利用波速比判定暴雨触发微震震群特例

A case study for determining microseismic swarm triggered by rainstorm with us of wave velocity radio

在严重干旱背景下,2010年6月27日—30日广西西北部出现大暴雨,28日凌云—凤山交界发生3级(ML)震群活动,采用多台法计算主震30 km范围内震群前后及期间2.0级以上地震波速比,并利用单台法计算甲龙、平果地震台波速比,发现震群波速比高于震群发生前后数值,靠近震区的流动台、甲龙地震台波速比高于平果地震台。利用波速比判别震群是否由降水触发,对震情趋势判定有一定参考。

In the context of severe drought, a heavy rain occurred in the northwest of Guangxi from June 27 to June 30, 2010. An M 3 (ML, below) earthquake swarm occurred at the junction of Fengshan and Lingyun. The wave velocity radio of the earthquake swarm, include all of the earthquakes with magnitude 2.0 or more and in the range of 30 km around, before and during, the maishock was calculated with multiple-station method. And the single-station method was used to calculate the wave velocity ratio of Jialong and Pingguo seismic station. It is found that the wave velocity ratio of earthquake swarm is higher than that of before and after the earthquake swarm. The wave velocity of the mobile stations and Jialong Seismic Station, which are nearer the earthquake, is higher than that of Pingguo Seismic Station. Using the wave velocity ratio to determine whether the earthquake swarm is triggered by the precipitation has certain reference significance for seismicity trend determining.