摘要
本文在简述东昆仑活动断裂带的构造背景与演化历史的基础上,重点叙述了该活动断裂带的展布、几何结构、第四纪运动和强震活动等特征。指出,这是一条具有长期演化历史、深部构造背景和第四纪乃至全新世强烈活动的断裂带,因而在我国大地构造演化,尤其在青藏高原隆起形成过程中,占有重要地位。同时,它还是我国西部地区一条主要的强震活动构造带,根据现代强震活动记录和在全带新发现的多期全新世古地震及其地表破裂带,分析了大震在断裂带上的空间、时间分布规律。最后,对1937年花石峡7(1/2)级地震的宏观震中位置和所造成的地表破裂带展布、规模等进行了讨论。
Eastern Kunlun active fault zone is one of important large fault in the northern Tibet plateau. The fault zone consists of six secondary faults and shows a pattern of left-steping plume structure. Among secondary faults, it forms three pull-apart basins the Xiugou basin, the Alaghu lake basin and the Tuosuohu lake basin. Eastern Kunlun fault zone has showed intence left-lateral strike-slip movement since mid-Pleistocene. From late-Pleistocene, its average slip-rate is 6-7mm/a, western segment is 12-14mm/a, and it is smaller towards east. Many paleoearthquakes occurred along the fault zone in Holocene, and it formed a series of surface ruptures preserved well. Calculated recurrence interval of large earthquakes is 2000 years. Field studies indicate that the 1937 Huashixiaearthquake M71/2 formed a surface rupture which length was 180km, most level displace-ment was 7m, and the macroscopic epicenter located at eastern coast of the Tuosuohu lake.
出处
《中国地震》
CSCD
北大核心
1996年第2期119-126,共8页
Earthquake Research in China
关键词
青藏高原
活动断裂
地震构造
古地震
地震活动性
Tibet plateau, Active fault, Seismotectonics, Seismic activity, Paleoearthquake
