Swath-seismic mapping of European continental margins

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We propose the development of "swath-seismics" using 9 parallel 9-channel streamers as an antenna to map out sub-surface geology at continental margins. As the width of each swath is approximately twice the water depth, the method can cover areas, several orders of magnitude more quickly than conventional mapping with grids of 2-D seismic lines or multistreamer near-vertical seismics. Targets include tilted fault blocks, serpentinite ridges, the tops of lava flows, the top of the giant Gibraltar Olistostrome and the Bottom Simulating Reflector. The BSR is associated gas, which occurs at the base of gas hydrates. The method should also be able to image and map fields of diapirs and mud volcanoes. The versatility of the method gives it widerspread and diverse application to European continental margins and their conjugates. Mapping of basement structure is particulary relevant for studies of rifting processes at both non-volcanic and volcanic continental margins. Mapping of BSRs and of mud volcanoes and other seeps and vents are essential for studying the fluid flow regime of the margin, and its linkages with the thermal regime, slope stability, neotectonics and gas hydrates. The proposal, thus, has relevance for all three main themes of the EUROMARGINS call for proposals.