http://www.livescience.com/43729-exxon-valdez-oil-persists.html
[Multiple images and links in on-line article.]
Small pockets of oil from the 1989 Exxon Valdez oil spill still persist
in pockets along Alaska's coasts, hidden by rocks that have kept the
elements from breaking down the crude oil, scientists reported yesterday
(Feb. 27).
The Exxon Valdez spill was the largest oil spill in U.S. history until
2010's Deepwater Horizon disaster, with nearly 11 million gallons (40
million liters) of oil pouring into Prince William Sound. (For
comparison, the Deepwater Horizon spill spewed more than 200 million
gallons, or 750 million liters, of oil into the Gulf of Mexico.)
During a study aimed at finding out how long oil persists after a spill,
a group of scientists examined the Shelikof Strait coastline southwest
of the spill site. They found pockets of oil hidden behind stable
boulders that seem to protect the oil from the actions of waves and
other forces that break the oil down over time, keeping it in a state
similar to when it was first spilled.
"To have oil there after 23 years is remarkable," Gail Irvine of the
U.S. Geological Survey's Alaska Science Center said in a statement. "We
have these marked boulders whose movement we've been studying for more
than 18 years. The oil itself has hardly weathered and is similar to
11-day-old oil."
Oil drilled from different locations has different chemical
fingerprints, and chemists were able to test the unweathered oil and
confirm that it came from the Exxon Valdez, which was carrying oil from
Alaska's Prudhoe Bay. [SOS! Major Oil Disasters at Sea]
Christopher Reddy, whose lab at the Woods Hole Oceanographic Institution
in Massachusetts did the "fingerprinting" of the oil, said that the
study showed something of a silver lining in the Exxon Valdez spill, in
that scientists are learning which compounds in oil are more or less
susceptible to weathering and where oil tends to persist after a spill.
"One lesson is that if you are responsible for cleaning up a spill, you
want to be proactive about cleanup behind the boulders," Reddy said in
the statement.
The researchers, who presented their work yesterday at the American
Geophysical Union's annual Ocean Sciences Meeting in Honolulu, did note
that the amount of oil they found is a small fraction of the total oil
spilled and that the findings can't necessarily be extended to the whole
of the spill area.
--
Darryl McMahon
It's your planet. If you won't look after it, who will?
_______________________________________________
Sustainablelorgbiofuel mailing list
Sustainablelorgbiofuel@lists.sustainablelists.org
http://lists.eruditium.org/cgi-bin/mailman/listinfo/sustainablelorgbiofuel