Tomographic and AVO analyses of Bottom Simulating Reflectors (BSR) on real data

Bottom Simulating Reflector (BSR) is a characteristic seismic horizon, appearing on marine reflection profile, which marks the pressure- and temperature-dependent base of the methane-hydrate stability field. Although the resource potential of marine gas hydrates is currently unknown, they continue to attract the attention of the scientific community because of their implication in geological evolution of continental margins, the possibility of related presence of enormous free gas reservoirs, and their possible impact on the environment. In this paper we describe the application of different tools, as AVO, reflection tomography and pre-stack depth migration, in order to analyze the physical properties of BSR observed in two different real data sets. The tint dataset pertains to a marine line acquired in the South Shetland margin and the second one is relative to offshore South Chile. In both cases the results of the seismic study are consistent with the presence of a consolidated gashydrate layer which overlies a porous level saturated with free gas.