汶川余震前甘陕交界扰动异常的定源探索  

SEARCHING ON SOURCE OF ABNORMAL DISTURBANCE IN BORDER REGION OF SHAANXI AND GANSU

作　　者：张希[1] 王庆良[1] 贾鹏[1] 

机构地区：[1]中国地震局第二监测中心,陕西西安710054

出　　处：《内陆地震》2013年第1期1-6,共6页Inland Earthquake

基　　金：中国地震局星火计划项目(XH12072);地震行业专项(200808044)资助

摘　　要：2008年8月6日,甘肃武都台、陕西汉中与宁陕台垂直摆倾斜观测获得尖脉冲为主的扰动异常。根据异常出现时间、空间位置等信息,构建"源兆信号"传播函数,借助网格搜索及拟牛顿最小二乘法反演可能的"震源区"。所得模拟震源位于龙门山断裂北段汶川余震区,可能与距其约54 km的2008年8月7日平武—北川5.0级地震有关,传播起始时间为震前近33小时。Abnormal disturbances like sharp pulse were obtained from vertical pendulum in Wudu, Hanzhong and Ningshan station on Aug. 6th ,2008. According to time and space of anomalies, they build ＂source precursor＂ propagator to calculate possible focal region through Newton least square and grid search Method. The calculating focal region located at northern region of Longmenshan fault, is related to Pingwu, Beichuan earthquake with MsS. 0, 54 km away and the starting time is about thirty three hours before the earthquake.

关 键 词：汶川余震 尖脉冲扰动 源兆信号 

分 类 号：P315.725[天文地球—地震学]