Tomographic analysis and geological context of a bottom simulating reflector on the South Shetland Margin (Antarctic Peninsula)

A seismic reflection tomographic analysis to identify spatial variations of wave velocity across a Bottom Simulating Reflector (BSR) on the South Shetland Margin, in the northern tip of the Antarctic Peninsula is presented. It is shown that conventional and continuous velocity spectra, as well as tomographic inversion of reflected arrivals, support the hypothesis that the strong reflector is due to the presence of a gas hydrate layer overlying a zone of free gas. A geological framework for the South Shetland Margin and a general overview of the relevance of gas hydrates in geological processes are presented as an introduction to the tomographic analysis. -from Authors