考虑活动地块边界带的分区震级经验关系

地方性震级M_L和面波震级M_S是两种常用的震级标度， 二者经常需要依据经验公式进行相互转换． 基于历史地震整体统计的经验公式由于资料有限， 且没有考虑区域地质条件的差异， 在实际使用中所产生的误差较大． 本文整理了40多年来同时包含M_L和M_S的1万2621条历史地震数据， 通过回归分析得到了震级M_L与M_S的经验关系； 并进一步按照震源所处的Ⅱ级活动地块边界带进行了分区回归分析， 得到了27个分区内地震震级M_L与M_S的经验关系． 结果显示， 经过分区转换后的M_L与M_S具有更好的相关性， 且考虑活动地块边界带所获取的地震震级能有效地降低M_L与M_S之间的转换误差． 

Empirical relationships of earthquake magnitudes for local regions considering the active tectonic boundary areas

Local magnitude M_L and surface wave magnitude M_S are two widely used scales of earthquake magnitude, which usually need to be converted to each other using empirical equations. Due to a limit of data, and ignorance the difference in geological conditions, empirical equations based on historical earthquakes suffer from conversion errors in practice. Based on the historical earthquake data of 12 621 records with both M_L and M_S recorded in the past four decades, this paper derived the empirical conversion equations between M_L and M_S by regression analysis. Furthermore, empirical conversion equations were derived from the partitioned data for the 27 regions classified according to the secondary active tectonic boundary areas. The results show that the correlation between M_S and M_L is more significant after the magnitude data are partitioned, and the magnitudes that were converted with consideration of active tectonic boundaries showed lower conversion error.