Monday, March 31, 2014

Deep-C Researchers On-Site at Oil Spill in Galveston Bay

Thick, tar-like oil collected at Seawolf Park in Galveston Bay.
(Photo credit: Robert Nelson, WHOI)
There is an old adage that soldiers are always preparing to fight the last war. So it’s not a stretch to think that future spills in the Gulf of Mexico will be similar to the Deepwater Horizon (DwH) disaster. But a recent spill in Galveston Bay (near Texas City, Texas) proves otherwise, and we are collecting samples in our continued quest to understand the fate and transport of oil in the Gulf and elsewhere. 

On March 22, 2014, a container ship, the M/V Summer Wind, collided with the oil barge, Kirby 27706. One of the starboard tanks on the Kirby was ruptured and released 168,000 gallons of fuel oil; the Summer Wind did not leak any oil. The Houston Ship Channel and Intracoastal Waterway were closed for three days. Over the course of the next week a large plume of oil that washed out of the channel into the Gulf of Mexico drifted south to impact shorelines up to 200 miles away on Matagorda Island and Mustang Island. 

The Kirby spill could not be any more different than the DwH that spilled an estimated 160 million gallons of light, sweet crude oil nearly four years ago in the Gulf of Mexico at the bottom of the ocean floor from an uncontrolled well for 87 days. The Kirby spilled much less oil than the DwH but it was a thick, black viscous product called an intermediate fuel oil. 

WHOI’s Bob Swarthout collecting oil over 50 miles
from the spill location near Freeport, Texas.
(Photo credit:  Robert Nelson, WHOI)
Fuel oils are prepared from high-viscosity refinery residues remaining after crude-oil distillation (think bottom of the barrel) that are blended with low viscosity distillates, such as kerosene, to enable transport and use. Because the residues from crude oils and the distillate can vary, there is no standard fuel oil. While this variability provides some challenges to the oil spill community, spills of fuel oils are often called “dirty bathtub” spills as they leave a ring of oil along coastlines. 

To understand how the oil changes or “weathers” we have begun a sampling campaign along the beaches and shores of Galveston Bay and the impacted Gulf of Mexico coastline. We are particularly keen to observe if any massive changes due to oxidation, similar to what we saw following the DwH, is occurring. And we can compare it to three other fuel/oil spills we are investigating: Prestige (2002; Spain); Bouchard 120 (2003; Buzzards Bay, MA); and Cosco Busan (2007; San Francisco Bay, CA). 

Me (Bob Nelson) collecting sticky, tar-like oil from an
impacted marsh. (Photo credit:  Bob Swarthout, WHOI)
During our initial trip to the region, we collected scrapings of oil from marine debris and oil coated marsh grasses near the site of the spill. At Seawolf Park, with a World War II era destroyer as a backdrop, we sampled large amounts of pooled oil from divots in concrete rip-wrack. We also drove south along the coast to find oil that had been exposed to different weathering conditions. Numerous response crews working along the coast showed us that oil was washing up for tens of miles along the Gulf coast, and we collected samples of apparently fresh oil along approximately 50 miles of coastline between Galveston and Freeport. 

We have a lot more work to do before we will have any answers. But first, we have to get the samples back to our laboratory (we also plan to share the samples with the Florida State University National High Magnetic Field Lab and with Christoph Aeppli at the Bigelow Lab).  We will “fingerprint” the samples to confirm the samples share the same source and then examine “weathering” patterns. 
Galveston Marine Corp Base, March 31, 2014 (Photo credit: Robert Nelson, WHOI)

Oiled rip-wrack at Seawolf Park with trapped pockets of oil.
(Photo credit: Robert Nelson, WHOI)

Posted by: 

Robert Nelson, Research Specialist
Woods Hole Oceanographic Institution 

Bob Swarthout, Post-Doc
Woods Hole Oceanographic Institution

No comments:

Post a Comment