Abstract:
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 (
MW) 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 (
MW) 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.