An oil slick from naturally occurring oil seeps off the coast of Santa Barbara, California. The NASA-NOAA Marine Oil Spill Thickness (MOST) project is using the area to test the ability of a radar instrument called UAVSAR to detect the thickness of oil in oil slicks – important information for first responders to oil spills. Having concluded their second field campaign in Santa Barbara at the end of October, 2021, the MOST team is working 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 where oil is, but where the thickest parts of it are. NASA's UAVSAR, or Uninhabited Aerial Vehicle Synthetic Aperture Radar, attaches to the fuselage of an airplane that collects a roughly 12-mile-wide (19-kilometer-wide) image of the area. The instrument sends radar pulses down to the surface of the ocean, and the signals that bounce back are used to detect roughness, caused by waves, at the ocean's surface. Oil dampens the waves, creating areas of smoother water that appear darker than the surrounding clean water in the SAR imagery – the thicker the oil, the darker the area appears. When the project concludes, likely in 2023, scientists hope to have a prototype system for detecting oil spill thickness that can be deployed in emergencies. https://photojournal.jpl.nasa.gov/catalog/PIA23699

A C-20 based at NASA’s Armstrong Flight Research Center in Edwards, California, departs to use its Uninhabited Aerial Vehicle Synthetic Aperture Radar to support the Marine Oil Spill Thickness mission. Thousands of gallons of oil seep through cracks in the ocean floor and rise to the surface just off the coast of Santa Barbara. It’s one of the largest naturally occurring oil seeps and serves as a laboratory for NASA and the National Oceanic and Atmospheric Administration to test automated oil spill detection, oil extent mapping, and oil thickness characterization.