Earthquake source mechanism determination by use of body-wave amplitudes—An application to Swedish earthquakes
Earthquake source mechanism determination by use of body-wave amplitudes—An application to Swedish earthquakes
复制标题
利用体波振幅确定震源机制——在瑞典地震中的应用
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
R. Slunga
中科院分区：
文献类型：
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作者：
R. Slunga
提出了一种基于极性和振幅观测相结合的震源研究方法。它利用了观测到的体波脉冲，避免了在定向角和地震矩之外引入额外的震源参数。提出了一种统计模型，并将该方法应用于瑞典3 ~ 5个台站在20 ~ 100 km范围内记录的5次小地震。这些地震的地震矩在0.6 ~ 10 × 10 11 N-m （1 N-m = 10.7达因-cm）之间。尽管其中4次地震只使用了两个或更少的极性，但由此产生的机制在统计上是显著的，而且定义得很好。求解结果接近1976年芬兰湾大地震（M o = 3.5 × 10 15 N-m）的机制。它们都表示在E-W至se - nnw扇区的水平主压应力。本文中振幅观测的成功应用表明，震源机制反演仅可基于极少数近距离台站的记录进行。
abstract A method for earthquake source studies based on a combined use of polarity and amplitude observations is proposed. It makes use of the impulses of the observed body waves to avoid the introduction of additional source parameters besides the orientation angles and seismic moments. A statistical model is proposed and the method is applied to five small earthquakes in Sweden recorded by 3 to 5 stations in the distance range of 20 to 100 km. The seismic moments of these earthquakes are in the range of 0.6 to 10 × 10 11 N-m (1 N-m = 10 7 dyne-cm). The resulting mechanisms are statistically significant and well defined in spite of the fact that for four of the earthquakes, only two or less polarities are used. Furthermore, the solutions are close to the mechanism of the major ( M o = 3.5 × 10 15 N-m) earthquake in the Gulf of Finland 1976. They all indicate horizontal principal compressive stresses in the sector E-W to SSE-NNW. The successful use of amplitude observations presented in this paper shows that source mechanism inversion can be made based on recordings at only a very few close stations.