French Alpine Foreland Holocene Paleoseismicity Revealed by Coeval Mass Wasting Deposits in Glacial Lakes

Abstract

International audienceThe French alpine foreland area has been struck by several earthquakes with magnitudes above 5 on Richter scale in recent history. In this paper we document the regional impact of historical and Holocene earthquakes based on the identification of mass wasting deposits in glacial lakes at different settings. Lake Le Bourget and Lake Paladru are situated at low elevations (respectively 231 m–492 m) and Lake Blanc Huez is located at 2500 m altitude. Through the integration of high-resolution acoustic profiles and accurately dated sediment samples from cores, recent coeval mass wasting deposits in each lake were correlated with nearby historical earthquakes, whereas coeval mass wasting deposits around 5200 cal BP and 9550 cal BP in these three lakes were correlated to regional earthquakes events

A multi-centennial record of past floods and earthquakes in Valle d'Aosta, Mediterranean Italian Alps

“…return period of ∼ 35 years) suggests a high sensitivity of Lago Inferiore de Laures to earthquake shaking, as such a high frequency of earthquake-induced deposits has rarely been observed in the region (e.g. Guyard et al, 2007;Lauterbach et al, 2012;Simonneau et al, 2013;Strasser et al, 2013;Kremer et al, 2015;Chapron et al, 2016;Wilhelm et al, 2016b). All historical earthquakes are plotted in a "distance vs. epicentral MSK intensity" diagram (e.g.…”

Response to Maarten Van Daele's comments

“…return period of ∼ 35 years) suggests a high sensitivity of Lago Inferiore de Laures to earthquake shaking, as such a high frequency of earthquake-induced deposits has rarely been observed in the region (e.g. Guyard et al, 2007;Lauterbach et al, 2012;Simonneau et al, 2013;Strasser et al, 2013;Kremer et al, 2015;Chapron et al, 2016;Wilhelm et al, 2016b). All historical earthquakes are plotted in a "distance vs. epicentral MSK intensity" diagram (e.g.…”

Historical seismicity of the Mont Dore volcanic province (Auvergne, France) unraveled by a regional lacustrine investigation: New insights about lake sensitivity to earthquakes

“…Usually, the good matching between sedimentary events in lakes and an historical earthquake in the vicinity increases the likelihood for earthquaketriggered deposits, but this method is often limited by the availability and the accuracy of historical reports that rarely goes beyond the last millennium. In Holocene records, the occurrence of synchronous deposits in disconnected basins is a recognized argument for widespread triggering mechanisms such as earthquakes (e.g., Strasser et al, 2013;Moernaut et al, 2014;Pouderoux et al, 2014;Chapron et al, 2016). However, the use of lacustrine archives remains limited by the ability of lake sediments to record earthquakes.…”

“…Today, many studies use various forms of instantaneously formed sedimentary deposits or structures for qualitative and quantitative earthquake reconstructions in lacustrine systems during the Holocene, as long as the seismic origin of these deposits is clear. Most of these studies are concentrated in tectonically active regions such as the Alps (Beck et al, 1996;Schnellmann et al, 2002;Monecke et al, 2004;Nomade et al, 2005;Strasser et al, 2006Strasser et al, , 2013Wilhelm et al, 2015;Chapron et al, 2016), the Anatolian fault (Schwab et al, 2009;Avşar et al, 2014Avşar et al, , 2015 and around the Pacific where recurrent and large earthquakes have been recently experienced such as in Chile (Chapron et al, 2006;Bertrand et al, 2008;Moernaut et al, 2007Moernaut et al, , 2014, US western coast (Karlin et al, 2004;Maloney et al, 2013;Morey et al, 2013;Smith et al, 2013), Japan (Inouchi et al, 1996) or New Zealand (Howarth et al, 2014;Gomez et al, 2015). Moreover, recent limnogeological investigations in glacial lakes of the mid-continental North America underline the ability of sediment to archive earthquakes throughout the Holocene, despite the low to moderate magnitude of earthquakes that occurred in this intraplate domain (St-Onge et al, 2004;Doughty et al, 2014;Lajeunesse et al, in press;Locat et al, 2016).…”