基于重力观测的巴颜喀拉块体强震震级模拟分析

Simulation analysis of strong earthquake magnitude in Bayankala block based on gravity observation

以内蒙古乌加河地震台的连续重力观测资料为基础,应用PET重力仪采样率较高的特点,分析了PET相对重力仪与JCZ-1甚宽带地震仪的波形相关关系及同震形变物理特征。通过模拟分析乌加河地震台PET相对重力仪记录到巴颜喀拉块体周围发生的6次7级以上强地震的同震P波、S波及面波与震中距离、震级的相关关系,得出一般震级模型、地应力波模型和S波P波幅度比模型公式。通过计算3种震级模型理论震级与实际震级的误差及相关系数R值,得到理论震级与实测震级标准误差达到0.04,R值达到0.99,验证了模型的可靠性。对比分析理论震级与实际震级的误差与R值,揭示同震形变波形蕴含地球动力特征的物理机制。

Based on the continuous gravity observation data of Wujiahe seismic station in Inner Mongolia,the waveform correlation between PET relative gravimeter and JCZ-1 very broadband seismometer and the physical characteristics of coseismic deformation are analyzed using the high sampling rate of PET gravimeter.By simulating and analyzing the correlation between the coseismic P-wave,S-wave and surface wave with epicentral distance and magnitude of six strong earthquakes with M≥7 occurred around Bayankala block recorded by PET relative gravimeter at Wujiahe seismic station,the general magnitude model,in-situ stress wave model and S-wave P-wave amplitude ratio model are obtained.By calculating the error and correlation coefficient R value between the theoretical magnitude and the actual magnitude of the three models,the standard error between the theoretical magnitude and the measured magnitude is 0.04,and the R value is 0.99,which verifies the reliability of the model.The error and R value of theoretical magnitude and actual magnitude are compared and analyzed to reveal the physical mechanism of geodynamic characteristics contained in coseismic deformation waveform.