Oil that naturally seeps from the seafloor to the surface of the ocean off the coast of Santa Barbara served as a laboratory of sorts as scientists worked to develop a new tools for use in a spill emergency.
The reliability of these seeps drew the Marine Oil Spill Thickness (MOST) project, a collaboration between NASA and the National Oceanic and Atmospheric Administration (NOAA).
The MOST team has worked to develop a way for NOAA – the lead federal agency for detecting and tracking coastal oil spills – to use remote-sensing data to determine not just the source of the oil but also thickest parts. This critical detail can help as they direct response and remediation activities.
“The idea here is that in two years or so when the MOST project is over, we’ll have a prototype system for detecting oil thickness that NOAA can use and distribute during oil spill response,” said Cathleen Jones, MOST co-investigator at NASA’s Jet Propulsion Laboratory. “With NASA partnering with NOAA, we can transfer this information to those who can use it practically.”
The team recently concluded a fall field campaign in Santa Barbara using the oil seeps as a natural laboratory.
“We’re using a radar instrument called UAVSAR to characterize the thickness of the oil within an oil slick,” Jones said.
“This thicker oil stays in the environment longer and damages marine life more than thin oil. And if you know where it is, you can direct responders to those problematic areas,” Jones added.
NASA’s UAVSAR, or Uninhabited Aerial Vehicle Synthetic Aperture Radar, attaches to the fuselage of an airplane that collects a roughly 12-mile-wide image of an area.
But SAR photos are unlike those acquired from other sensors.
Any smooth, oily areas appear darker than the surrounding clean water in the SAR imagery – the thicker the oil, the darker the area will appear.
To validate the airborne observations scientists go to the same area on a boat to measure the thickness of the oil by hand.
“We put the sampler, which is like a tube that’s open on both ends, in the water and let it sit there for a moment,” said Ben Holt, also a JPL co-investigator for MOST. “And then when you close off the tube, a small layer of oil and water is collected. After the oil layer settles, you can measure the oil layer thickness and compare that with the UAVSAR observations to see how closely they match up.”
They also can deploy a drone carrying an optical sensor, which is capable of observing the slick and measuring its thickness over a broader area.
Coincidentally, as the team prepped for this year’s fall campaign, authorities were responding to an oil spill near Huntington Beach, 130 miles south Santa Barbara.
Several members of the MOST team provided data on the spill, testing UAVSAR’s usefulness for a real emergency, not just a drill.
“It was really different from doing a practice run because people were overwhelmed running the response,” Jones said. “But when NOAA got the UAVSAR data, they used it to delineate oil, and then they released a Marine Pollution Surveillance Report based on it.
“It was the first time that had ever been done using data from an airborne instrument.”
The experience gained at the Huntington Beach incident didn’t cancel the planned Santa Barbara coast drill since the related measurements by boat could not be collected for comparison.
UAVSAR is a prototype for an upcoming satellite mission called NASA-ISRO Synthetic Aperture Radar, or NISAR, which is a partnership between NASA and the Indian Space Research Organisation (ISRO).
That mission is targeting launch from India in early 2023.
— Noozhawk North County editor Janene Scully can be reached at jscully@noozhawk.com. Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.