汶川8.0级地震前定点形变异常特征  

Characteristics of deformation anomaly obtained from tilt and strain observations before the Wenchuan M_S8.0 earthquake

作　　者：张燕[1] 吴云[1] 吕品姬[1] 

机构地区：[1]中国地震局地震研究所,中国武汉430071

出　　处：《地震学报》2009年第2期152-159,共8页Acta Seismologica Sinica

基　　金："十一五"国家科技支撑重点项目(2006BAC01B02-02);地球空间环境与大地测量教育部重点实验室开放基金项目(08-01-05);地震科学联合基金(A07032);中国地震局地震研究所所长基金(IS200726017)资助

摘　　要：对汶川8.0级地震震中周围800km范围内近50个定点形变台站资料作小波变换处理,发现从震前3个月开始,30个台站资料处理结果显示有异常出现.距震中200km以内的台站,其异常信息主要集中在小波分解的细节部分第6层;距震中200—550km范围内的台站,其异常主要集中在第7层或第8层;距震中550—650km范围内的台站,其异常主要集中在第8层或第9层.表明异常信息的频率随着各台站距离震中的远近呈现由低到高的特征.Applying wavelet transformation to processing observation data of nearly 50 permanent deformation stations, with the epicentral distance less than 800 km to epicenter of Wenehuan Ms8.0 earthquake, that the abnormal signals appeared 3 months before the Wenchuan earthquake in the observation data of 30 stations. In terms of the wavelet analysis, the anomalies mainly appeared on the sixth level at the stations within 200 km from the earthquake, on the seventh or eighth level at stations between 200 km to 550 km , and on the eighth or ninth level of detailed part when stations are in the range of 550 km to 650 km from the epicenter. That is to say, the nearer the stations are from the earthquake epicenter, the higher the frequency of anomalies.

关 键 词：汶川地震 定点形变 小波变换 频率 异常 

分 类 号：P315.725[天文地球—地震学]