Hotspot dominated rifting: Volcanic island evolution and collateral geo-hazards resulting from cascading geodynamic processes - The instance of Sao Miguel (south-eastern Terceira Rift, Azores)

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Sao Miguel is the biggest and most populated volcanic island of the Azores. The island is located on the south-eastern Terceira Rift, one of the plate-boundary hotspots of Eurasia. However, little is known about the structural evolution of the Sao Miguel section of the Terceira rift, nor about collateral geo-hazards. Based on a preliminary interpretation of an intense multi-parameter geophysical survey with RV Meteor in 2009 we intend to test, among others, the following hypotheses: 1. The sigmoidally shaped basin system in the vicinity of Sao Miguel represents a volcanically active leaky transform fault that links two extensional segments of rift. 2. Geo-risks result from cascading geodynamic processes like mantle diapirism (hotspot) and plate tectonics, earthquakes, plutonism and volcanism, than mass wasting, tsunami generation and escape of poisonous gas. Our project strives for a comprehensive understanding of the partly consecutive earth processes by imaging the three dimensional structure of the south-eastern Terceira Rift and and the mapping of resulting structures by being the first to combine under the same project a variety of data sources: wide-angle reflection / refraction seismic data, gravity, magnetics, multi-channel seismics, muti-beam and parametric sediment echosounding. The acting processes will be reconstructed by a “bottom-up” approach, starting with the analysis of the crust-mantle boundary and ending with the seafloor morphostructure.