1. En-Route Surveys :

acoustic survey of the whole Marmara Sea to detect systematically fluid and gas escapes using the EM-300 of R/V Le Suroit (Fig. 5a).

High-resolution acoustic and microbathymetric surveys at each site using the AUV-Asterx of Ifremer to map finely (resolution < 1 m) the gas vents and the deformation near the fault zone. The AUV (Fig. 5b) will be deployed from R/V Le Suroit.

 high-resolution seismic surveys to image the fluid conduits in the upper (1 km) sediment layer. These surveys will be conducted also using R/V Piri Reis and seismic facilities available at DEU-Institute of Marine Technology (section 4).

2. Instrument deployments :

The following instruments (Fig. 6, 7, 8) will be deployed at each site (see site description, Fig. 4) : piezometers, OBS, flowmeters, SN-4, in-situ chemical sensors (including osmo-samplers), CTD probes. These instruments are already available at IFREMER, INGV and Scripps Institution of Oceanography. With such monitoring we will be able to quantify the temporal and spatial relations between fluid expulsion, fluid chemistry and seismic activity (see instrument description in section 3). For deployment and recovery, the partners’ naval facilities will be used : R/V Le Suroit (Ifremer), R/V Urania (ISMAR/CNR), R/V Piri Reis (DEU) and R/V Sismik-1 (ITU). There will be 3 or 4 sites, funds permitting.