Interface wave studies on the Ligurian shelf usingan OBS array: experimental results and propagation models

Abstract

Seismic waves travelling in the water/sediment or subbottom sediment/sediment interface have been the subject of considerable interest in recent years. Experiments have confirmed the existence of interface waves in different geological environments. Some progress has been made in understanding the propagation and attenuation characteristics of these waves. However, the generating mechanisms are poorly understood. In particular, what are the roles of geometry and bottom characteristics in coupling waterborne sound into the sea bottom? What is the acoustic-toseismic energy conversion process? Using explosives as sound sources, an experiment was performed in which the propagation along different interface paths was measured by an array of three tri-axial ocean bottom seismometers. To obtain realistic input data for the propagation models, continuous seismic profiles were run and cores were taken along the propagation path. Results of these experiments and a comparison of measured and modelled dataare presented.