New Evidence of Holocene Mass Wasting Events in Recent Volcanic Lakes from the French Massif Central (Lakes Pavin, Montcineyre and Chauvet) and Implications for Natural Hazards

Emmanuel Chapron (1) , Grégoire Ledoux (2) , Anaëlle Simonneau (1) , Patrick Albéric (1) , Guillaume St-Onge (3) , Patrick Lajeunesse (2) , Pierre Boivin (4)

1 ISTO - Institut des Sciences de la Terre d'Orléans - UMR7327
2 CEN - Centre d'Etudes Nordiques
3 ISMER - Institut des Sciences de la MER de Rimouski
4 LMV - Laboratoire Magmas et Volcans

High-resolution seismic profiling (12 kHz) surveys combined with sediment cores, radiocarbon dating, tephrochronology and multibeam bathymetry (when available) allow documentation of a range of Holocene mass wasting events in nearby contrasting lakes of volcanic origin in the French Massif Central (45°N, 2°E): two deep maar lakes (Pavin and Chauvet) and a shallow lake (Montcineyre) dammed by the growth of a volcano. In these lacustrine environments dominated by authigenic sedimentation, recent slide scars, acoustically transparent to chaotic lens-shaped bodies, slump deposits or reworked regional tephra layers suggest that subaqueous mass wasting processes may have been favoured by gas content in the sediments and lake level changes. While these events may have had a limited impact in both lakes Chauvet and Montcineyre, they apparently favoured the development of lacustrine meromicticity in maar Lake Pavin along with possible subaerial debris flows resulting from crater outburst events.

Domaines: Interfaces continentales, environnement; Milieux et Changements globaux

Emmanuel Chapron, Grégoire Ledoux, Anaëlle Simonneau, Patrick Albéric, Guillaume St-Onge, et al.. New Evidence of Holocene Mass Wasting Events in Recent Volcanic Lakes from the French Massif Central (Lakes Pavin, Montcineyre and Chauvet) and Implications for Natural Hazards. 5th International Symposium on Submarine Mass Movements and Their Consequences, Oct 2011, Kyoto, Japan. pp.255-264, ⟨10.1007/978-94-007-2162-3_23⟩. ⟨insu-00707166⟩