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Schlagwörter:
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Zusammenfassung:
The Ligurian Sea is located in a complex tectonic area, at the Western Alps – Northern Apennines junction. Little is known about the structure of the basin and the continuation of the Alpine orogen offshore. The Ligurian Sea formed as a back-arc basin related to the retreat of the Apennine subduction zone. During extension, the Corsica-Sardinia block drifted eastwards, rotating counter-clockwise to its current position. The nature of the crust in the basin, whether atypical oceanic crust, thinned continental crust, or even exhumed mantle with thick sediment cover, is still a topic of debate. If oceanic crust was formed, its extent is poorly mapped.
Moreover, seismic and geodetic data show that the basin is now under compression. The area is known to have hosted large, tsunamigenic earthquakes in the past, however, its location boarding France, Monaco, and Italy, and climate mean that the coastline is densely populated despite the risk. Understanding the nature of the tectonics in the basin can therefore help assess the seismic hazard of the area.
In this project we use P-wave travel time tomography to generate a 3D velocity model of a section of the Gulf of Lion into the Ligurian Sea. This project is part of the DFG Priority Program “Mountain Building Processes in Four Dimensions (4DMB)”. We use data from the LOBSTER-AlpArray OBS as well as from the 2006 SARDINIA Experiment. With FMTOMO we incorporate reflected and refracted rays as well as water multiples which in some cases improves the ray coverage.
