之间的相位相反。这种模式很可能是轨道控制夏季日照强度的结果。
New evidence from piston cores and high-resolution seismic reflection data shows that water levels in Lake Titicaca were as much as 100 m below the present level during the early to mid-Holocene (between >6 and 3.8 C-14 kyr BP). Climatological and modelling studies indicate that Lake Titicaca rainfall depends on convective activity in upwind Amazonia; the lake-level data therefore suggest a drier Amazon Basin during this time. This view is bolstered by an excellent match between the Titicaca lake-level curve and decreased methane concentrations in Greenland ice, previously ascribed to drying of low-latitude wetlands (Blunier et nl., 1995). The postglacial history of Lake Titicaca fits a global pattern of lake-level change in the tropics, characterized by opposite phasing between the Southern and Northern Hemispheres. This pattern is most likely the result of orbital controls over the intensity of summer insolation.