Is it true that the blown-out oil well in the Gulf of Mexico is a bigger and worse leak than the Exxon Valdez disaster?

Answer 1

Sometimes, simple questions do not lead to simple answers.

More oil spilled- Yes. Areally larger - difficult to say. Worse to the environment- too early to tell. Environmental damage is complicated. While I hate to complicate good headlines with minor technical details, but let me suggest that comparing Exxon Valdez to BP spill is difficult. Different marine and coastal environments, different type of spill, different clean up containment and clean up measures.

Any oil spill will expand with the wind and currents, and undergo mechanical dispersion, with chemical and biological changes to its structure and makeup. Assessment of the environmental impacts of the weathered oil, distant from the foci can be subjective.

Has more oil spilled out into the Gulf of Mexico at this point in time than spilled during the Exxon- Valdez disaster? The best answer is yes, if you accept the Task Force estimated Macondo flow rates of 12,000 to 19,000 barrels/day or 0.504 to 0.798 million gallons per day. Perhaps you've seen the headline that more than a million gallons is flowing from the well. It is actually a bit less than a million gallons per day on the upper end of the range. So, given the well has been flowing for around 40 days, the oil spilled in the gulf to present (May 30) is approximately 20 to 32 million gallons. Exxon valdez accident in 1989 spilled 11 million gallons.

The volume issue is complicated by the fact that oil is being recovered with skimmers, which will continue after the well has been capped. The insertion tube and control burns reduce the amount of oil at surface. The volume at the surface is being diminished everyday by evaporation of the lighter hydrocarbons and dissolving in the sea water aided by dispersants. Evaporation did occur with Exxon-Valdez oil, but it was a heavier crude and seawater was colder. So is the net oil volume at the surface for the BP spill more than Exxon Valdez? I don't have an answer.

Is the areal extent larger? I know for the Exxon-Valdez spill, the affected area became a very controversial issue- particularly in the courts. I expect that the areal extent of the BP spill will be equally controversial, as it becomes more difficult to track the individual streams with low concentrations of oil (or tar balls).

Which spill has done the most environmental damage? I think it's too early to tell. Oil has invaded environmentally sensitive areas but at present, it is fairly localized. The BP spill is still going as of May 30. There will be some recovery of the ecosystem, as was the case in the Gulf War spill, Ixtoc, and the Exxon Valdez.

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