Seismological evidence on characteristic time of crack healing in the shallow crust
Seismological evidence on characteristic time of crack healing in the shallow crust
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DOI：
10.1029/2005gl022657
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发表时间：
2005-05
影响因子：
5.2
通讯作者：
Y. Hiramatsu;H. Honma;A. Saiga;M. Furumoto;Tooru Ooida
中科院分区：
文献类型：
--
作者：
Y. Hiramatsu;H. Honma;A. Saiga;M. Furumoto;Tooru Ooida
对日本东海地区近17年的剪切波分裂观测表明，在一次较大的地震（MW5.7）作用下，地壳浅层的地震各向异性存在一种独特的时间变化。快速和慢速子波之间的延迟时间同震增加，然后减少到事件前的值。下降阶段的持续时间约为两年。这种减少可能表明地壳上部10公里处的裂缝正在愈合。我们近似的时间变化的延迟时间作为对数的时间，这是一致的愈合现象的裂缝实验室报告。观察表明，地壳岩石中的裂缝愈合大约在两年内完成。
A continuous observation of shear wave splitting for 17 years reveals a unique temporal variation in seismic anisotropy in the shallow crust induced by a larger earthquake (MW5.7) beneath the Tokai region, Japan. The delay time between the fast and slow wavelets coseismically increased and then decreased back to the pre‐event value. The duration of the decreasing stage is about two years. The decrease may indicate crack healing in the upper 10 km of the crust. We approximate the temporal variation in the delay time as a function of logarithm of time, which is concordant with healing phenomena of cracks reported by laboratory experiments. The observation indicates that healing of cracks in crustal rocks is complete in approximately two years.