By Janet Raloff
In a part of the world accustomed to the annual ritual of hurricane season, anticipating the landfall of oil from the Deepwater Horizon drilling platform that sank in the Gulf of Mexico April 22 has an eerie familiarity.
But unlike hurricane season, no one knows when this most recent threat to the marshes and estuaries of the Gulf Coast will end. Oil continues to gush unchecked from the seafloor site of the wrecked rig, some 40 miles off the Louisiana coast. It’s not clear how soon the well can be successfully capped, nor the magnitude of environmental threat posed by the river of oil that it’s spewing.
Best estimates indicate the well, which tapped a reservoir 13,000 feet below the seafloor, is pumping another 5,000 barrels — 210,000 gallons — of oil into Gulf waters daily. Several attempts to engage a shutoff valve at the seafloor have already failed. So within a week, British Petroleum, which had been leasing the Deepwater Horizon, hopes to effect a temporary fix: placement of a 125-ton containment dome over the largest source of oil (there are now several) from the wrecked rig.