Paper No. 8
Presentation Time: 2:55 PM

CHARACTERIZING LANDSLIDE THREE-DIMENSIONAL VELOCITY, THICKNESS, AND RHEOLOGY FROM REMOTE SENSING


BOOTH, Adam, Geological and Planetary Sciences, California Institute of Technology, MC 170-25, 1200 E. California Blvd, Pasadena, CA 91125, LAMB, M.P., Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Blvd, MC 170-25, Pasadena, CA 91125, AVOUAC, Jean-Philippe, Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Blvd, MC 100-23, Pasadena, CA 91125 and DELACOURT, Christophe, Domaines Océaniques, UMR 6538 CNRS-IUEM-UBO, Place Copernic, F-29280, Plouzané, France, bootha@caltech.edu

Quantifying the velocity, volume, and rheology of deep, slow-moving landslides is essential for hazard prediction and understanding landscape evolution, but existing field-based methods are difficult or impossible to implement at remote sites. Here, we present a novel and widely applicable method for constraining landslide 3D deformation and thickness by inverting surface change data from repeat stereo imagery. Our analysis of La Clapière, a ~ 1 km2 bedrock landslide, reveals a concave-up failure surface with considerable roughness over length scales of tens of meters. Calibrating the thickness model with independent, local thickness measurements, we find a maximum thickness of 163 m and a rheology consistent with distributed deformation of the highly fractured landslide material, rather than sliding of an intact, rigid block. The technique is generally applicable to any mass movements that can be monitored by active or historic remote sensing.