2019年北京海淀M2.9和怀柔M3.0地震震源参数测定

本文介绍了2019年4月7日北京海淀M2.9及4月14日北京怀柔M3.0地震的基本参数速报情况，并利用区域台网波形数据，采用全波形反演方法ISOLA获得了这两次地震的最佳双力偶解。反演结果显示:M2.9地震的节面Ⅰ走向29°，倾角70°，滑动角?149°，节面Ⅱ走向288°，倾角61°，滑动角?22°；矩心深度14 km，矩震级M_W=3.4。M3.0地震的节面Ⅰ走向93°，倾角84°，滑动角?30°，节面Ⅱ走向186°，倾角60°，滑动角173°；矩心深度16 km，矩震级M_W=3.4。震源机制反演结果表明，两次地震均为走滑型为主的地震，其与震源区域附近历史地震震源机制解具有相同性质。 

Determination of the source parameters of the Haidian M2.9 andthe Huairou M3.0 earthquakes in Beijing in 2019

The parameters of the April 7, 2019 Haidian M2.9 and the April 14, 2019 Huairou M3.0 earthquakes in Beijing are rapidly determined by the CENC. The best double-couple solutions of the two earthquakes in Beijing are studied by the ISOLA full-waveform method using the observed waveform data from the regional seismic networks. The result of this study shows: for the M2.9 earthquake: strike=29°, dip=70° and rake=-149° for nodal plane I, and strike=288°, dip=61° and rake=-22° for nodal plane II. The centroid depth is about 14 km and the moment magnitude （M_W） is 3.4; And for the M3.0 earthquake: strike=93°, dip=84° and rake=-30° for nodal plane I, and strike=186°, dip=60° and rake=173° for nodal plane II; the centroid depth is about 16 km and the moment magnitude （M_W） is 3.4. The focal mechanism inversion shows that these 2 earthquakes are both strike-slip events, which are of the same type as the historical quakes in the adjacent area.