ABSTRACT The September 28 2018 Palu tsunami surprised the scientific community, as neither the earthquake magnitude nor its strike-slip mechanism were deemed capable of producing the wave heights that were observed. However, recent research has shown that the earthquake generated several landslides inside Palu bay. The authors conducted a post-disaster field survey of the area affected to collect spatial data on tsunami inundation heights, nearshore and bay bathymetry, and carried out eyewitness interviews to collect testimonies of the event. In addition, numerical simulations of the tsunami generation and propagation mechanisms were carried out and validated with the inferred time series. Seven small submarine landslides were identified along the western shore of the bay, and one large one was reported on the eastern shore of Palu City. Most of these landslides occurred at river mouths and reclamation areas, where soft submarine sediments had accumulated. The numerical simulations support a scenario in which the tsunami waves that arrived at Palu city 4–10 min after the earthquake were caused by the co-seismic seafloor deformation, possibly coupled with secondary waves generated from several submarine landslides. These findings suggest that more comprehensive methodologies and tools need to be used when assessing probabilistic tsunami hazards in narrow bays.

中文翻译：

---

2018 年苏拉威西海啸在帕卢市发生，原因是多次山体滑坡和同震海啸

摘要 2018 年 9 月 28 日的帕卢海啸让科学界感到惊讶，因为无论是地震震级还是走滑机制都被认为无法产生观测到的波高。然而，最近的研究表明，地震在帕卢湾内产生了几次山体滑坡。作者对受灾地区进行了灾后实地调查，以收集有关海啸淹没高度、近岸和海湾测深的空间数据，并进行目击者访谈以收集事件的证词。此外，还对海啸产生和传播机制进行了数值模拟，并使用推断的时间序列进行了验证。在海湾西岸发现了7个小型海底滑坡，在帕卢市东岸报告了1个大型滑坡。这些山体滑坡大部分发生在河口和填海区，在那里积累了柔软的海底沉积物。数值模拟支持这样一种情景，即地震后 4-10 分钟到达帕卢市的海啸波是由同震海底变形引起的，可能与几个海底滑坡产生的二次波相结合。这些发现表明，在评估狭窄海湾的概率海啸灾害时，需要使用更全面的方法和工具。可能与几个海底滑坡产生的二次波相结合。这些发现表明，在评估狭窄海湾的概率海啸灾害时，需要使用更全面的方法和工具。可能与几个海底滑坡产生的二次波相结合。这些发现表明，在评估狭窄海湾的概率海啸灾害时，需要使用更全面的方法和工具。