Joint Inversion of marine MT, Gravity and Seismic Data.

Abstract

Exploration of sub-basalt targets is difficult because the basalt units reflect and scatter seismic energy, masking the characteristics of the underlying structure. Electromagnetic soundings are less sensitive to the highly resistive basalt units but are strongly influenced by the characteristics of the over and underlying sedimentary structures. So electromagnetic soundings are a valuable compliment to seismic surveys in such areas. We have developed a joint interpretation scheme and inversion algorithm of seismic, MT (magneto-telluric) and gravity data that combines the information content in these data. While each method in itself is able to resolve only a part of the subsurface, we demonstrate that our joint inversion/interpretation technique allows us to identify the base of the basalt and yields information about the underlying sediment. Using synthetic data we demonstrate how the various data types contribute to our inversion/interpretation technique, and show how we recover the sub-basalt structure. We then apply this combined scheme on marine MT, satellite gravity and long-offset seismic data acquired along FLARE-10 profile. This work has been conducted under the EU funded SIMBA project and the FLARE-10 seismic data were made available to us by Amerada Hess