Application of geophysical methods for the investigation of the large gravitational mass movement of Séchilienne, France

Abstract

International audienceSeveral geophysical techniques (electromagnetic profiling, electrical tomography, seismic refraction tomography, and spontaneous potential and seismic noise measurement) were applied in the investigation of the large gravitational mass movement of Séchilienne. France. The aim of this study was to test the ability of these methods to characterize and delineate the rock mass affected by this complex movement in mica schists, whose lateral and vertical limits are still uncertain. A major observation of this study is that all the zones strongly deformed (previously and at present) by the movement are characterized by high electrical resistivity values (>3 kΩ·m), in contrast to the undisturbed mass, which exhibits resistivity values between a few hundred and 1 kΩ·m. As shown by the surface observations and the seismic results, this resistivity increase is due to a high degree of fracturing associated with the creation of air-filled voids inside the mass. Other geophysical techniques were tested along a horizontal transect through the movement, and an outstanding coherency appeared between the geophysical anomalies and the displacement rate curve. These preliminary results illustrate the benefits of combined geophysical techniques for characterizing the rock mass involved in the movement. Results also suggest that monitoring the evolution of the rock mass movement with time-lapse geophysical surveys could be beneficial

An efficient workflow to accurately compute groundwater recharge for the study of rainfall-triggered deep-seated landslides, application to the Séchilienne unstable slope (western Alps)

“…The landslide shows a higher hydraulic conductivity than the underlying stable bedrock (Vengeon, 1998;Meric et al, 2005;Le Roux et al, 2011), thus leading to a landslide perched aquifer (Guglielmi et al, 2002). The recharge of the landslide perched aquifer is essentially local, enhanced by the trenches and the counterscarps which tend to limit the runoff and to facilitate groundwater infiltration in the landslide area.…”

Electrical imaging of sliding geometry and fluids associated with a deep seated landslide (La Clapière, France)

“…Comparisons in other well known cases of deep seated landslides such as the Séchilienne landslide (Meric et al, 2005) or the Rosone slope (Binet et al, 2007) should also be conducted in order to validate the methodology at this scale.…”

Integrated Seismic Survey for Detecting Landslide Effects on High Speed Rail Line at Istanbul–Turkey

“…This method has been widely used to model the landslides [e.g. [6][7][8]. It is observed that lateral velocity changes can be imaged competently by the use of the seismic tomography method [9] and [10] the utilized seismic tomography.…”