应用近场速度记录快速估算川滇地区中强地震强度

Rapid determination of equivalent moment magnitude of moderately strong earthquakes in the Sichuan-Yunnan region using near-field velocity records

采用Wu等(2004)提出的地震强度测定方法,应用近场速度波形记录,测定地震参数Mew,实现了川滇地区中强地震(MW≥5.7)强度近实时快速测定。Mew是一个与矩震级MW对接的地震参数,与传统的应用振幅测定震级的方法相比,不会存在震级饱和问题,与全球矩心矩张量(GCMT)的矩震级MW具有较好的一致性。该方法解决了应用近场波形资料和矩张量反演方法求取大地震矩震级比较困难的问题,可为区域中强地震速报提供近实时矩震级提供参考,从而提高地震速报的时效性和准确性,同时为强震加速度数据的应用奠定基础。

Using near-field velocity records from regional networks and applying the calculation method of equivalent moment magnitude Mew proposed by Wu et al(2004), the near-real-time rapid determination of the magnitude of moderate-strong earthquakes(MW≥ 5.7) in Sichuan-Yunnan region has been implemented. Mew is an earthquake parameter that is empirically equivalent to the moment magnitude(MW). Compared with other types of earthquake magnitudes that are calculated by measuring maximum amplitudes of seismic waveforms, Mew has no problem of magnitude saturation and its value is consistent with results from GCMT. This method solves the problem that it is difficult to calculate moment magnitudes of large earthquakes using near-field waveform data and moment tensor inversion methods and provides near real-time equivalent moment magnitude reference for quick reporting regional strong earthquakes, thus not only improving the timeliness and accuracy of earthquake quick report but also laying a good foundation for the application of strong-ground-motion acceleration data.