Abstract On 28th September 2018, an earthquake of Mw 7.5 struck Donggala Regency, Central Sulawesi, Indonesia, resulting in a catastrophic disaster and a large numbers of casualties. In this report, the results of the preliminary field investigations carried out by the authors’ team are summarized. The earthquake caused four major long-distance flow-slides on very gentle slopes of approximately 1–5% in and around Palu City: Balaroa, Petobo, Jono Oge and Sibalaya. The maximum flow distance at each site was several hundred meters or more. Spring waters were found in all affected areas even though there had not been a lot of rainfall before the survey. Interviews with local residents and witnesses of the flow-slide provided much evidence that the shallow groundwater in the affected areas had been pressurized before the earthquake. This confined groundwater is thought to have played an important role in the occurrence of long-distance flow-slide. In addition, the thickness of the flowed ground was found to be about 1.5 m by pit excavation survey in Jono Oge. Based on the results of the field survey and provided evidence, the likely fundamental mechanisms of the flow-slide are discussed.

中文翻译：

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2018年印度尼西亚苏拉威西地震引起的长距离滑坡概况

摘要 2018 年 9 月 28 日，印度尼西亚中苏拉威西省东加拉县发生 7.5 级地震，造成灾难性灾难和大量人员伤亡。本报告总结了作者团队进行的初步实地调查的结果。地震在帕卢市及其周边大约 1-5% 的非常平缓的斜坡上造成了四次主要的长距离水流滑坡：巴拉罗阿、佩托博、城诺奥格和西巴拉亚。每个站点的最大流动距离为数百米或更长。尽管在调查之前没有大量降雨，但在所有受影响的地区都发现了泉水。对当地居民和水流滑坡目击者的采访提供了大量证据，证明受灾地区的浅层地下水在地震前已经加压。这种承压地下水被认为在长距离滑坡的发生中起了重要作用。此外，在城野尾毛的坑洞开挖调查中发现流过的地面厚度约为 1.5 m。根据实地调查的结果和提供的证据，讨论了流动滑坡可能的基本机制。