新疆数字地震台网地方性震级量规函数的初步研究

Calibration Function of Local Magnitude for the Xinjiang Digital Seismic Network

基于2009～2014年新疆测震台网数字地震记录资料,运用震级残差统计方法,选择16269个2.0≤ML≤5.4地震事件,共计获得了179561个单台记录;利用最大地动位移衰减特性方法,选用3.6≤ML≤4.5的746个地震事件作为研究对象,对新疆数字台网地方性震级量规函数进行了研究。将得出的量规函数值进行对比后认为,现阶段使用的量规函数值在0～200km的震中距范围内偏小,导致此范围内台站测定的震级偏小;在200～800km的范围内,测算的震级值较稳定,偏差范围在±0.1的范围内;在400～800km震中距范围内,由最大地动位移衰减特性方法得出的量规函数偏小。由于目前各地震台站使用的地震计仪器响应不准确,造成量规函数偏小的原因有待用计量更加准确的台站仪器响应参数进行验证,以便得到更加精确的新疆台网地方性震级量规函数。

Using the data of seismic records of Xinjiang Digital Seismic Network during2009-2014, We study the local magnitude calibration function of the Xinjiang Digital Seismic Network through two kinds of methods : the magnitude residual statistics and the maximum displacement attenuation characteristics. In the range of 0-200 km epicentral distance the calibration function of the currently used values is small through comparing the calibration function value. That’s why the station measured magnitude is always small in this range. In the range of 200-800 km, the magnitude of the measured value is more stable. The deviation is within the range of plus or minus 0.1. In the range of 400-800 km,the calibration function is small from the maximum displacement attenuation relationship. At present the most station seismometer instrument response is not accurate. The cause of small calibration functions needs more accurate seismometer instrument response to verification in order to get more accurate local magnitude calibration function of Xinjiang Digital Seismic Network.