Tuesday, December 14, 2010
Deepwater Horizon Blowout - Existence of Undersea Plumes of Oil
The environmental catastrophe caused by the blowout of the Deepwater Horizon at the Macondo well site resulted in the largest offshore oil spill in history. Although much of the surface oil contamination has been significantly mitigated, there remains an issue regarding the existence of undersea hydrocarbon plumes.
These plumes have been tracked by Dr. Richard Camilli and his colleagues from the department of Applied Ocean Physics and Engineering at the Woods Hole Oceanographic Institution. As a result of the blowout, more than 4 million barrels of oil were released into the Gulf of Mexico. Since the source of the spill was some 1500 meters beneath the surface, this resulted in the formation of undersea plumes of oil. On account of the complex variables that are involved in plume formation – the interplay of gas and oil in multiphase flow and the solubility of each of the constituents in the complex mixture - , it is exceedingly difficult to derive models that can reliably predict the behavior of hydrocarbons under such conditions.
In spite of the daunting problems associated with this catastrophe, the investigators were able to detect and measure the hydrocarbon plumes. They discovered the presence of a continuous plume of oil more than 35 kilometers in length at an approximate depth of 1100 meters. This plume persisted for months without signs of significant biodegradation.
Further studies by other investigators, however, have shown that the presence of the plume stimulated the growth of bacteria that are known to degrade hydrocarbons. The encouraging aspect of their findings is that, “the potential exists for intrinsic bioremediation of the oil plume in the deep-water column without substantial oxygen drawdown.”
The existence of undersea hydrocarbon plumes in the Gulf of Mexico has inspired scientific investigators to study their properties. The results of their work may lead to strategies designed to counter the ill effects of similar human catastrophes should they happen in the future.