Far beneath the surface, US oil spill cleanup unfolds
While emergency teams are racing to protect Louisiana's fragile coastlines, the tough business of shutting off the oil spewing into the Gulf of Mexico is taking place far below the ocean surface.world Updated: May 02, 2010 08:35 IST
While emergency teams are racing to protect Louisiana's fragile coastlines, the tough business of shutting off the oil spewing into the Gulf of Mexico is taking place far below the ocean surface.
Nearly a mile (1,500 meters) down on the seabed, six robotic submarines were locked in a race against time to activate a 450-tonne valve to cap a fractured oil well from the sunken Deepwater Horizon rig.
British oil giant BP, which operated the platform before it exploded, caught fire and sank last week, has turned to other futuristic techniques, like building a giant containment dome to avert an environmental disaster of epic proportions.
With researchers warning the slick has tripled to cover an area the size of Puerto Rico, BP began drilling a relief well Saturday, a process that could take up to three months.
Officials are also testing and evaluating the company's plans to use chemical dispersants underwater to limit the impact of the broken well, which is spewing 200,000 gallons of oil into gulf waters each day, in a massive spill that could be seen from space.
Thousands of federal, state and private sector responders have descended upon the Gulf Coast for the unprecedented cleanup operation, with a flotilla of skimmers, tugs, barges and recovery vessels tasked with mopping up the oily mess.
But the hundreds of thousands of feet of inflatable oil boom and various skimming systems have so far not prevented the waters from turning black and a huge oily pool from inching toward the coastline.
Coast Guard Commandant Admiral Thad Allen, who is leading the response effort, noted that spill mitigation efforts have been hampered by the sheer logistical challenge of stanching the leak at the deep underwater well.
"One of the real problems we are having working in that area is what I would call the tyranny of distance and the tyranny of depth," he said.
Allen acknowledged it was "somewhat of a challenge" to operate at a depth of 1,500 meters (5,000 feet) the remotely controlled subs that have yet to succeed in activating a valve, known as a blowout preventer, by pumping it full of hydraulic fluid.
He warned that other options under consideration would be riskier, as Coast Guard officials expressed fears of a worst-case scenario where the well would turn into an unchecked gusher shooting out millions of gallons of oil each day -- 10 times greater than current estimates.
With the robotic submarines yielding little progress and the sheer amount of time required to drill a relief well, the dome could prove to be a crucial solution in mitigating the disaster.
The exact dimensions and design of the dome were still being worked out, but officials said it would be similar to welded steel containment structures called cofferdams that are already used in oil rig construction.
And time is of the essence. At the current estimated rate of leakage, it would take less than eight weeks for the spill to surpass the 11 million gallons of oil that poured from the grounded Exxon Valdez tanker in Alaska in 1989.
Although only a thin sheen of oil has reached the coast, Allen admitted the adverse weather conditions meant a major shore impact of crude was inevitable.
"There's enough oil out there, I think it's logical to assume that it will impact the shoreline. The question is when and where," he said.
It could take decades for the environment to recover, according to Greenpeace researcher Mark Floegel, who said waves were simply washing over the booms deployed to prevent the spill from reaching the coastline, in a region accounting for over 40 percent of America's ecologically fragile wetlands.