3种钻孔应变仪记录的玛多MS7.4地震同震响应特征对比分析

Comparative Analysis of Coseismic Response Characteristics from Three Borehole Strain Gauges Recorded for the Maduo MS7.4 Earthquake

摘要:

针对2021年5月22日青海玛多M_S7.4地震，采用3种型号的钻孔应变仪观测到的应变资料对比分析同震应变波，结果表明3种仪器记录同震的初动时间、波动幅度和持续时间等存在一定差别：在震中距相当的情况下，TJ型体应变仪和RZB型四分量钻孔应变仪存在波动幅度变化小、持续时间短的问题，难以从背景变化中区分同震响应，影响钻孔仪器同震规律研究；YRY-4型四分量钻孔应变仪波动幅度变化大，持续时间长，在映震效果上表现较为突出。

Abstract:

In view of the M_S7.4 Maduo earthquake in Qinghai Province on May 22, 2021, the coseismic strain waves observed by three types of borehole strain gauges are compared and analyzed. the results show that there exist some differences in the initial motion time, fluctuation amplitude and duration recorded by the three instruments. In the case of the same epicentral distance, TJ type bulk strain gauge and RZB type four-component borehole strain gauge are not good of small fluctuation range and short duration, which makes it difficult to distinguish the coseismic response from the background change, affecting the coseismic law of borehole instrument. the YRY-4 four-component borehole strain gauge has a large fluctuation range and a long duration, and has outstanding performance in seismic reflection effect.