SH-wave seismic reflection at the Patigno Landslide and integration with P-wave reflection data

In this work we describe the acquisition and processing, up to the depth migrated image, of an SH-wave reflection seismic survey carried out on a complex deep seated landslide located in the Northern Apennines in Italy. We also show a comparison with a recently acquired P-wave seismic reflection profile that investigates the same landslide body. The P-wave survey was able to delineate the deep sliding discontinuity, but was unable to give a detailed description of the small reactivation slip surfaces delineating minor landslides at shallow depths, that are responsible of the major observed damages. Our experience shows that the combined use of both P-waves and SH-waves offers the possibility to obtain detailed insights of the whole landslide body from the deepest discontinuity up to the very shallow portion of the landslide, overcoming the limitations due to the low resolution of P-wave method for imaging shallow horizons and the low investigation depth of SH-wave method. The deeper knowledge of the landslide internal setting that can be gained by a joint application of both methodologies is of primary importance to plan adequate and effective defence strategies.