As tempests go, tropical storm Bonnie would barely be strong enough to cause a Louisianan to look up from his gumbo. As of Friday evening, the National Hurricane Center actually downgraded Bonnie to a tropical depression, with winds only around 35 mph—below the 39 mph minimum needed for to be an official tropical storm. If this were any other year, Bonnie would be a footnote in what’s expected to be a rough hurricane season.
But 2010 is the summer of the spill, and while Bonnie may not be strong, it’s right on track to hit the site of the Deepwater Horizon spill, as this map from Accuweather shows:
Accuweather predicts the storm to reach the spill site Saturday morning, making landfall on the Gulf coast late Saturday night. The storm was strong enough to force BP to halt its relief well operations, with the drilling rigs pulling out late Thursday night. At a briefing on Friday morning, retired Coast Guard Admiral Thad W. Allen that the drilling rigs as well as the Q4000 platform will be moved away from the spill site, out of reach of the storm—and that other ships would follow soon, barring a last-minute swerve from Bonnie. Other ships—the seismic survey vessels, the acoustic survey vessels and the ships that control the remote operated vehicles (ROVs)—would stay longer, in part because they can move faster than the drilling rigs. But because Bonnie relatively weak, Allen expects the work stoppage to be brief—though it will take longer to get the relief well drilling rigs back and ready to work. “If we have to evacuate the scene we’re probably looking at a very limited window, something around 48 hours,” said Allen. “In the meantime our priorities are safety of personnel that dictate the movement of the vessels, and then preservation of the equipment and their ability to come back in and complete their operations as well.”
While the well will remain capped during the storm, if all the vessels have to leave, there will be no real-time monitoring of the well for the first time since the spill began more than three months ago. (The spillcam will go dark!) That’s a little worrying—though the well has remained cap for a week without any serious problems, this is all uncharted territory. Allen said that BP will leave behind hydrophones near the well that will offer some acoustic monitoring of the site—though they’ll only be able to access the recordings once the vessels are back on scene. “Our only real-time feedback will be aerial surveillance and satellite imagery,” Allen said.
The bigger concerns have to do with what the storm might do to the oil spill itself, near the Gulf shores. It could be a positive, as the strong waves created by the storm could naturally break up oil slicks, speeding the natural process of biodegradation and dispersal—like chemical dispersants without the unfortunate toxic side effects. On the other hand, the storm will surely disrupt cleanup efforts along the shore, just as Hurricane Alex did. It will be too rough for skimmers and other boats to operate, and the waves will almost certainly displace the thousands of miles of shore boom that have been laid so far—putting those coastal defense back together will be a headache.
Worse, the storm could drive oil in the water up onto the beaches and further into sensitive marshes along the Gulf coast. So far the damage has been limited to the coastline—in the marshes of southeastern Louisiana, you can see the oil has usually soaked in a few ft. from the water’s edge, but no deeper. A serious storm surge could bring toxic oil and dispersants inland, where it will be far more difficult to clean up. “Sometimes the increased action on the surface can actually help with emulsification of the oil and the distribution and biodegredation,” Allen said. “On the other hand you have the chance that a storm surge can drive that up into the beach and the marshes, where it would not have been driven otherwise.”
So good news/bad news—as it’s usually been with this spill, which is still far from over.