Mapping oil for the Deepwater Horizon oil spill disaster in the Gulf of Mexico

The explosion and eventual sinking of the Deepwater Horizon oil platform on April 20, 2010 off the southeast coast of Louisiana began one of the greatest man-made disasters in United States history. Shortly after the explosion, oil began leaking from the broken wellhead nearly one mile beneath the surface of the Gulf of Mexico. Approximately 40 hours into the spill, the first satellite derived oil spill analysis was issued by the National Oceanic and Atmospheric Administration (NOAA)/National Environmental Satellite, Data, and Information Service Satellite Analysis Branch (NESDIS/SAB). At the time, SAB was in the process of developing the capability to detect marine oil slicks in high resolution satellite imagery. The development of the Marine Pollution Surveillance Program began in December 2008 following a request for the need for analysis support for oil spills by NOAA's National Ocean Service (NOS). These analyses, known as Experimental Marine Pollution Surveillance Reports (EMPSR's) were initially intended for NOAA, the U.S. Coast Guard, Mineral Management Service (MMS), Department of Homeland Security, and other first responders of the oil spill in the Gulf of Mexico. Geographic Information System (GIS) shapefiles depicting the location of the spilled oil were also provided for use by those who were working to clean up and track the oil.

The Experimental Marine Pollution Program of NESDIS/SAB consists of manual detection and mapping of oil slicks through the use of available moderate to high resolution visible imagery such as MODIS (NASA) and MERIS (ESA), and more primarily using space-based Synthetic Aperture Radar (SAR) imagery, which during this disaster included RADARSAT (Canadian), Cosmo SkyMed (Italian), Envisat (ESA), Advanced Land Observation Satellite (Japanese), and TerraSAR-X (German). SAR imagery has proven to be a useful tool in capturing oil slicks because it depicts the wave-suppression that oil causes on the sea surface, provides wide spatial coverage, and works day or night. As the disaster continued through the summer, it became apparent that very high resolution visible imagery, such as ASTER (NASA/JPL) and SPOT (French) imagery would be more important given the smaller size of the oil slicks and their closer proximity to the shorelines of the Gulf states.

In addition to the EMPSR's issued for each satellite image that was analyzed for the oil spill, NOAA's NESDIS/SAB also created a Daily Composite product, starting on May 17th, for each day that suitable satellite coverage was available. This product gave an overall view of all of the surface oil present in the waters off the Gulf coast on any one specific day. Over the entire length of the oil spill in the Gulf of Mexico, over 300 EMPSR's were issued along with more than 75 Daily Composite products, which greatly assisted the many organizations and first responders working to locate and clean up areas contaminated by the oil from the Deepwater Horizon.