连云港单台测定m_b震级偏差分析

About magnitude deviation for body wave magnitude determined by Lianyungang Seismic Station

选取2013—2014年连云港地震台单台测定的m_b震级,以中国地震台网中心公布的相应地震震级为标准震级,分析震级偏差平均值、震级大小、震中距、震中方位对震级偏差的影响,并利用稳健回归方法给出震级校正关系式。结果发现:单台震级比中国地震台网中心公布的震级低0.05级;对于中强地震,二者测定结果基本一致;震级偏差随震中距增大逐渐减小,且EN向地震震级偏差较大;采用稳健回归方法校正震级与中国地震台网中心公布震级偏差较小,比较精确。

In this paper, taking the magnitude promulgated by CENC as standard, the body wave magnitude determined by single seismic station in Lianyungang during the year 2013 to 2014 are selected and analyzed for finding out the relationship between the mean magnitude deviation, epicenter distance, and the location of epicenter. Besides, the robust regression method is used to figure out the correction formula of magnitude deviation. The result shows that, (1) mb(LYG) is less than mb(LYG) by 0.05 magnitude. (2) for the moderate earthquake, mb(LYG) is almost the same as mb(CENC).(3) the magnitude deviation is becoming lesser when the epicentral distance is growing longer and the magnitude deviation of earthquakes which happened in the northeast of Lianyungang Seismic Station is maximum. The magnitude deviation after corrected by robust regression method is comparatively smaller and more accurate.