Methane levels in the ocean near the site of the BP oil spill are “astonishingly high”, according to some U.S. scientists. Last week, the scientists returned from 10-day research expedition in the Gulf of Mexico close to where the Deepwater Horizon oil rig exploded and eventually sunk more than 60 days ago.
The April 20 explosion on the Deepwater Horizon killed 11 men and spawned the worst oil spill in U.S. history. Since then, oil has been gushing into the Gulf at a rate of as much as 60,000 barrels a day, according to U.S. government estimates.
Methane is a colorless, odorless gas that is a major component in natural gas. It is also highly flammable. A bubble of methane is believed to have ignited the Deepwater Horizon explosion.
John Kessler of Texas A&M University in College Station, one of the scientists on the research expedition, said last week that methane in deep-ocean waters (below 1,000 feet) near the oil spill are 10,000 to 100,000 times higher than normal. At times, the team measured methane levels that were 1 million times above normal.
According to Reuters, the team took measurements of both surface and deep water within a 5-mile radius of the leaking well. Kessler characterized the leak as “the most vigorous methane eruption in modern human history,”
The team of 12 scientists from Texas A&M, Texas A&M Galveston and The University of California, Santa Barbara, discovered that the methane, which makes up 40 percent of the substances coming from the well, is staying in the deep waters and not escaping into the atmosphere.
Kessler said the amount of methane seen was enough to potentially deplete oxygen and create a dead zone in the Gulf. High concentrations of methane can encourage the growth of microbes that consume oxygen needed by marine life.
“At some locations, we saw depletions of up to 30 percent of oxygen based on its natural concentration in the waters. At other places, we saw no depletion of oxygen in the waters. We need to determine why that is,” Kessler said.
Though oxygen depletion hasn’t reached a critical level yet, Kessler said he feared what it might look like “two months down the road, six months down the road, two years down the road?”