摘要
采用石家庄遥测台网数字化的地震记录,选取了1998年1月～1999年12月张北震区的146条地震,分别对P波、S波作了波谱分析,求取了拐角频率、地震矩、震源半径、应力降、平均位错和波谱能量。分析了拐角频率和应力降随时间的变化趋势,并讨论了震源参数相互之间的关系。结果表明,在1999年3月11日5.6级地震之前应力降和拐角频率均出现异常,同时发现,S波对环境的变化比P波敏感,P波较稳定,且各震源参数与震级有一定相关。
the source spectra of P and S wave for the digital records of 146 earthquakes from Jan. 1998 to Nov. 1999 in Zhangbei area recorded by Shijiazhuang telemetered seismic network are analyzed. In the analysis the corner frequency, seismic moment, focal radius, stress drop, average displacement and spectral energy are calculated. The variation of corner frequency and stress drop with time are analyzed, and the relations between focal parameters are discussed. The results indicated that the stress drop and corner frequency both showed anomalies before Zhangbei M_L5.6 earthquake occurred on Mar.11,1999. Meanwhile, S wave is more sensitive to the change of environment than P wave. The focal parameters are correlative with magnitude in some extent.
出处
《华北地震科学》
2004年第2期6-8,共3页
North China Earthquake Sciences
基金
国家"十五"科技攻关计划(2001BA601B01 01 05)资助
关键词
波谱分析
震源参数
拐角频率
应力降
spectral analysis
focal parameter
corner frequency
stress drop
