Gulf Oil Spill Could Remain Threat for Years
|A trawler helps clean up oil off Louisiana's coast|
Only a fraction of the oil coming out of the Gulf gusher is visible on the surface. Much of it remains suspended in the depths of the Gulf, or has sunk to the sea floor. And it could remain a threat for years.
Much of the oil that has escaped from the site of the Deepwater Horizon is out of sight, underwater. George Maul is an oceanographer at the Florida Institute of Technology in Melbourne. He says if the slick spreads into areas just offshore, "upwellings," or rising water columns, could keep bringing blobs of oil onto Gulf beaches.
"Some of that material will get into the more shallow waters and then a storm comes through and kicks it up again, and also other events can cause it," says Maul. "Those upwellings will certainly be bringing materials closer to the coast and farther up into the water column, closer to the surface."
Maul notes an oil spill from a boat collision at the mouth of Tampa Bay in 1993 kept sending tar balls onto local beaches after big storms for four years.
He says oil that floats in the Gulf's mid-levels - or sinks to the bottom - can take a different path than what we see on the surface. And if the oil gets into the Loop Current, some of the deeper underwater flow can take it south, into the Carribean.
"As far as the currents are concerned, there are lots of questions we don't know yet," Maul says, "and there is plenty of evidence for currents going in opposite directions at the bottom, to what you see at the surface."
Maul says that could mean that tar balls that have fallen to the depths of the Gulf could show up in unexpected places, creating more uncertainties for any cleanup.
To hear the full interview with George Maul, click on the "Full Audio" icon below.
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