【摘要】 为探索大地震发生前孕震区内微震辐射波谱的变化,在新疆西克尔地区,用选频测震仪对微震波谱进行了观测和研究。选频测震仪分为6个频道,各道中心频率分别为6.0周、8.1周、15.7周、30.0周、50.0周、75.0周。初步结果表明:在一个地震系列中,随着临近较强地震(M_L≥3.2)的发生,微震P波在10周—60周频率范围内的谱值增高,其置信水平一般在70％以上。较强地震发生以后,微震P波在相应频率范围内的谱值下降。 文中还简要地分析了选频地震记录的物理意义,并对较强地震前,微震辐射波谱变化的原因作了初步说明。更多还原

【Abstract】 In order to study the characteristic variations of the spectra of microearthquake waves preceding larger earthquake occurrences, a series of microearthquakes in Xiker region of Xinjang was observed and investigated by using a selected band-pass seis-mograph, which is composed of 6 filtering channels with central frequencies 6 cps, 8.1 cps, 15.7 cps, 30.0 cps, 50.0 cps. 75.0 cps respectively. The preliminary results show that the amplitudes of the spectra of microearthquake P waves in the frequency range 10 cps-60 cps increase before the occurrences of larger earthquakes (ML≥3.2), and decrease after them within the corresponding frequency ranges. The confidence level is more than 70% in general.The physical implication of the recorded effect of the selected band-pass seismo-graph is analysed in brief, and the causes of variation of the microearthquake wave spectra before larger earthquakes are discussed very concisely.更多还原