2012年加拿大西海岸M_W7.7地震构造背景与区域地震活动  

Tectonic context and activities of historical earthquake in the area of the 2012 M_W7.7 earthquake,western coast of Canada

作　　者：周娜[1] 任俊杰[2] 

机构地区：[1]中国地震台网中心,北京100045 [2]中国地震局地壳应力研究所,北京100085

出　　处：《国际地震动态》2013年第7期28-34,共7页Recent Developments in World Seismology

基　　金：中国地震台网中心青年基金项目资助

摘　　要：2012年10月28日加拿大西海岸发生了MW7.7地震,震中位于板块边界的夏洛特皇后断裂南段,处于环太平洋地震带上,是太平洋板块相对北美板块以约6cm/a的速率,使得断层面应变积累到一定程度引发破裂的结果。历史地震分析表明,该地震正好填充了南段一个多世纪以来存在的空区。该地震的发生可能表明一个新的地震周期的开始,未来几十年内该断裂带上可能以中强地震活动为主,发生8级左右地震的可能性不大。The 2012Canada earthquake(MW7.7)occurred on the southern segment of the Queen Charlotte fault,which lies on the Circum-Pacific seismic belt and separates the Pacific plate from the Northern American plate.The motion of the Pacific plate with a rate of ～6cm/a along the Queen Charlotte fault with respect to the Northern American plate generated the accumulation and release of strain on the fault plane to a critical level and finally ruptured during the 2012 MW7.7earthquake.The occurrence of the 2012earthquake filled the seismic gap found in previous studies on the rupture of historical earthquakes.This earthquake may indicate the starting of a new seismic cycle.In the coming decades,intermediate-strong earthquakes may dominate and there is a low level of possibility for an earthquake with magnitude～8.

关 键 词：夏洛特皇后断裂 太平洋板块 北美板块 Cascadia俯冲带 

分 类 号：P315.5[天文地球—地震学]