2012年2月16日河源M4.8级地震

ML 4.8 Earthquake in Heyuan County on Feb. 16,2012

通过地震序列特征分析初步判断认为,河源ML4.8级地震与库水位变化的对应关系不明显,短期内震中区发生更大地震的可能性很小。现场宏观调查结果显示,极震区Ⅵ度等震线长轴为北北西向,震源机制解所反映的震源应力场主压应力方向为北西西向,与区域构造应力场方向一致;地震的发震构造应为北北西向,但震中区附近并无此组断裂出露地表,因此河源ML4.8级地震的成因,仍然值得深入研究。

In this Paper,it is preliminarily concluded that,based on analysis of the earthquake sequence characteristics,the ML4.8 earthquake in Dongyuan is not clearly correspond to the water level change of Xinfengjiang Reservoir,and there would be slim chance for a larger earthquake in the epicentral area in the short term.It is indicated in the on-site macroseismic survey that,the major axis of the VI isoseismal curve in the meizoseismal area is in the direction of NNW;the principal compressive stress of the seismic source stress field as reflected by the focal mechanism solution is in the direction of NWW,the same direction with the regional tectonic stress field;and the seismogenic structure of this earthquake should be in the direction of NNW,but no surface fault appears around the epicentral area.Therefore,the cause of this earthquake is still worthy of in-depth study.