2009年3月19日Mw7.6级汤加大地震的“震前扰动”现象

汶川大地震爆发后，作者在武汉大地测量国家野外科学观测站的重力仪资料中发现了震前约48小时的“重力扰动”现象、并在随后对全国数十个台站宽带地震仪资料的分析中得到了证实.2009年3月19日，太平洋岛国汤加海域爆发了M_w7.6级（里氏7.9级）大地震，宽带地震仪资料中再次出现了显著的、信号周期为4~8秒的“震前扰动”现象：从大地震前约16天的3月4日开始一直持续到地震发生.

Observation of fore-seismic disturbance of the Mw7.6 Tonga earthquake (2009/03/19)

It has beenreported that we discovered significant gravity disturbance before the 2008 Wenchuan earthquake (M_s=8. 0) at the Wuhan national field scientific observational station for geodesy , and we confirmed our observation by broadband seismometers data from several tens station across the country. On 19 Mar, 2009 the M_w7.6 earthquake struck the South Pacific island country of Tonga. We found that the significant fore-seismic disturbance was also be observed by broadband seismometers. The disturbance signals started on 16 Mar, 16 days before the Tonga earthquake, with its period mainly in band of 4~8 s.