Scale‐dependence of seismic energy‐to‐moment ratio for strike‐slip earthquakes in Japan
Scale‐dependence of seismic energy‐to‐moment ratio for strike‐slip earthquakes in Japan
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日本走滑地震地震能量矩比的尺度依赖性
DOI：
10.1029/2001gl013402
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发表时间：
2001
影响因子：
5.2
通讯作者：
H. Kanamori
中科院分区：
文献类型：
--
作者：
Y. Izutani;H. Kanamori
我们分析了4对大(MW≈6)和小(MW≈3.5~4)浅层走滑地震，研究了反映地震滑动基本物理过程的一个重要宏观参数--地震能量力矩比的尺度依赖性。这些地震发生在日本西南部，无论是小震还是大震，都有高质量的近距离记录(震中距离和50公里)。这对事件具有几乎相同的震源机制和震源位置。为了消除沿波传播路径的衰减和台址响应的影响，我们使用了成对事件的频谱比。然后，我们根据谱比估计的震源谱估计地震能量。能量力矩比随着地震规模的增大而增大。这种规模依赖关系与早些时候在南加州发现的地震非常相似。
We analyzed four pairs of a large (Mw ≈ 6) and a small (Mw ≈ 3.5 to 4) shallow strike‐slip earthquakes to investigate the scale‐dependence of the seismic energy‐to‐moment ratio, an important macroscopic parameter which reflects the basic physical process of seismic slip. These earthquakes occurred in the south‐western part of Japan, and high‐quality close‐in records (epicentral distance < 50 km) are available for both the small and large earthquakes. The paired events have almost the same focal mechanism and hypocenter location. We used the spectral ratio of the paired events in order to remove the effects of attenuation along the wave propagation path and the station site response. We then estimated the seismic energy from the source spectra estimated from the spectral ratio. The energy‐to‐moment ratio increases with the earthquake size. This scale‐dependence is very similar to that found earlier for earthquakes in Southern California.