A new coupled circulation/oil spill model based on the DieCAST ocean circulation model and the oil spill model has been applied to the Black Sea to address the transport, fate and 3-D structure of the oil plume resulting from a representative hypothetical accidental deepwater blowout. The model realistically simulates many of the dominant mesoscale structures. Based on the Lagrangian tracking method, describes various scenarios of hypothetical deepsea oil blowouts in regions of the Black Sea prospective for drilling and development are simulated and discussed as to their structure, transport and likelihood of coastal contamination.
The Black Sea, presently faces strong ecological disequilibria owing to eutrophication and pollution arising from many contaminants injected principally from rivers discharging into the basin, atmospheric deposition, direct discharges from point and non-point coastal sources and occasional accidents at sea. Major contaminants include oil residues, pesticides, hydrocarbons, nutrients and heavy metals. Accidental oil spills during the oil transportation pose a very high level of risk for the marine environment and coastline (Stoyanov et al., 1999; Korotenko et al., 2010; Mityagina and Lavrova, 2012) as the Black Sea is essentially a closed basin and thus very sensitive to continued high fluxes of contamination. In this connection, a serious threat for the Black Sea environment is caused nowadays by exploration and development of deepwater oil and gas resources.
That the Black Sea bears major resources of higher hydrocarbons is known for many years (e.g. Robinson et al., 1996 and references therein). Seepage of oil at the seafloor of the Black Sea was noted during a number of research cruises in 2000s. At many sites on the shelf of the seaside countries of the Black Sea oil and gas seep structures were discovered, where hydrocarbons are emanating at the seafloor and gravity coring revealed the presence of oil in the bottom Fig.1 presents the Black Sea bottom topography and a composite (obtained in different cruises) map of areas, where the presence gas and oil was revealed (Robinson et al., 1996; Egorov et al., 2003; Laverov 2003; Ergün et al., 2002). Gas and oil seeps are associated with leakage from gas-oil reservoirs and from gas hydrates; consequently, they occur in all the oceanic environments: coastal environments of deposition (bays, estuaries etc.); major deltas; hydrocarbon-bearing sedimentary basins on the continental shelf and slope etc. (Egorov et al, 2003).