Ocean-influenced Rayleigh waves from outer-rise earthquakes and their effects on durations of long-period ground motion
Ocean-influenced Rayleigh waves from outer-rise earthquakes and their effects on durations of long-period ground motion
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外层地震受海洋影响的瑞利波及其对长周期地震动持续时间的影响
DOI：
10.1093/gji/ggw074
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发表时间：
2016
影响因子：
2.8
通讯作者：
T. Furumura
中科院分区：
文献类型：
--
作者：
S. Noguchi;T. Maeda;T. Furumura
我们调查了在日本东部的外隆地震中广泛观察到的长持续时间（>100 s）、长周期（T= 13-14 s）的瑞利波相位包的原因。由于这一阶段在板间地震的记录中是看不到的，因此认为后期长周期阶段是由于穿越日本海沟的传播而形成的。使用3-D有限差分模拟地震波传播的详细结构模型，包括海底地形和水层，我们证明了后期阶段可以产生的基本模式海洋瑞利波传播在太平洋深处（在6公里的深度），转换为基本模式大陆瑞利波，因为它穿过日本海沟。我们的模型表明，转换是由水深的变化引起的。通过对面波频散的分析，证实了陆地上瑞利波的初至可以由海洋中的第一高阶瑞利波发展而来。这两种瑞利波在陆地上的相继到达，在外隆地震后产生了持续时间很长的地震动。
We investigate the cause of anomalously long duration (>100 s), long-period (T= 13–14 s) phase packets following the Rayleigh wave, which are observed widely in eastern Japan during outer-rise earthquakes. As this phase is not seen in records of interplate earthquakes, the late long-period phase is assumed to develop as a result of propagation across the Japan Trench. Using 3-D finite-difference simulations of seismic wave propagation with a detailed structural model that includes seafloor topography and water layers, we demonstrate that the late phase could be generated by a fundamental-mode oceanic Rayleigh wave propagating in the deep Pacific (at a depth of 6 km), which converts to a fundamental-mode continental Rayleigh wave as it crosses the Japan Trench. Our models suggest that the conversion is caused by the change in bathymetry. Based on analysis of surface wave dispersion, we confirm that the first arrival of the Rayleigh wave on land can develop from the first higher mode oceanic Rayleigh wave. The successive arrivals of the two types of Rayleigh waves on land produce ground motions with very long durations after outer-rise earthquakes.
影响因子：
3
作者：
T. Furumura;T. Hayakawa
通讯作者：
T. Furumura;T. Hayakawa
影响因子：
1.6
作者：
Koketsu, Kazuki;Miyake, Hiroe
通讯作者：
Miyake, Hiroe