Simulation of the 2018 Tsunami Due to the Flank Failure of Anak Krakatau Volcano and Implication for Future Observing Systems
Simulation of the 2018 Tsunami Due to the Flank Failure of Anak Krakatau Volcano and Implication for Future Observing Systems
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DOI：
10.1029/2020gl087334
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发表时间：
2020-07-28
影响因子：
5.2
通讯作者：
Aditiya, Arif
中科院分区：
文献类型：
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作者：
Mulia, Iyan E.;Watada, Shingo;Aditiya, Arif
2018年12月22日，喀拉喀托火山侧翼崩塌导致海啸灾难，我们利用滑坡海啸模型探索该地区潜在的海啸观测和预警系统。据估计，西南板块火山大厦的滑坡面积为0.24 km(3)，持续时间相对较短（约3 - 5分钟），在附近引发了40米以上的海啸。然而，海啸在远离产生区传播的过程中迅速减弱，导致巽他海峡周围潮汐计的浪高低于2米。利用海啸模型，我们展示了船舶高度定位方法检测与事件相关的振幅接近20 cm的海啸的能力。此外，吸收高频海洋雷达观测到的海啸流速度可以准确预报沿海海啸高度。2018年12月22日的海啸夺去了印度尼西亚巽他海峡地区数百人的生命。与典型的海啸不同，这次无声的海啸是由喀拉喀托火山的活动引起的。本文通过模拟海啸的产生和传播过程，提出了新的海啸观测和预警系统。虽然震源特征受到有限数据（即卫星图像）的限制，但该模型可以再现潮汐计记录的海啸波形和在指定区域测量的流深。然后，我们进行了数值实验，以评估基于高频海洋雷达和船舶高度定位的潜在海啸观测系统的性能。实验表明，这两个系统都可以作为该地区未来海啸观测的可行方案。
Motivated by the unwarned tsunami disaster caused by the flank collapse of the Anak Krakatau volcano on 22 December 2018, we used a landslide tsunami model to explore potential tsunami observing and warning systems for the region. With the estimated volume of 0.24 km(3) and the relatively short duration (similar to 3 to 5 min), the landslide of the volcanic edifice in the southwest sector triggered a tsunami of higher than 40 m in the vicinity. The tsunami, however, attenuated rapidly as it propagated away from the generation area, resulting in lower than 2 m wave heights at tide gauges around the Sunda Strait. Using the tsunami model, we demonstrated the capability of a ship height positioning method to detect the tsunami of amplitude similar to 20 cm associated with the event. Furthermore, assimilating the tsunami current velocity observed by high-frequency oceanographic radars can produce accurate forecasts of coastal tsunami heights.Plain Language Summary The tsunami on 22 December 2018 claimed hundreds of lives across the Sunda Strait regions of Indonesia. Unlike typical tsunamis, this silent tsunami was caused by the activity of Anak Krakatau volcano. This paper proposes new tsunami observation and warning systems for such a tsunami by modeling the generation and propagation processes. Although the source characteristics are constrained using limited data, that is, satellite images, the model can reproduce tsunami waveforms recorded at tide gauges and flow depths measured at specified regions. We then perform numerical experiments to assess the performance of potential tsunami observing systems based on high-frequency oceanographic radars and ship-height positioning. The experiment suggests that both systems can be viable future tsunami observations in the region.