An upcoming report intends to warn the Gulf Coast of a looming disaster that may dwarf the current BP gusher. 31,000 miles of under sea pipes move over a billion dollars of oil a day around the Gulf of Mexico, and much of it is crumbling apart. This new study suggests under water currents from a hurricane could be enough force to wreak havoc on an aging infrastructure that is being dug out of the ocean floor by the passage of time.
Based on unique measurements taken directly under a powerful hurricane, the new study’s calculations are the first to show that hurricanes propel underwater currents with enough oomph to dig up the seabed, potentially creating underwater mudslides and damaging pipes or other equipment resting on the bottom.
At least 50,000 kilometers (31,000 miles) of pipelines reportedly snake across the seafloor of the Gulf of Mexico. Damage to these pipelines can be difficult to detect if it causes only smaller leaks, rather than a catastrophic break, the researchers say. Repairing underwater pipes can cost more than fixing the offshore oil drilling platforms themselves, making it all the more important to prevent damage to pipelines in the first place.
The researchers, at the U.S. Naval Research Laboratory at Stennis Space Center, Mississippi, got an unprecedented view of a hurricane when Hurricane Ivan, a category-4 storm, crossed the Gulf of Mexico in 2004. The eye of the storm passed over a network of sensors on the ocean floor, put in place to monitor currents along the continental shelf in the Gulf.
The research team found that strong currents along the sea floor pushed and pulled on the seabed, scouring its surface. “Usually you only see this in very shallow water, where waves break on the beach, stirring up sand,” says David Wang, co-author of the study. “In hurricanes, the much bigger waves can stir up the seafloor all the way down to 90 meters [300 feet].”
Ivan’s waves on the surface created powerful currents that dug up the seafloor. Acoustic measurements using sound waves showed that these currents lofted a lot of sediments, which clouded the water up to 25 meters (82 feet) above the seafloor. The team’s seafloor sensors tracking the pressure underwater experienced a big increase, as well. This showed that the ground was washed away beneath the sensors, causing them to sink into a lower, higher-pressure zone.