Seismic interferometry facilitating the imaging of shallow seismic reflectors hidden beneath surface waves

Abstract

High-resolution reflection seismics can be very helpful in subsurface imaging and monitoring in urban environments and in archaeological sites. An obstacle that hinders the success of high-resolution reflection seismic imaging of the very shallow targets is the presence of source-generated surface waves at soil-covered sites and surface waves generated by other anthrogenic sources, e.g., traffic and construction activities in the vicinity of the seismic line. Both of these can hide the very shallow reflection events. We have developed new schemes involving seismic interferometry (SI) to retrieve both source-coherent (and/or source-incoherent) surface waves part of data. The retrieved surface waves are then adaptively subtracted from the raw data, thereby exposing hidden reflections. We illustrate results on both synthetic and field seismic data. We show that artefacts caused by stacking the surface-wave noise are greatly reduced, and that reflectors, especially at very shallow depth, can be much better imaged and interpreted.