气候变化领域集成服务门户(CCPortal): A tsunamigenic delta collapse and its associated tsunami deposits in and around Lake Sils, Switzerland

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DOI	10.1007/s11069-021-04533-y
	A tsunamigenic delta collapse and its associated tsunami deposits in and around Lake Sils, Switzerland
	Nigg V.; Wohlwend S.; Hilbe M.; Bellwald B.; Fabbri S.C.; de Souza G.F.; Donau F.; Grischott R.; Strasser M.; Anselmetti F.S.
发表日期	2021
ISSN	0921030X
起始页码	1069
结束页码	1103
卷号	107 期号:2
英文摘要	Large lacustrine mass movements and delta collapses are increasingly being considered as potential tsunamigenic sources and therefore hazardous for the population and infrastructure along lakeshores. Although historical reports document tsunami events in several lakes in Switzerland, and although the propagation of lake tsunamis has been studied by numerical wave modeling, only little is known about on- and offshore lacustrine tsunami deposits. In Lake Sils, Switzerland, a large prehistoric mass-movement deposit originating from the Isola Delta with a minimum estimated volume of 6.5 × 106 m3 and a basinal thickness of > 6 m in the seismic record has been identified by previous studies and radiocarbon dated to around 700 Common Era. Here, we combine (i) comprehensive sedimentological investigation of sediment cores recovered from the on- and offshore settings, (ii) mineralogical fingerprinting of the inflows from key catchments to characterize sediment provenance, and (iii) numerical tsunami modeling, to test the hypothesis of a tsunamigenic delta collapse in Lake Sils. We observe a clastic event deposit consisting of coarse-grained, fining-upward sand overlying an organic-rich peat deposit in the shallow water. This layer thins and fines landward on the coastal plain. Toward the deeper water (20–40 m), the deposit transforms into a thicker and more heterogeneous sediment package with multiple sequences of fining-upward sand and a well-pronounced clay cap at the top. Radiocarbon dating of the peat underlying the event deposit yields a maximum age of 225–419 calibrated Common Era. The tsunami models, which indicate wave heights reaching up to 5 m, simulate areas of inundation that coincide with the location of event deposits. Based on our results, we propose that the historically undocumented Isola Delta collapse generated a basin-wide tsunami that inundated the lakeshore, transporting large amounts of unconsolidated sediment along the lakeshore toward the coastal plain and into the deeper lake basin. © 2021, The Author(s).
关键词	Delta collapse Lacustrine tsunami Sedimentology Tsunami deposit Tsunami modeling
英文关键词	coastal plain; collapse; disaster management; hazard management; mass movement; natural hazard; tsunami; Graubunden; Lake Sils; Switzerland
语种	英语
来源期刊	Natural Hazards
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/206455
作者单位	Institute of Geological Sciences and Oeschger Centre for Climate Change Research, University of Bern, Baltzerstrasse 1+3, Bern, 3012, Switzerland; Geological Institute, ETH Zurich, Sonneggstrasse 5, Zürich, 8092, Switzerland; Volcanic Basin Petroleum Research (VBPR), Høienhald, Blindernveien 5, Oslo, 0361, Norway; Institute of Geochemistry and Petrology, ETH Zurich, Clausiusstrasse 25, Zürich, 8092, Switzerland; Department of Geology, University of Innsbruck, Innrain 52, Innsbruck, 6020, Austria
推荐引用方式 GB/T 7714	Nigg V.,Wohlwend S.,Hilbe M.,et al. A tsunamigenic delta collapse and its associated tsunami deposits in and around Lake Sils, Switzerland[J],2021,107(2).
APA	Nigg V..,Wohlwend S..,Hilbe M..,Bellwald B..,Fabbri S.C..,...&Anselmetti F.S..(2021).A tsunamigenic delta collapse and its associated tsunami deposits in and around Lake Sils, Switzerland.Natural Hazards,107(2).
MLA	Nigg V.,et al."A tsunamigenic delta collapse and its associated tsunami deposits in and around Lake Sils, Switzerland".Natural Hazards 107.2(2021).