Oil on all these samples was analyzed at WHOI using comprehensive two-dimensional gas chromatography. The technique identifies the thousands of individual chemical compounds that comprise different oils from different reservoirs. The chemistry of the oil on the debris matched that of oil sampled directly from the broken pipe from the Macondo well above the Deepwater Horizon rig.
In addition, one piece of debris from the Chandeleur Islands retained a weathered red sticker that read "Cuming" with the numbers 75-1059 below it. Reddy found a company called Cuming Corporation in Avon, Mass., which manufactures syntactic foam flotation equipment for the oil and gas industry. He e-mailed photos of the specimen to the company, and within hours, a Cuming engineer confirmed from the serial number that the foam came from a buoyancy module from Deepwater Horizon.
"We realized that the foam and the oil were released into the environment at the same time," Reddy said. "So we had a unique tracer that was independent of the oil itself to chronicle how oil and debris drifted out from the spill site."
The scientists overlaid the locations where they found honeycomb debris on May 5 and 7 with daily forecasts produced by the National Oceanic and Atmospheric Administration (NOAA) of the trajectory of the spreading oil slick. NOAA used a model that incorporated currents and wind speeds, along with data from planes and satellites. On both days, the debris was about 6.2 miles ahead of the spreading slick.
The explanation, the scientists said, is the principle of leeway, a measure of how fast wind or waves push materials. The leeway for fresh oil is 3 to 3.3 percent, but the scientists suspected that "the protruding profile of the buoyant material" acted acting like a sail, allowing wind to drive it faster than and ahead of the floa
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Woods Hole Oceanographic Institution