Preliminary analysis of strong motion characteristics of the Maerkang earthquake swarm in Sichuan on June 10，2022

On June 10, 2022, an earthquake swarm consisting of M_S5.8, M_S4.1, M_S4.4, M_S6.0, and M_S5.2 earthquakes occurred in Maerkang, Sichuan, China. This study filtered and analyzed the strong-motion records, conducted time-frequency analysis on acceleration data, and compared energy distributions among these earthquakes. By referencing the Fifth Generation Seismic Zoning Map, the attenuation relationships of peak ground acceleration （PGA）, peak ground velocity （PGV）, and spectral acceleration （SA） were analyzed. The acceleration and velocity response spectra, as well as Fourier amplitude spectra, were calculated and compared. Results indicate similar energy distribution patterns, with the attenuation model in the Fifth Generation Seismic Zoning Map predicting PGA, PGV, and SA （0.2） well of M_S＞5.0 earthquakes but overestimating SA （0.5） and SA （1.0）. Response spectrum shapes and peak periods were identical at the same station, with values not exceeding local seismic design specifications. Normalized response spectra highly coincided for T＜0.2 s in M_S＞5.0 earthquakes. Horizontal Fourier spectra were similar, with main frequencies in the 10−20 Hz range. Strong correlations were observed among acceleration and Fourier spectra in the same direction at the same station for all five earthquakes.