低频前驱波传播机理的研究现状

Review of the research on the propagation mechanism of low-frequency precursory waves

本文从低频前驱波传播的理论与实验等方面对其传播机理的研究现状进行了简要概述。断裂预扩展、过热液体暴沸、粘滑地震前的预滑等均可能产生低频前驱波;微破裂集结、均匀和非均匀断层滑动失稳成核、声透射等实验均证实了岩石在大破裂前确实能够产生一种长周期、小振幅的低频事件;低速断层、壳内低速层、承压含水层、水体大连通性好的灰岩含水层、大气中的声波导层有利于低频前驱波传播。

From the aspects of propagation theory and experiments of low-frequency precursory waves, a review of the research on its propagation mechanism is presented in this paper. Pre-extension of faults, bumping of over-heated liquid and pre-slipping before stick- slip earthquakes all have the possibility to produce low-frequency precursory waves. The experiments of micro-fracture concentration and sound transmission have proved that rocks can produce a type of long-period and small-amplitude low-frequency events. The low-velocity faults, low-velocity layers in the crust, confined aquifers, limestone aquifers with good connectivity of large water unit and the conductive layer of sound wave in the atmosphere are favorable for the propagation of low-frequency precursory waves.