华北地区1900-1970年5级以上地震发震位置与震源机制研究

Research of locations and source parameters of historical earthquakes equal and greater than M5.0 from 1900 to 1970 in North China

本文通过整理世界地震台网1900—1970年世界台站震相报告,对该时期发生在我国华北地区震级5级以上强震的震源位置及震源机制(断层面解)进行了测量.具体开展了以下三点工作:(1)使用1900—1970年之间Shide Circulars(BAASSC,1900—1912),《国际地震资料汇编》(ISS)和EHB Bulletin的震相到时,对该时间范围内的22个地震事件重新定位,得到了21个地震事件的可靠结果;(2)使用1933年至1970年之间ISS的P波初动,对该时间范围内的15个地震事件求解震源机制解,得到了其中12个地震事件的震源机制解的可靠结果,从而丰富了华北地区基于全球地震台网观测的1900—1970年历史强震目录震源机制资料;(3)基于华北地区地震地质及区域构造应力场研究结果,推断了华北地区M≥5.0的部分缺乏地震资料观测的历史地震断层面参数,并对这种方法推断的断层面参数的可靠性进行了讨论.

Sorting the global seismic phase report of the seismic network stations during 1900 to1970,this article calculates the hypocenter locations and the focal mechanisms（fault plane solutions）of the earthquakes in North China with magnitude equal and greater than M5.0.This article focuses on three aspects.（1）We relocate 22 events by using the Shide Circulars,International Seismological Summary（ISS）and EHB Bulletin instrumental records within the time span and obtain 21 reliable results.（2）We calculate the focal mechanisms of 15 events by first motion records of P waveforms from ISS and obtain 12 reliable results,so that we enrich the focal mechanism solutions of historical earthquakes from 1900 to 1970 in North China based on the observations of global seismic networks.（3）Based on geological data and the tectonic stress field,we infer focal mechanisms of historical earthquakes（M ≥5.0） from 1900 to 1970 in North China,which lack enough observations from global seismic network,and analyze the uncertainties of the results.