论文部分内容阅读
在离1995年兵库县南部地震(M=7.2)震源区近100km的两个台上观测到脉冲式的同震地磁变化。在该主震时其最大幅度为0.6～1.0nT,而持续时间为20～30s。在发震时刻及其之后17s地震波到达观测点之前,这些变化看来就已经开始了。对余震的叠加时间分析亦揭示了类似的地磁变化,尽管其幅度比主震时小一个量级。作为这种同震地磁变化的可能原因,讨论了地壳电动机制。
Pulsed coseismic geomagnetic changes were observed on two stations nearly 100 km from the source region of the southern Hyogo earthquake in 1995 (M = 7.2). The maximum magnitude of the main shock is 0.6 ~ 1.0nT, while the duration is 20 ~ 30s. These changes seem to have started before the onset of the earthquake and the subsequent arrival of the 17-s seismic wave at the observation point. The superimposed time analysis of aftershocks also revealed similar geomagnetic changes, albeit at orders of magnitude smaller than the mainshock. As a possible cause of this coseismic geomagnetic change, the crustal electric mechanism is discussed.