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arXiv 1508.04873physics.geo-ph
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尾波的起源:震源共振

Origin of coda waves: earthquake source resonance

Yinbin Liu

摘要:

当地地震中的尾波表现出类似共振的波动行为,其中尾波表现为具有选择频率的长持续时间小振幅振动,时间衰减缓慢,并且在震源周围具有均匀的空间能量分布。尾波被认为是地球岩石圈中随机小尺度不均匀性散射的非相干波。在这里,我表明,尾波主要是由于在强小尺度的非均匀性,通过地震波场模拟的一维非均匀性地震的震源周围的自然共振。自然共振是由瞬态状态下的低频共振演化而来,是发生在恒定状态下的一种突发现象。它的共振频率随着非均匀尺度、阻抗对比度或随机非均匀尺度和速度波动的增加而减小;它的强度随着阻抗对比度的减小或随机非均匀尺度和速度波动的增加而减小。

英文摘要:

Coda in local earthquake exhibits resonance-like wave behaviour where the coda emerges as long-duration small-amplitude vibration with selective frequency, slow temporal decay, and uniform spatial energy distribution around the earthquake source. Coda is thought to be the incoherent waves scattered from random small-scale heterogeneity in the earth's lithosphere. Here I show that the coda is primarily attributed to the natural resonance in strong small-scale heterogeneity around the earthquake's hypocenter through seismic wave field modeling for 1D heterogeneity. The natural resonance is evolved from the low frequency resonance (LFR) in transient regime and is an emergent phenomenon that occurs in steady state regime. Its resonance frequency decreases with increasing heterogeneous scale, impedance contrast, or random heterogeneous scale and velocity fluctuations; its intensity diminishes with decreasing impedance contrast or increasing random heterogeneous scale and velocity fluctuations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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