Synthesizing sea surface height change including seismic waves and tsunami using a dynamic rupture scenario of anticipated Nankai trough earthquakes
Synthesizing sea surface height change including seismic waves and tsunami using a dynamic rupture scenario of anticipated Nankai trough earthquakes
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DOI：
10.1016/j.tecto.2019.228166
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发表时间：
2019-10
期刊：
影响因子：
2.9
通讯作者：
Tatsuhiko Saito;T. Baba;D. Inazu;S. Takemura;E. Fukuyama
中科院分区：
文献类型：
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作者：
Tatsuhiko Saito;T. Baba;D. Inazu;S. Takemura;E. Fukuyama
海上观测技术的发展将为研究人员提供地震震源区内的海啸记录，但这会产生新的问题。由于地震波与海啸在震源区域内共存，因此地震波可能充当海啸信号的噪声。这项研究展示了一种计算地震（包括地震波和海啸）引起的海面高度变化的有效方法。模拟结果表明地震波与海啸重叠；尽管大多数先前的海啸研究都忽略了地震波的贡献，但两者都会影响海面高度的变化。我们还对日本南海海槽可能发生的大地震的预期破裂情景进行了海面位移波场的数值模拟和假设结果。合成的记录可用于评估实时海啸预测方法的性能。此外，我们还讨论了两种海啸波形的异同：海面位移和海底压力变化。虽然两种波形中都出现了地震波，但地震波对海面位移的贡献要低于对海底压力变化的贡献。
The development of offshore observation technology will provide researchers with tsunami records from within an earthquake focal area, but this will create new problems. Because seismic waves coexist with tsunami inside a focal area, the seismic waves could act as noise for the tsunami signal. This study shows an efficient method to calculate sea surface height change caused by an earthquake including both seismic waves and tsunami. Simulation results indicate that seismic waves overlap with tsunami; both affect the change in sea surface height although most previous tsunami studies have neglected the contribution of seismic waves. We also numerically simulated the sea-surface displacement wavefield and hypothesized results for an anticipated rupture scenario of a huge earthquake that may possibly occur in the Nankai Trough, Japan. The synthesized record could be used to evaluate the performance of a real-time tsunami prediction method. Additionally, we discussed the similarity and difference between two kinds of tsunami waveforms: the displacement of the sea surface and the pressure change at the sea bottom. Although seismic waves appeared in both waveforms, the contribution of seismic waves was lower in the displacement at the sea surface than in the pressure change at the sea bottom.