【摘要】 2013年4月20日四川芦山M7.0级地震发生在龙门山断裂带南段,震源机制解为逆冲型.震后3天震区已发生3000多次余震,其中M5级余震4次,最大余震是4月21日17时05分芦山、邛崃交界M5.4级地震,余震区长轴约45km,短轴约20km.芦山M7.0级地震与2008年5月12日汶川M8.0级地震均位于龙门山断裂带,但汶川地震发生在该断裂带中-北段,两个地震的余震区存在约45km的间隔,芦山M7.0级地震不是汶川地震的余震,但两者密切相关.更多还原

【Abstract】 The Lushan,Sichuan M7.0 earthquake on 20 April 2013 occurred on the southern segment of the Longmen Shan fault zone.Its focal mechanism is reverse faulting.Over 3000 aftershocks in 3 days after the mainshock have been recorded,of which 4 events are M5 and the maximal aftershock is the M5.4 shock at 17:05 on 21 April,2013 on the Lushan-Qionglai border.The long axis is about 45 km and the short axis about 20 km of the aftershock area.Both the Lushan M7.0 earthquake and Wenchuan M8.0 earthquake on 12 May,2008 took place on the Longmen Shan fault zone,and the Wenchuan event occurred on the central-northern segments.There is about 45 km-long interval between the two aftershock areas.The Lushan M7.0 earthquake is not an aftershock of the 2008 Wenchuan M8.0 earthquake,though there is a close relationship between the two events.更多还原