But the differences between the two events are significant, cautions Michelle Wood, a marine biologist who recently became head of the ocean chemistry division of the National Oceanic and Atmospheric Administration's Atlantic and Oceanographic and Meteorological Laboratory in Miami. Not the least of those differences is the seascape into which the oil is flowing.
The Exxon Valdez spill involved a large, single, intense pulse of oil into Prince William Sound – "a shallow, near-shore environment with a rocky coast," she explains. The heavy crude had lots to cling to as it came ashore. In the Gulf, "spill" is a so-far continuous infusion of a lighter grade oil, which at least initially forms a foamy mousse rather than tarry blobs. And so far, the oil has remained far at sea.
The apparent gap between preparations for the oil's arrival along the Gulf Coast and its behavior so far testify to the complex marine environment the oil enters as it spews from the broken well head, researchers say.
The system is chaotic enough that given enough time, say 90 days, oil in some form could wind up anywhere from the Mexican Coast to Palm Beach, research suggests.
"We call it a mini ocean," says Steven DiMarco, an oceanographer at Texas A&M University in College Station, Texas. "Many of the processes that occur in the Gulf of Mexico occur in the much larger basins like the Atlantic and the Pacific."