1. Seafloor slumping in the South Caspian Sea: Evidence for massive gas hydrate dissociation during the late Pleistocene
Camelia C. Knapp, Christopher C. Amos, James H. Knapp, Department of Earth and Ocean Sciences, University of South Carolina
This research aims to interpret and analyze a large (640 km2), industry-quality, 3D multichannel seismic reflection dataset (3 s) and well-logs from the petroliferous South Caspian basin, offshore Azerbaijan, in order to clarify the origin, age, and areal extent of a large-scale late-Pleistocene zone of seafloor deformation and submarine slumping, the Absheron Allochthon (AA).These data are uniquely set to evaluate proposed mechanisms for late-Pleistocene large-scale submarine slope failure, and favor a relationship with the dissociation of underlying gas hydrates.
Since the inland Caspian Sea is affected by sea level fluctuations at much shorter time scales and much larger amplitudes than the world’s oceans, the premise is that climate-induced changes in sea level were responsible for large scale slope failure and seabed deformation through massive dissociation of buried gas hydrates during the sea level lowstands in the late-Pleistocene. This region may become a natural laboratory to study the relationship between the gas hydrate dissociation and seafloor deformation, and may be further used as a proxy for similar processes in the world’s oceans.
TOP: Distribution of AA facies. BOTTOM: Chaotic facies component (red) and continuous facies component (green) of the AA, separated by the transitional zone (yellow). An earlier stage of slumping is bounded by dark blue and orange horizons. The seafloor is denoted by the uppermost red horizon, and the Absheron series is denoted by the lowermost red horizon. Note the relatively undisturbed strata immediately above and beneath the AA. Seismic profile location shown atop seafloor bathymetry.