澜沧—耿马大震前后尾波Q值的研究

本文根据Aki的尾波散射理论,对澜沧-耿马大震前后近10年的时间,在大震区域及外围的7个地震台近2000多张地震记录图的尾波进行测量,得出Q值随时间变化的结果表明:澜沧、耿马两次大震前有1～3年左右的低Q值异常期;在临近大震前1年左右,Q值处于回升阶段;震后Q值明显增大.并结合澜沧-耿马地区区域地质构造图,试图分析Q值在断层错动中随时间变化的特征;澜沧、耿马7.6、7.2级两次大震是分别孕育的双主震并且可能是澜沧7.6级大震的发生触发了耿马7.2级大震的发生。

The Resarch of the in Coda Q Around Lancang Gengma Great Earthquakes

The coda waves of more then two thousands seismic recored maps were measured by using the theory of Aki's coda waves sattering . Those maps were derived from seven seismic stations of the region of the Lancang-Gengma great earthquakes and the periphery of it, It's nearly ten years around Lancang-Gengma great earthquakes. The result by analysising the Q variations with time shows: There was abnormal period of low Q about one to three years bebfor the Lancang-Gengma graet earthquakes; The Q rised again befor occurring great earthaqakes about one year; The Q were then the Q was increase clearly after the great earthquakes. The characteristics of the Q variations with time in the fault crossing were described combining the map of active regional stress field of geolgical structure in the area, It's only trg. twin main-quake type of MS7.6 Lancang and MS7.2 Gengma great earthquakes were peagnant respectively, and the occurrence of the MS7.2 Gengma great earthquake was triggered by the MS7.6 lancang graet earthquake.