Researchers Respond to Gulf Oil Spill with Several Innovative Solutions
By GEORGE FOULSHAM
RESEARCH AND ANALYSIS by UCSB scientists were regularly featured in national and international press coverage in the aftermath of one of the world’s worst environmental disasters — the Deepwater Horizon oil spill in the Gulf of Mexico. The accident provided researchers from earth science, mechanical engineering and the Marine Science Institute an opportunity to turn the spill site into a remote laboratory.
Playing prominent roles in the post-spill research were David Valentine, a geochemist and professor of earth science; Ira Leifer, a researcher with the Marine Science Institute; and Igor Mezic, a professor of mechanical engineering.
“We were fortunate to have the expertise and opportunity to get to the heart of this national disaster and to contribute meaningfully to understanding what was happening in the deep ocean during the spill,” Valentine said. “As a scholar, it is rare that your intellectual domain comes so abruptly to the forefront of the national consciousness. Circumstances aside, I feel that it reflects well on our country’s scientific and educational systems that we foster such expertise.”
Valentine participated in several research vessel cruises in the Gulf of Mexico to study the impact of hydrocarbon plumes escaping from the deep-water ocean spill. Valentine and Texas A&M’s John Kessler led scientists from both institutions on an expedition less than two months after the spill to study the behavior of methane and other natural gases. The results of that study were published online in the journal Science.
Among their many findings, the scientists determined that methane gas, the most abundant compound spilled by Deepwater Horizon, was initially consumed very slowly by bacteria, but the rate increased as other gases were depleted.
“Because the Deepwater Horizon rig accident occurred almost a mile deep, the slow migration of petroleum from that depth allowed time for dissolution of volatile hydrocarbons such as methane, ethane, propane, and butane,” Valentine said. “Had it occurred in shallower water, these gases would have certainly escaped into the atmosphere. This gas trapping will go down as one of the distinguishing hallmarks of a deep oil spill.”
Ira Leifer was a key member of two government-appointed scientific panels charged with determining the impact of the spill.
The scientists employed multiple methods to study the spill, including airborne remote sensing with NASA’s Airborne Visible/Infrared Imaging Spectrometer, video of the oil emanating from the seabed, and satellite data analysis. Leifer was chief mission coordinating scientist for the NASA effort for airborne remote sensing of the oil spill. He was also one of the experts on the Flow Rate Technical Group, which worked on studying the seabed emissions.
Leifer was outspoken in his criticism of the flow-rate estimates released by the government, saying that the numbers released by the White House were a range of “lower bound” estimates from scientists. In reality, he said, the ongoing data analysis showed that the numbers were significantly higher. His calls for action prompted BP to provide better-quality video for analysis and resulted in a revised estimate of the amount of oil spilling into the Gulf of Mexico.
Leifer, an expert on methane and hydrocarbon plumes in the oceans, became a regular commentator on national television news programs throughout the spill, and he continues to be quoted by reporters all over the world.
In a paper published online in the journal Science, Igor Mezic detailed how he and his colleagues were able to successfully forecast where and when oil spilled from the Deepwater Horizon disaster would wash ashore.
“We predicted where the oil was going to go,” Mezic said. “We were able to do three-day predictions pretty accurately.”
Meiz, working with Sophie Loire, a postdoctoral fellow, and colleagues at the software development company Aimdyn, Inc., in Santa Barbara, was able to predict that the oil would wash ashore in parts of the Mississippi Delta, and then on beaches near Pensacola, Fla. They also correctly forecasted that the spill would move farther east toward Panama City Beach in Florida.
Their approach was based on computations that describe how slicks of oil tend to be stretched into filaments by water movement. They also incorporated forecasts of sea surface conditions from a U.S. Navy model. Their predictions were shared with the U.S. Coast Guard.