A Study of the 2015 Mw 8.3 Illapel Earthquake and Tsunami: Numerical and Analytical Approaches
A Study of the 2015 Mw 8.3 Illapel Earthquake and Tsunami: Numerical and Analytical Approaches
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2015 年 Mw 8.3 伊拉佩尔地震和海啸研究：数值和分析方法
DOI：
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发表时间：
2016
影响因子：
2
通讯作者：
A. Villalobos
中科院分区：
文献类型：
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作者：
M. Fuentes;S. Riquelme;G. Hayes;M. Medina;D. Melgar;G. Vargas;J. Gonzalez;A. Villalobos
2015年9月16日智利伊拉佩尔地震引发特大海啸，造成经济损失和人员伤亡。为了研究这次地震对海岸的影响，并了解如何在未来准确地模拟此类灾害，我们使用伊拉佩尔破裂的不同有限断层模型来定义海啸模拟的初始条件。采用数字代码“海洋波浪非静水力演化”(NEOWAVE) 来模拟太平洋海啸的演变。由于应急反应的时间很短，而且地震和海啸的震源都靠近海岸，因此快速了解近场爬升行为对智利来说非常重要。因此，考虑2+1D浅水波浪方程的解析解。通过这个解决方案，我们表明我们可以快速估计沿海岸线的助跑分布，一阶。地震和海啸发生后，在周围的沿海地区进行了现场观测，海啸导致了那里的海水大幅上升。首先，我们比较解析解和数值解，以测试解析方法和现场观测的准确性，这意味着解析方法可以准确地模拟地震后海啸的形成，而无需牺牲完整数值反演所需的时间。然后，我们将两者与现场启动测量进行比较。我们观察到两种方法之间的一致性。为了完成分析，仅使用启动现场测量来执行海啸源反演。将这些反演结果与地震模型进行比较，并显示可以捕获这些模型的大范围细节，而无需反演详细的数据集。
The September 16, 2015 Illapel, Chile earthquake triggered a large tsunami, causing both economic losses and fatalities. To study the coastal effects of this earthquake, and to understand how such hazards might be accurately modeled in the future, different finite fault models of the Illapel rupture are used to define the initial condition for tsunami simulation. The numerical code Non-hydrostatic Evolution of Ocean WAVEs (NEOWAVE) is employed to model the tsunami evolution through the Pacific Ocean. Because only a short time is available for emergency response, and since the earthquake and tsunami sources are close to the coast, gaining a rapid understanding of the near-field run-up behavior is highly relevant to Chile. Therefore, an analytical solution of the 2 + 1 D shallow water wave equations is considered. With this solution, we show that we can quickly estimate the run-up distribution along the coastline, to first order. After the earthquake and tsunami, field observations were measured in the surrounded coastal region, where the tsunami resulted in significant run-up. First, we compare the analytical and numerical solutions to test the accuracy of the analytical approach and the field observations, implying the analytic approach can accurately model tsunami run-up after an earthquake, without sacrificing the time necessary for a full numerical inversion. Then, we compare both with field run-up measurements. We observe the consistency between the two approaches. To complete the analysis, a tsunami source inversion is performed using run-up field measurements only. These inversion results are compared with seismic models, and are shown to capture the broad-scale details of those models, without the necessity of the detailed data sets they invert.