Origin and distribution of methane and methane hydrates in the Black Sea - Cruise No. M84/2 - February 26 - April 02, 2011 - Istanbul (Turkey) - Istanbul (Turkey) (English)

The aim of the cruise was to investigate the gas hydrate distribution in sediments of the Black Sea by using several coring technics. Drill sites with the portable drilling system MeBo should extend the normal coverage of the dynamic autoclave piston corer (DAPC) and gravity cores into deeper sediments down to 30-50 m below seafloor. In addition to the coring activities the newly installed EM122 and the PARASOUND system should be used for gas emissions to the water column. The MeBo system was deployed at four sites and drilled altogether 52 m sediments and massive gas hydrates at Pechori Mound. Unfortunately the drilling operation with MeBo had to be canceled after failure of the hydraulic system. In total 10 DAPC, 46 gravity cores and 21 mini corer samplings have been successfully performed. PARASOUND and the multibeam (EM122) were recorded for 17 days and 23 hours in Ukrainian, Turkish and Georgian waters in order to measure gas emissions from the seafloor by flare imaging. EM122 surveys have been extremely useful in both the western (Eregli) and eastern (Ordu Ridge) areas of the Turkish continental margin, where backscatter analyses guided us to the areas of shallow gas hydrates. In Georgia selected areas with SAR satellite-imaged oil slicks have been investigated for their gas flares and sediment composition. In two areas on the western and eastern Kulevi Ridge oil-rich sediments were sampled in association with the gas flares. In Ukraine Kerch flare and Helgoland mud volcano have been very successfully investigated for their temperature gradients and their gas hydrate presence in near-surface sediments.