SGER Proposal: Field Survey of the Marquesas Islands

这一行动是对马克萨斯群岛实地调查的部分支持，以确定1946年4月1日阿留申海啸的证据，例如海啸影响马克萨斯群岛时可能留下的水印。在最近对法图希瓦岛海啸的调查中，发现了据报道在1946年阿留申海啸发生时向内陆移动的大岩石，有些高达300米。 这次美国/法国联合考察的目的是记录这些发现，进行测量，并调查马克萨斯其他岛屿上类似海啸岩石的其他轶事报告，并评估1946年4月1日的当地影响。tsunami这项工作非常及时，因为1946年4月1日阿留申海啸的确切生成机制仍然存在争议-通常推测由于大规模山体滑坡而产生了同震海啸。 现有的水动力淹没数据从夏威夷是不足以进行有意义的水动力反演，以确定可能的来源机制。 发现阿留申海啸是否涉及山体滑坡现在非常重要，因为夏威夷的洪水图目前正在重新评估，美国本土太平洋各州的洪水图正在首次开发。 阿留申群岛的海啸是一个需要仔细重新评估的问题，特别是考虑到山体滑坡的可能性。 这些发现还可能有助于重新评估正在进行的海啸滑坡生成工作，自巴布亚新几内亚事件以来，这有助于重新关注全球海啸减灾工作。

This action is for partial support of a field survey of the Marquesas Islands to identify evidence of the April 1, 1946 Aleutian tsunami, such as possible watermarks from the tsunami when it impacted the Marquesas. During a recent survey of a tsunami in the island of Fatu Hiva, large rocks were discovered that had reportedly moved inland in 1946 at about the time of the Aleutian tsunami, some as much as 300m. The objective of this joint US/France expedition is to document these findings, take measurements, and investigate other anecdotal reports of similar tsunami rocks in other islands in the Marquesas, and assess the local impact of the April 1, 1946. tsunami This work is very timely, as the exact generation mechanism of the April 1, 1946 Aleutian tsunami remains controversial -- it is often speculated that there was coseismic tsunami generation due to a massive landslide. The existing hydrodynamic inundation data from Hawaii are not sufficient to perform meaningful hydrodynamic inversion to identify the likely source mechanism. Discovering if a landslide was involved in the Aleutian tsunami is quite important now, as inundation maps for Hawaii are currently being re-evaluated, and inundation maps for the Pacific states of the US mainland are being developed for the first time. Tsunamis from the Aleutians are a concern that needs to be carefully reassessed, particularly in view of the landslide potential. The findings may also help re-evaluate the work in progress on landslide generation of tsunamis, which since the PNG event has helped refocus global tsunami hazard mitigation efforts.