DOI: 10.1007/s11069-021-04533-y
论文题名: A tsunamigenic delta collapse and its associated tsunami deposits in and around Lake Sils, Switzerland
作者: Nigg V. ; Wohlwend S. ; Hilbe M. ; Bellwald B. ; Fabbri S.C. ; de Souza G.F. ; Donau F. ; Grischott R. ; Strasser M. ; Anselmetti F.S.
刊名: Natural Hazards
ISSN: 0921030X
出版年: 2021
卷: 107, 期: 2 起始页码: 1069
结束页码: 1103
语种: 英语
中文关键词: 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
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). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/169254
Appears in Collections: 气候变化与战略
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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
Recommended Citation:
Nigg V.,Wohlwend S.,Hilbe M.,et al. A tsunamigenic delta collapse and its associated tsunami deposits in and around Lake Sils, Switzerland[J]. Natural Hazards,2021-01-01,107(2)