Tuesday, May 04, 2010

What was the largest *accidental* oil spill in history?

Ixtoc I oil well blowoutImage via Wikipedia
US Gulf Coast residents are bracing for the environmental impact of the Deepwater Horizon oil spill, which by some estimates has to date dumped some 40,000 tonnes of crude oil into the Gulf of Mexico as a result of an oil rig explosion on April 20, 2010. While the ecological (and political) cost of this disaster has yet to be tallied, the sad truth is that the Deepwater Horizon spill doesn't even crack the Top 10 list of worst oil spills ever.

Sadder still, the single worst oil spill in history was intentional. On Jan. 21, 1991, Iraqi forces retreating during the first Gulf War intentionally opened transfer valves at Kuwait's Sea Island oil tanker terminal, dumping over one million tonnes of crude oil into the Persian Gulf in a failed attempt to prevent US Marine forces from landing in the area. Along with oil spilled from damaged tankers and pipelines, the Gulf War oil spill was roughly three times larger than the largest accidental oil spill in history.

What was the largest accidental oil spill in history?

The Ixtoc I oil spill, which began on June 3, 1979, dumped over 450,000 tonnes of crude oil into the Gulf of Mexico. The spill was the result of a malfunction aboard a drilling rig in the Bay of Campeche, some 70 miles of the coast of Mexico and 600 miles south of Texas. The drill rig suffered a loss of counterpressure and an uncontrolled blowout of crude oil from the underwater well. The blowout caused the oil rig to catch fire and eventually collapse. The Ixtoc I well leaked oil for nine months before Pemex, Mexico's national oil company, was able to cap the well on March 23, 1980.

As it stands right now, the Ixtoc I oil spill is an order of magnitude larger than the currently horrific Deepwater Horizon oil spill. Estimates vary wildly as to how much oil is leaking per day from the Deepwater Horizon well, but if it takes months to cap the well -- as it did in the Ixtoc spill -- then Deepwater Horizon may well displace the infamous Exxon Valdez spill as the largest in US history. By some accounts, it already has.

By any measure that's a tragedy, and far from the truly trivial.