Abstract
This study was performed to investigate gas formation and gas saturation conditions related to acoustic turbidity in shallow (∼40 m deep) marine basins. The Arkona Basin, Baltic Sea, with its organic-rich fine-grained surface sediment provides an ideal “Natural Laboratory” to characterise free gas using seismic, geoacoustic, and geochemical methods. The area of acoustic turbidity covers about 1500 km 2 of the central Arkona Basin, corresponding to areas where organic-rich post-glacial sediments exceed 4–6 m in thickness. The highest concentration of pore water methane (7660 μmol L −1), found in areas of high acoustic turbidity, was near the calculated lower limit of methane solubility for the measured in situ temperature, salinity, and pressure. Pore water methane concentration decreased to near 4 μmol L −1 in areas outside of the zone of high acoustic turbidity. Stable carbon (−70.7‰ to −92.3‰ PDB) and hydrogen (−124‰ to −185‰ SMOW) isotope values of methane indicate that methane is predominantly formed by microbial CO 2 reduction in Arkona Basin surface sediments and rules out significant contributions of other sources.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
