湖北秭归罗圈荒微震群的成因及其类型鉴别*

(中国地震局地震研究所,武汉 430071)

地震成因; 微震群; 地震波谱; 地震类型鉴别; 湖北

Genesis and Type Identification of Luoquanhuang Microquake Swarm in Zigui, Hubei
ZHANG Li-fen, YAO Yun-sheng, WU Hai-bo, WANG Dun, SHEN Xue-lin

(Institute of Seismology, CEA, Wuhan 430071, Hubei, China)

earthquake origin; microquake swarm; seismic wave spectrum; identification of earthquake type; Hubei

备注

2007年9月22日至10月18日在湖北秭归罗圈荒地区发生了一次微震群活动,其中最大为10月7日的ML2.9地震。震群的宏观震中位于郭家坝镇黄泥滩一带,极震区较小、地震波衰减较快,反映出该微震群的浅源特点。对该区及附近的天然地震和水库地震的波形、波谱特征以及拐角频率等进行对比分析,发现罗圈荒微震群与天然地震及水库地震有较明显差异,综合判定该微震群为矿震。

During Sep. 22 to Oct. 18, 2007, a microquake swarm occurred in Luoquanhuang, Zigui, Hubei(the maximum magnitude is ML2.9 on Oct. 7). The macroscopic epicenters distribute along Huangnitan, the meizoseismal area is small and the seismic wave attenuates fast, which reflects the sources are shallow. We compared the seismic waveform, spectrum characteristics and corner frequency of the Luoquanhuang microquake swarm with those of the natural earthquakes and reservoir-induced earthquakes around the area, and found that they are different obviously. Synthesizing the macro-investigation and seismological analysis, we think the swarm should be in mining-earthquake.