利用区域宽频地震数据反演2021年5月云南漾濞M_(S)6.4地震震源破裂过程

Rupture process of Yunnan Yangbi M_(S)6.4 earthquake constrained by regional broadband seismograms

本文基于有限断层模型反演方法,利用区域宽频带数据反演了2021年5月云南漾濞M_(S)6.4地震的震源破裂过程,结果显示:此次地震的发震断层走向为SE向,主要以右旋走滑为主.破裂主要发生在震源东南侧,最大错动量约为0.55 m,位于深度约9 km处,发生明显破裂的深度约达13 km.此次地震释放的标量地震矩为1.48×10^(18)N·m,相当于矩震级M_(W)6.05.地震能量主要在前11 s释放.在深度为6~8 km处破裂速度有明显的变快,可能加剧了地表的震动.

Based on the finite fault inversion method,we investigated the rupture process of the May 2021 Yunnan Yangbi M_(S)6.4 earthquake by regional broadband waveform records.The results indicate that the Yangbi earthquake occurred on a SE-striking right-lateral strike-slip fault.Most of rupture is concentrated in a region to the southeast of the hypocenter,with a maximum slip of 0.55 m located at a depth of about 9 km.The obvious rupture reaches to a depth of about 13 km.The total seismic moment released by the whole fault is 1.48×10^(18)N·m,equivalent to M_(W)6.05.The seismic energy is mainly released in the first 11 s.The rupture velocity becomes significantly faster at a depth of 6~8 km,which may aggravate the surface vibration.