利用重庆地震台网P波记录测定M_(WP)震级

M_(WP) magnitude calculated with P wave records in Chongqing Seismic Network

选取2010—2016年重庆地震台网记录的M_S>3.0地震,对P波进行波谱分析,得到P波零频极限值、地震矩及拐角周期,拟合得到拐角周期与重庆地震台网M_S的关系、P波零频极限值与重庆地震台网M_S的关系,利用P波地震矩计算矩震级M_(WP),分析M_(WP)与M_S的差异。结果显示,当M_S≤4.0时,M_(WP)>M_S;当M_S>4.0时,M_(WP)<M_S,对得到的震级计算关系式检验发现,P波矩震级及通过零频极限计算得到的震级与重庆地震台网M_S较为接近,而通过拐角周期计算得到的震级与M_S相差较大。

Using the earthquakes with MS3.0 recorded in Chongqing Seismic Network since 2010 to 2016, the amplitude and cycle information, namely the long-period spectral level and the moment and the corner cycle of P wave are gotten through spectrum analysis. The relation between the corner period of P wave and the MS, and the relation between the long-period spectral level of P wave and the MS are obtained. The M（WP） is calculated through the P wave moment. The difference between M（WP） and MS is analyzed. The results show that the M（WP） is larger than MS when MS≤ 4.0, and the M（WP） is smaller than MS when MS4.0. The results of hypothesis testing show that the M（WP）and the magnitude calculated from the long-period spectral level of P wave is relatively close while the magnitude calculated from the P wave corner cycle is in large difference.