Abstract:Using the method of the maximum amplitude ratio between P and S to inverse the focal mechanisms of small and medium earthquakes, and by using the digital waveform data of the small and medium earthquake occurred in the central and western Inner Mongolia from 2001 to 2008, 130 focal mechanisms were obtained. The results show that there are two groups of nodal plane in NWW-SEE and NESW. From the effect of the compressive stress in NEE-SWW direction and the tensile stress in NNWSSE direction, the NWW-SEE break side results in the right sliding, the NNW-SSE one in the left sliding. Systemic clustering analysis shows that small and medium earthquakes in the central and western Inner Mongolia were mostly with the section of vertical surface and strikeslip focal mechanism solution. By contrasting the focal mechanism of Hangjinqi and Tuoketuo Ms4 earthquakes with the background field, it is found that both of them are not precursor earthquakes. Through the analysis of consistency focal mechanism of parameters, there is a low value area of focal mechanism parameters in the central and western Inner Mongolia,it may have a certain significance to earthquake prediction.
Liu Fang ,Wang Xiaoshan ,and Yang Yaqiong . FOCAL MECHANISM ANALYSIS OF SMALL EARTHQUAKEIN CENTRAL AND WESTERN INNER MONGOLIA[J]. jgg, 2010, 30(Supp.1): 7-11.