The Deepwater Horizon explosion caused an environmental crisis much larger than just an oil spill.
A massive underwater methane plume flowed out of the open well and researchers at Yale and Texas A&M University have been collaborating to track the potent greenhouse gas’ dispersal throughout the Gulf of Mexico. The gas is a significant contributor to global warming. The environmental ramifications will become apparent over decades rather than months, said John Kessler, assistant oceanography professor at Texas A&M University, and his research partner, School of Forestry and Environmental Studies professor Peter Raymond. So the informed citizen should not predict an immediate apocalypse, the researchers said.
Particle by particle, methane accounted for far more of the fluid that gushed for 83 days out of the uncapped well than any other substance, Kessler said. While the oil remained visible to the human eye, the methane dissolved into 500 square kilometers of ocean water, Kessler said.
But unlike the oil, the methane cannot be cleaned up so easily.
Methane is currently both dissolving into the atmosphere — increasing the greenhouse gas’ atmospheric concentration — and being consumed by oceanic microorganisms, which could create an aquatic dead zone, he explained.
METHANE IN THE WATER
During the spill, the US Department of Energy, in conjunction with BP, measured the ratio of natural gas to oil within the fluid that rose up from the uncapped well. Kessler used this research to calculate the volume of methane expulsed into the ocean each day, which he said was significant.
Kessler equated that amount to the volume of methane seeping up from the floor of the Black Sea — considered the greatest methane leak site on Earth — during the same period of time. The Deepwater Horizon oil spill could mimic this natural phenomenon because it occurred both far beneath the ocean surface and over several months, he said.
“We thought of it as a natural lab,” Kessler said. “No one would allow us to dump this much natural gas into the ocean.”
Since their funders, the National Science Foundation, exclusively support hypothesis-driven science, Kessler and his team could not engage in acts of conservation during the spill, only gather empirical data, he said.
But Kessler said he would not have signed onto a project that was solely relief-focused.
“Not to poo-poo at all on monitoring efforts,” he said. “But personally, if I were just doing monitoring, I probably wouldn’t be interested.”
Kessler spent his days in 12-hour shifts dipping for samples of the water 1500 meters beneath his ship. He and his team then tested the samples for methane and other hydrocarbons.
The team motored across the gulf in order to obtain a range of geographically diverse data. They even tested at ground zero.
“We got within 500 meters of [the oil rig],” Kessler said, explaining that the well’s capping efforts included burning off natural gas producing a five-story flare. “It was like Armageddon.”
While the environmental school director of communications David Defusco said that the methane plume has gone largely unnoticed by the press, news sources such as MSNBC, NBC and CNN have reported that popular science followers are concerned by the volatility of the Methane Situation.
Some followers adhere to a theory which claims that past explosions of methane from the Earth’s crust caused mass extinctions, perhaps even that of the dinosaurs, according to MSNBC.
But Raymond said this idea belongs in the realm of popular science literature.
Kessler added that during the spill, concerned Gulf coast residents called him to ask if they should sell their homes immediately.
“By the tenth call, you’re like, what the hell is going on here?” he said.
Kessler said he is hesitant to predict doomsday and instead is focusing on the methane plume’s current behavior.
His current hypotheses attempt to quantify how the Deepwater Horizon methane is distributing itself between the atmosphere, the ocean, and microrganismal consumption. So far, he said he has observed oxygen depletion upwards of 20 percent. Raymond said he thinks this is relatively low, considering the outrageous projections of the early summer.
But it will not be clear for many — perhaps even 400 — years how methane will affect the aquatic environment, Raymond said.
“I think we’re kind of holding our breath,” he said.
The Deepwater Horizon oil well was capped on Sept. 19.