摘要
依据天山7个有确切年代学资料的典型地区进行冰川面积和平衡线高度等重建,揭示天山地区末次冰期以来冰川经历的扩张和收缩过程。冰川规模在MIS 4~MIS 3大幅度扩张,形成大规模的复合型山谷冰川和山麓冰川;MIS 2冰川扩张显著,但远不及MIS 4~MIS 3,许多山区形成大型山谷冰川;全新世新冰期NG和小冰期LIA都略有扩张,冰碛垄分布在现代冰川外围,冰川类型与现在一致。冰川平衡线高度的降幅亦表现为MIS 4~MIS 3最大,MIS 2以后降幅递减。MIS 4~MIS 3天山冰川大规模扩张与欧亚冰盖演化,巨大冰前湖泊、广阔的湿地的形成为西风提供更多水气带到天山有关;MIS 2至今,随着欧亚冰盖减小到消失,西风带来的水气渐少,干冷的蒙古高压逐渐加强,制约了冰川规模扩张。
Based on the reconstruction of paleo-glaciations and estimation of paleo-ELAs of seven study areas with precise chronological data,in this paper,the advance and recession of the glaciers in the Tianshan Maintains since the Last Glacial were revealed. Marine Isotope Stage（MIS） 4 and MIS 3 were significant periods of glacial advance with large-scale,forming compound valley glaciers and piedmont glaciers; during MIS 2,glaciers（mainly valley glaciers） still expanded significantly,but far less than before. In Neoglaciation（NG） and Little Ice Age（LIA） there were slight expansion of glaciation,showing their terminal moraines had distributed in front of contemporary glaciers and the glacier types were the same as present. The decreasing amplitude of ELA had shown a parallel pattern： with a maxima decline during MIS 4 and MIS 3,and a progressively diminishing decline since MIS 2. The great glacial expansions in MIS 4 and MIS 3 in the Tianshan Mountains were related to more moisture being transported into by the westerlies from ice-dammed lakes and wet lands formed by the Eurasian Ice Sheets. Since MIS 2,the recession of Eurasian Ice Sheets,the decrease in moisture from westerlies and the gradually strengthening Mongolian High may have resulted to glacier shrinkage.
作者
肖菁
刘耕年
聂振宇
陈艺鑫
彭旭
刘蓓蓓
韩业松
崔之久
XIAO Jing;LIU Gengnian;NIE Zhenyu;HAN Yesong;CHEN Yixin;PENG Xu;LIU Beibei;CUI Zhijiu(College of Urban and Environmental Sciences,Peking University,Beijing 100871,China)
出处
《冰川冻土》
CSCD
北大核心
2018年第3期434-447,共14页
Journal of Glaciology and Geocryology
基金
国家自然科学基金项目(41371082
40971002
41230743)资助
关键词
天山
末次冰期
冰川物质平衡线
古气候变化
Tianshan Mountains
Last Glacial
equilibrium line
paleoclimatic variation
