The 2018 Anak Krakatoa volcano flank collapse generated a tsunami that impacted the Sunda Strait coastlines. In the absence of a tsunami early warning system, it caused several hundred fatalities. There are ongoing discussions to understand how the failure mechanism of this event affected landslide dynamics and tsunami generation. In this paper, the sensitivity to different failure scenarios on the tsunami generation is investigated through numerical modelling. To this end, the rate of mass release, the landslide volume, the material yield strength, and orientation of the landslide failure plane are varied to shed light on the failure mechanism, landslide evolution, and tsunami generation. We model the landslide dynamics using the depth-averaged viscoplastic flow model BingClaw, coupled with depth-averaged long wave and shallow water type models to simulated tsunami propagation. We are able to match fairly well the observed tsunami surface elevation amplitudes and inundation heights in selected area with the numerical simulations. However, as observed by other authors, discrepancies in simulated and observed arrival times for some of the offshore gauges are found, which raises questions related to the accuracy of the available bathymetry. For this purpose, further sensitivity studies changing the bathymetric depth near the source area are carried out. With this alteration we are also able to match better the arrival times of the waves.

中文翻译：

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建模 2018 Anak Krakatoa 侧翼坍塌和海啸：滑坡破坏机制和动力学对海啸产生的影响

2018 年 Anak Krakatoa 火山侧翼坍塌引发了海啸，影响了巽他海峡海岸线。在没有海啸预警系统的情况下，造成数百人死亡。正在进行讨论以了解该事件的失效机制如何影响滑坡动力学和海啸的产生。在本文中，通过数值建模研究了对海啸产生的不同故障场景的敏感性。为此，质量释放速率、滑坡体积、材料屈服强度和滑坡破坏面的方向发生变化，以揭示破坏机制、滑坡演化和海啸的产生。我们使用深度平均粘塑性流动模型 BingClaw 模拟滑坡动力学，结合深度平均长波和浅水型模型来模拟海啸传播。我们能够将在选定区域内观测到的海啸表面高程振幅和淹没高度与数值模拟相匹配。然而，正如其他作者所观察到的那样，发现一些离岸测量仪的模拟到达时间和观察到的到达时间存在差异，这引发了与可用水深测量准确性相关的问题。为此，开展了改变源区附近测深深度的进一步敏感性研究。通过这种改变，我们还能够更好地匹配波浪的到达时间。然而，正如其他作者所观察到的那样，发现一些离岸测量仪的模拟到达时间和观察到的到达时间存在差异，这引发了与可用水深测量准确性相关的问题。为此，进行了进一步的敏感性研究，改变了源区附近的测深深度。通过这种改变，我们还能够更好地匹配波浪的到达时间。然而，正如其他作者所观察到的那样，发现一些离岸测量仪的模拟到达时间和观察到的到达时间存在差异，这引发了与可用水深测量准确性相关的问题。为此，进行了进一步的敏感性研究，改变了源区附近的测深深度。通过这种改变，我们还能够更好地匹配波浪的到达时间。