This illustration shows the route traveled by oil leaving the subseafloor reservoir as it travels through the water column to the surface and ultimately sinks and falls out in a plume shape onto the seafloor where it remains in the sediment. (Illustration by Jack Cook, Woods Hole Oceanographic Institution)
Oil and methane bubble to the ocean's surface from natural seeps off Coal Oil Point, near Santa Barbara, California. (Photo courtesy of Dave Valentine, UCSB)
I investigate what happens to oil spilled into the ocean—with an eye toward finding better ways to “engineer” cleanups. But the brass ring has always hung out of my reach. When oil hits the water, chemical changes start occurring fast. It’s not like I can predict where or when an accidental spill is going to occur, so I usually can’t get to spills fast enough. I literally and figuratively miss the boat.
But I got a break in January 2005. I was aboard a 20-foot motorboat a mile offshore from the campus of the University of California at Santa Barbara (UCSB) with my colleague, Dave Valentine, a UCSB marine geochemist. The water was calm and flat—dampened by a widespread, iridescent film of oil on the surface. Big oil patties floated about. The air smelled like diesel fuel.
By any definition, it was a classic oil spill. But we were the only boat in the area—no Coast Guard, no oil booms, no throngs of cleanup crews in white Tyvak suits, no helicopters, no media, and no shipwreck.
Why? Because this oil spill was entirely natural. The oil had seeped from reservoirs below the seafloor, leaked through cracks in the crust about 150 feet (45 meters) under water. Lighter than seawater, the escaped oil floated to the ocean surface.
It was one of those days in your career that you never forget. Adrenaline raced through my body, and my brain was in overload, thinking about the research that could be done at this site. Nature was offering an ongoing experiment that was impossible (not to mention illegal) for me to perform. Off Santa Barbara, there’s an oil spill every day, allowing us to take a close look at a process that previously eluded our grasp.
I vividly remember standing on the boat and calling my lab manager, Bob Nelson, telling him to book a plane ticket and pack a long list of gear. We returned days later to start investigating the fate of oil in the coastal ocean, using this readily accessible natural laboratory.