北京地震台宽频带面波震级公式建立

摘要

Using the IASPEI recommended broadband surface madnitudeMBB,we recalculated the surface magnitudeMBB,MKIRNOSandMSK from the seismic recording of BJT station between 1993-2003 which in course of the analog recording system and digital recording system working collaterally. We individually compared the magnitude difference betweenMBB,MKIRNOS andMSK versusMCENC. The comparative result shows us the difference betweenMBB andMCENC was the minimum and the distribution of the magnitude difference followed with the whole delta range was stable. So,we use the least squares technique fi tted the BJT broadband surface wave magnitude calculated formula.%利用IASPEI推荐的宽频震级计算公式MBB，重新量取并计算北京地震台1993—2003年（数字宽频地震记录系统与模拟地震仪器记录并行时期）的MBB、MSK、MKIRNOS震级，并分别同中国地震台网中心发布震级MCENC进行震级偏差比较。对比结果显示：采用宽频带垂直向速度型面波震级的MBB，震级偏差在震中距0°—180°范围内均呈现良好的稳定性，且与中国地震台网中心发布的震级偏差最小。遂利用最小二乘法，采用IASPEI公布的宽频带面波震级计算框架，拟合出北京地震台宽频震级公式。