Towed Marine Dipole Source for Shear Wave Generation

In this paper, we focused on the generation of the shear wave using a dipole source in water. We first made a scaled model of a deep-tow seismic survey using solid material with a set of reflectors and an overlain water layer and conducted an exploration experiment as a feasibility study. For the model, we performed both an acoustic experiment as well as numerical simulations to see if the shear reflection could be generated by a source in water without any contact to the solid surface. As a result, we confirmed that shear waves are generated at the liquid-solid interface and are reflected at the interface of material heterogeneities even with a hydrophone streamer. Numerical simulation indicates that the amplitudes of the S-to-S or S-to-P reflected would be emphasized if we use horizontal seismic sensors on the liquid-solid interface. Our experiment has encouraged us to fabricate a mock-up of Marine Seismic Vibrator (MSV) to confirm seismic signal generation and to verify that the source could be distended to multi-pole setup for shear wave generator.