摘要
针对过去计算b值的误差 ,提出了两条改进措施 :(1)采用统一的绝对震级标度 -矩震级标度MW ;(2 )舍弃缺失地震次数的点 ,然后用最小二乘拟合求得b值 ,使b值计算较准确 .据此 ,用 3种不同来源和不同精度的资料计算 ,得到的b值都接近于 1.我们固定b值为 0 .85 ,用 13年的现代地震观测资料 ,计算今后 5 0～ 10 0年内较大地震 (外推震级 1～ 2级 )的复发周期 ,结果表明 ,6级和 7级以上地震的复发周期与用近 10 0年的历史地震资料计算得到的复发周期相当一致 ,可以说外推的结果是可靠的 .
Two improvements measurements pointed to the errors to calculating b values have been proposed: (1) to adopt the uniform absolute magnitude scale, seismic moment magnitude M W, (2) to discard the magnitude points for which the earthquakes absent and lose, and then to compute the b value using least square method to fit the data. The b values obtained for three data sets of different precision and sources are close to 1.0 . The occurrence periods of great earthquakes for coming 50～100 year (extend 1～2 magnitude) have been computed using 13 years recent earthquake observation data and fix b0.85. The results demonstrate that the earthquake occurrence periods with magnitude greater than and equal to 7 and 8 are well consistent with that calculated from the data of 100 years history earthquakes, implying the reliable extension.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第4期510-519,共10页
Chinese Journal of Geophysics
基金
国家自然科学基金资助项目 ( 4 98740 10 )
中国地震局地球物理研究所论著号 ( 0 2AC10 2 8) .
关键词
B值
震级
地震复发周期
地震危险性
Earthquake risk , b value, Earthquake occurrence period
