加速度记录测定近震震级在江苏地区的计算研究

基于江苏强震台网和江苏测震台网的地震记录，采用时间域内实时仿真WA记录方法，对2007~2018年记录到的M2.3以上地震进行近震震级测定。为了定量分析基于加速度测定近震震级的可靠性，首先采用国标规定的新震级测定方法和量规函数测定了基于加速度记录的震级，并将结果与江苏测震台网基于速度记录测定的结果进行对比分析，得到线性拟合关系式：ML(ACC)=0.987ML＋1.371；另外计算了15 324组基于加速度测定的震级与人工编目震级之间的绝对偏差，结果显示，偏差在±0.5级以内的结果占87%；通过4阶多项式拟合后发现，在小于200 km范围内测定的震级略低于人工编目的结果，震中距超过200 km后无系统偏差。总体而言，两者结果的一致性较好，表明利用加速度记录仿真WA位移记录来计算近震震级是可行的，得到的结果也是可靠的。

Study on the Calculation of near Earthquake Magnitude Measured by Acceleration Records in Jiangsu Province

Based on the seismic records of Jiangsu strong motion network and Jiangsu seismic network, using the method of real-time simulation of WA records in time domain we carry out ML determination of earthquakes with M≥2.3 recorded from 2007 to 2018.In order to quantitatively analyze the reliability of local magnitude measurement based on acceleration, this paper first uses the determination method and gauge function specified in the new national standard of magnitude to determine the magnitude based on acceleration record, and compares the measured result with that measured by Jiangsu seismic network based on velocity record, and obtains the linear fitting relationship：ML(ACC)=0.987ML+1.371. We also calculate the absolute deviation between 15 324 groups of magnitude based on acceleration measurement and manual cataloging magnitude. The results show that 87% of the results with the deviation are within ±0.5 level.After 4-order polynomial fitting, we find that the magnitude measured in the range of less than 200 km is slightly lower than that of manual cataloging, and there is no systematic deviation after the epicenter distance is 200 km. Generally speaking, the results of the two methods are in good agreement. The results show that it is feasible and reliable to use acceleration records to simulate WA displacement records to calculate ML magnitude.