Talks will be given by
Fowler ‘A’ Award Winner
Dr Mark Swinbank (Durham University)
Galaxies Under the Cosmic Microscope: Resolving the Dynamics, Star-Formation and Chemistry of High-Redshift Galaxies
Keith Runcorn Thesis Prize Winner
Dr Sudipta Sarkar (GEOMAR - Helmholtz Centre for Ocean Research Kiel, Germany)
Seismic evidence for shallow gas-escape features associated with a retreating gas hydrate zone offshore west Svalbard
George Darwin Lecture
Professor Eline Tolstoy (University of Groningen)
Abstract for Dr Sudipta Sarkar, Seismic evidence for shallow gas-escape features associated with a retreating gas hydrate zone offshore west Svalbard:
Active gas venting occurs on the uppermost continental slope off west Svalbard, close to and upslope from the present-day intersection of the base of methane hydrate stability (BMHS) with the seabed in about 400 m water depth in the inter-fan region between the Kongsfjorden and Isfjorden cross-shelf troughs. Gas seeps mostly occur in the zone from which the predicted BMHS at the seabed has retreated over the recent past (1975–2008) as a consequence of a bottom-water temperature rise from 2º to 3º C. There is no evidence for a bottom simulating reflector (BSR as a proxy for BMHS) close to the gas seepage region, but a BSR is found downslope (depth ~600 m) of the seepage sites. Numerous gas pockets exist directly below the predicted BMHS. The scattered distribution of gas seeps indicates the role of lithological heterogeneity in focusing gas migration to the earlier sites of gas hydrate formation or release of gas once hydrate dissociated.
Key words: bottom-water warming; bright spots; gas hydrates; bottom simulating reflector; gas seeps; glacimarine strata
Biastoch, A., et al. (2011), Rising Arctic Ocean temperatures cause gas hydrate destabilization and ocean acidification, Geophys. Res. Lett., 38, L08602, doi:10.1029/2011GL047222.
Sarkar, S., C. Berndt, T. A. Minshull, G. K. Westbrook, D. Klaeschen, D. G. Masson, A. Chabert, and K. E. Thatcher (2012), Seismic evidence for shallow gas-escape features associated with a retreating gas hydrate zone offshore west Svalbard, J. Geophys. Res., 117, B09102, doi:10.1029/2011JB009126.
Westbrook, G. K., et al. (2009), Escape of methane gas from the seabed along the West Spitsbergen continental margin, Geophys. Res. Lett., 36, L15608, doi:10.1029/2009GL039191.