Moment tensor inversion of small earthquakes in southwestern Germany for the fault plane solution
Moment tensor inversion of small earthquakes in southwestern Germany for the fault plane solution
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德国西南部小地震矩张量反演断层面解
DOI：
10.1111/j.1365-246x.1990.tb00763.x
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发表时间：
1990
影响因子：
2.8
通讯作者：
K. Bonjer
中科院分区：
文献类型：
--
作者：
J. Ebel;K. Bonjer
摘要本文研究了德国西南部地震事件中直接P波、横波、P波和其他深部体波相的振幅，以研究双偶地震辐射模式的影响。对西德南部黑森林地区6次震级在2.2 ~ 0.5之间的地震进行了震源矩张量的直接P波和s波振幅反演，并从解中提取了双偶分量，进一步进行了反演。纵波和横波振幅的反演震源机制与从大量的首次运动读数中发现的结果非常一致，即使使用了非常不同的地壳模型。对于1.4级或以上的地震，仅使用直接p波振幅的反演也获得了良好的震源机制。此外，在距离最大事件P，，距离的站点的垂直分量记录成功地合成了代表从逆温中发现的那些局部机制。模拟的相位包括P、PmP和几个自由面反射。地震辐射模式的影响还体现在另外两次地震的一组方位分布台站到达的P， 0的振幅上。本研究证实了震源机制的直接P和S振幅可以被反演，并表明更深的地壳相，如P…PmP等，也受到地震辐射模式的影响。
SUMMARY The amplitudes of direct P- and S-waves as well as P,, and other deep crustal body-wave phases from events in southwestern Germany are studied for the effects of the double-couple earthquake radiation pattern. The direct P- and S-wave amplitudes for six earthquakes in the southern Black Forest of West Germany with magnitudes between 2.2 and 0.5 were inverted for the source moment tensor, and the double-couple components were extracted from the solutions and refined by a further inversion. The inversion focal mechanisms using both P- and S-wave amplitudes were quite consistent with those found from a large set of first motion readings, even when very different crustal models were used. For the events at or above magnitude 1.4, inversions using only direct P-wave amplitudes also yielded good focal mechanisms. Furthermore, the vertical component record at a station at P,, distance from the largest of the events was successfully synthesized using local mechanisms representative of those found from the inversions. The phases modelled included P,,, PmP and several free-surface reflections. The effect of the earthquake radiation pattern was also noted in the amplitudes of the P,, arrivals of a set of azimuthally distributed stations for two other earthquakes. This study confirms that direct P and S amplitudes can be inverted for the source focal mechanism and suggests that deeper crustal phases, like P,,, PmP, etc., are also affected by the earthquake radiation pattern.