Study of holocene landslide deposits by comparison of GPR, refraction seismic and electrical resistivity data

This paper integrates the results of a geophysical investigation of Holocene landslide events in the Cypress Hills, Canada. Ground penetrating radar (GPR), P-wave refraction seismic and electrical resistivity imaging were used to delineate the boundaries of the landslide masses. GPR provided information about the first meters of the subsurface. The seismic refraction survey complemented the datasets provided by GPR, giving results from greater depths. The electrical resistivity method, in principle the most indicated technique for such clay rich deposits, was used to provide a general structure of the upper 30 meters. Results from two locations provide an overall image of the structure and information about the vertical extent of the landslide. Two different interfaces, that probably mark the top :and the bottom of the landslide, are depicted. In connection with these boundaries, the thickness of the landslide deposits is estimated to increase roughly from 10-15 to more than 20 meters towards the toe of the landslide.