MARIA S. MERIAN MSM71

The aim of cruise MSM71 LOBSTER (Ligurian Ocean Bottom Seismology and Tectonics Research) is twofold: 1) to conduct a detailed amphibious seismic refraction survey of the Ligurian basin transition from the oceanic to the continental domain, and 2) to recover a network of French/German ocean bottom seismometers (OBS) in the framework of AlpArray and the German SPP 2017 ‚Mountain Building Processes in 4D’.
AlpArray is a European initiative with the aim to deploy several hundred closely spaced broadband seismometers that cover the entire Alpine orogen to provide state-of-the-art imaging of subsurface structures. The offshore component of AlpArray involves the deployment of 29 broadband stations from France/Germany in the Ligurian Sea. This deployment took place in June 2017 using the French RV PourquoiPas? as platform. In order to share ship-related costs between the two nations, recovery will be conducted using RV Maria S. Merian. OBS recordings of teleseismic events will be essential to define subsurface structures at the transition from the Western Alps to the Apennines and improve our understanding of the 3D-geometry of the system and its kinematics. In addition, the two planned active on-offshore wide-angle transect of 150 nm each will unravel the upper structure of the Ligurian Basin at crustal scale resolution in particular the ocean-continent boundary at the Alps-Apennines junction which is poorly defined due to the lack of modern refraction data. Short-period OBS will be deployed along the two transects.