Subaqueous landslide-triggered tsunami hazard for Lake Zurich, Switzerland

Abstract

Subaqueous landslides can induce potentially damaging tsunamis. Tsunamis are not restricted to the marine environment, but have also been documented on lakes in Switzerland and worldwide. For Lake Zurich (central Switzerland), previous work documented multiple, assumedly earthquake-triggered landslides. However, no information about past tsunamis is available for Lake Zurich. In a back-analysis, we model tsunami scenarios as a consequence of the earthquake-triggered landslides in the past. Furthermore, on the basis of a recent map of the earthquake-triggered subaqueous landslide hazard, we present results of a tsunami hazard assessment. The subaqueous landslide progression, wave propagation and inundation are calculated with a combination of open source codes. Although no historic evidence of past tsunamis has been documented for Lake Zurich, a tsunami hazard exists. However, only earthquakes with long return periods are assumed to cause considerable tsunamis. An earthquake with an exceedance probability of 0.5% in 50 years (corresponding to an earthquake with a return period of 9975 years) is assumed to cause tsunamigenic landslides on most lateral slopes of Lake Zurich. A hypothetical tsunami for such an event would create damage especially along the shores of the central basin of Lake Zurich with estimated peak flow depths of up to * 4.6 m. Our results suggest that for an earthquake with an exceedance probability of 10% in 50 years (i.e., mean return period of 475 years), no considerable tsunami hazard is estimated. Even for a worst-case scenario, the cities of Zurich and Rapperswil, located at the northern and southern ends of the lake, respectively, are assumed to experience very little damage. The presented first-order results of estimated wave heights and inundated zones provide valuable information on tsunami-prone areas that can be used for further investigations and mitigation measures.

Geotechnical characterization and stability analysis of subaqueous slopes in Lake Lucerne (Switzerland)

“…5). The failure plane on the nondeltaic slopes is usually inside the glaciolacustrine layer (closer to the bottom part) as it was also discussed in previous studies (Schnellmann et al 2006;Strasser et al 2011;Hilbe and Anselmetti 2015;Strupler et al 2018b). For deltaic slopes, the smallest FS values correspond to the softest and most fine-grained layers in the sediment profile.…”

On the architecture of intra-formational Mass-Transport Deposits: Insights from the carbonate slopes of Great Bahama Bank and the Apulian Carbonate Platform

“…Intra-formational MTDs have been reported from a multitude of modern settings, including river deltas (Field et al, 1982;Christian et al, 1998), glacial environments (Haflidason et al, 2004;Bellwald and Planke, 2018), submarine volcano flanks (Moore et al, 1989;Masson et al, 2002;Gailler and Lénat, 2010), lakes (Schnellmann et al, 2005;Alsop and Marco, 2011;García-Tortosa et al, 2011;Hilbe and Anselmetti, 2015;Kremer et al, 2012Kremer et al, , 2015Strupler et al, 2018;Moernaut et al, 2019) and carbonate slopes (Ten Brink et al, 2006;Principaud et al, 2015;Tournadour et al, 2015). MTDs thus constitute a significant part of many slope and basin-floor successions (Hennuy, 2003;Maslin et al, 2004;Moscardelli and Wood, 2016;Clare et al, 2018).…”

Geometry-Based Preliminary Quantification of Landslide-Induced Impulse Wave Attenuation in Mountain Lakes

“…Further development of the approach should consider different impacting locations along the lakeshore to extend the applicability of the suggested method. Moreover, it would be valuable to consider submerged slide sources, as subaqueous mass movements can also trigger lake impulse waves [47,48].…”