Earthquake Rupture and Tsunami Generation of the 2015 Mw 5.9 Bonin Event Revealed by In Situ Pressure Gauge Array Observations and Integrated Seismic and Tsunami Wave Simulation
Earthquake Rupture and Tsunami Generation of the 2015 Mw 5.9 Bonin Event Revealed by In Situ Pressure Gauge Array Observations and Integrated Seismic and Tsunami Wave Simulation
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DOI：
10.1029/2021gl095915
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发表时间：
2021-11
影响因子：
5.2
通讯作者：
T. Kubota;Tatsuhiko Saito;Y. Fukao;H. Sugioka;A. Ito;T. Tonegawa;H. Shiobara;M. Yamashita
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作者：
T. Kubota;Tatsuhiko Saito;Y. Fukao;H. Sugioka;A. Ito;T. Tonegawa;H. Shiobara;M. Yamashita
2015年9月1日，小笠原海沟附近发生了一次Mw5.9级板间地震。一组现场海底绝对压力计（APG）观测了其海啸生成场，包括分别由于海啸和地壳变形以及由于地震运动而引起的静态和动态压力变化，其台站密度比以往报道的高得多。我们提出了一种方法来合成的压力变化内的焦点区域，再现APG波形很好。我们进一步成功地估计了地震的有限断层模型，并仅从APG数据约束破裂持续时间。断层模型中相对较低的应力降和地震波辐射可能暗示了海啸地震的性质。现场APG具有很大的潜力，以揭示地震的宽带源过程，这是必要的，以了解俯冲带的地震构造。
On September 1, 2015, an Mw 5.9 interplate earthquake occurred near the Bonin Trench. An array of in situ ocean‐bottom absolute pressure gauges (APGs) observed its tsunami generation field consisting of static and dynamic pressure changes due to tsunami and crustal deformation and due to seismic motion, respectively, under much higher station density than ever reported. We propose an approach to synthesize the pressure change inside the focal area, which reproduces the APG waveforms well. We further successfully estimate the finite fault model of the earthquake and constrain the rupture duration only from the APG data. The relatively low stress drop and seismic wave radiation from the fault model may suggest the nature of a tsunami earthquake. The in situ APGs have a large potential to reveal the broadband source process of the earthquake, which is essential to understand the seismotectonics in the subduction zone.