Luettich's simulations contradict mathematical modeling by NOAA of the likely movements of the ongoing oil spill, which shows a low probability of Texas being impacted and a general movement of the oil toward the east—in the absence of a hurricane.
Of course, a storm doesn't even have to come close to the slick to cause havoc, as Alex proved. "The main thing [hurricanes] do is generate waves, and those waves travel long distances," Luettich says. "They can have an impact on skimming and other efforts to stop the oil."
Alex's top winds of 160 kilometers per hour and the storm's path hundreds of kilometers south of the slick were enough to push tar balls to Galveston, Texas, and even into Lake Pontchartrain in Louisiana. "There is a good chance that the large circulation of Hurricane Alex contributed to westward advection of some of the tar balls related to the oil spill toward Louisiana and Texas," Marks says. But "it would be very hard to attribute the tar balls arriving only to the presence of Alex."
And if oil continues to need to be pumped from the ocean floor, operations will have to be shut down some 120 hours before a storm, according to Coast Guard Rear Admiral Thad Allen, who is directing the government's efforts to contain and clean up the oil spills. A new capped blowout preventer that BP has installed may avert that in future.
Oil, paradoxically, also has the effect of calming rough seas—as has been reported or demonstrated by scientists from Aristotle to Benjamin Franklin. A small amount of oil can dampen a large amount of waves, due to the differing surface tensions of the two fluids.
In fact, a German experiment reported May 15, 1989, in the Journal of Geophysical Research (pdf) found that oil does indeed depress waves, primarily by dampening short waves that then cannot transfer their energy to longer waves. "If you put oil on the surface, oil damps out small waves very effectively," Zappa says. But "they found this at regular winds, 20 knots at maximum, not a hurricane."
Oil also dampens evaporation. But given that the oil slick, despite covering 6,500 square kilometers, is still three to four times smaller than a hurricane, it is not expected to dampen the power of an onrushing storm. "The hurricane is going to be so strong that it would break up any slicks and cause them to be patchy. It's not going to have too much of an impact on evaporation," Zappa says. "That's the idea, but we don't know for sure."