Silent earthquakes occurring in a stable-unstable transition zone and implications for earthquake prediction
Silent earthquakes occurring in a stable-unstable transition zone and implications for earthquake prediction
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稳定-不稳定过渡带发生的无声地震及其对地震预测的影响
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
I. Kawasaki
中科院分区：
文献类型：
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作者：
I. Kawasaki
在过去的十年中，在日本的南海和相模海槽（形成菲律宾海板块的西北边缘）沿线沿着记录了九次无声地震。它们发生在稳定-不稳定的过渡带，深度约30公里的俯冲界面上，并从1923年关东，1944年东南海和1946年南海地震的主要凹凸分离。它们的等效震级小于7级，总滑动量小于0.2m，比一般大地震的大凸体小一个数量级。静地震的矩释放率小于1014 Nm/s，比大地震的1019 Nm/s小5个数量级。尝试了两种方法来获得一些无声地震震源区粗糙度和摩擦参数的量级估计。一种方法是根据实验室实验，采用经验震源时间函数，将观测波形与合成波形进行比较。另一种是将静地震的大小与摩擦参数a-b联系起来。
In the past decade, nine silent earthquakes were documented along the Nankai and the Sagami Troughs in Japan, which form the northwestern margin of the Philippine Sea plate. They occurred in the stable-unstable transition zone at depths of around 30 km on the subduction interface and were segregated from major asperities of the 1923 Kanto, the 1944 Tonankai and the 1946 Nankai earthquakes. Their equivalent magnitudes were less than 7 and overall slips were less than 0.2 m, one-order smaller than those of the major asperities of ordinary great earthquakes. Moment release rates of the silent earthquakes were less than 1014 Nm/s, five-orders smaller than 1019 Nm/s of the great earthquakes. Two methodologies are attempted to obtain order of magnitude estimates of the roughness and friction parameter of source areas of some of the silent earthquakes. One method compares observed waveforms to synthetics with an empirical source time function based on laboratory experiment. The other relates sizes of silent earthquakes to the friction parameter a-b.