Possible evidence for a relationship between gas hydrate dissociation and submarine slope failure in the Danube deep-sea fan, Black Sea

Badhani, Shray, Bialas, Jörg, Berndt, Christian, Klaucke, Ingo and Zander, Timo (2016) Possible evidence for a relationship between gas hydrate dissociation and submarine slope failure in the Danube deep-sea fan, Black Sea [Poster] In: 76. Jahrestagung der Deutschen Geophysikalischen Gesellschaft, 14.-17.03.2016, Münster, Germany.

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Abstract

Nearly 110 km of high-resolution multichannel seismic data from the Romanian Black Sea
reveal slope failures and paleo canyons of the Danube deep-sea fan. The new data allow
detailed investigation of a submarine landslide identified during a regional seismic and
multibeam bathymetric survey. The landslide scar has a dimension of 3 x 2.5 km and covers an
area of about 8 km². The volume of the mobilized material is estimated to approximately 0.36
km³. Based on average sedimentation rates in the Danube deep-sea fan, age of the landslide is
estimated to be around 12 ka. The absence of deposits at the foot of the landslide and the
vicinity of the paleo canyon suggest that the material removed during the slide event was
drained through the paleo canyon. We observe an upward bending bottom simulating reflector
(BSR) beneath and active gas expulsion from the seafloor encircling the landslide scar. The
water depth of the slide area correlates with the upper limit of hydrate stability. Modeling the
base of the gas hydrate stability zone (BGHSZ) for the paleo-water conditions during the last
glacial maximum (LGM) reveals an upward bending trend. The modeled BGHSZ for LGM crops
out in the vicinity of the headwall of the landslide whereas the present day BSR crops out at the
foot of the failed area. Therefore, we propose that warming of the Black Sea might have caused dissociation of gas hydrates resulting in building increased sediment pore pressure, possibly
triggering the landslide identified in our data.

Document Type: Conference or Workshop Item (Poster)
Research affiliation: OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-GDY Marine Geodynamics
Date Deposited: 22 Mar 2016 08:31
Last Modified: 05 Apr 2016 08:00
URI: http://eprints.uni-kiel.de/id/eprint/31904

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