A new report from the U.S. federal Interagency Working Group on Ocean Coastal Mapping has determined that 53% of the country’s ocean, coastal, and Great Lakes water remain unmapped. As with the rest of the global ocean, much of the ocean floor in the U.S. Exclusive Economic Zone (EEZ) is still unknown.
What is the exclusive economic zone?
An exclusive economic zone (EEZ) is the area that extends out from a country’s coastline that gives that country special rights over natural resources. According to NOAA, the United States has the largest EEZ in the world, with 13,000 miles of coastline and 3.4 million square nautical miles of ocean. (Other sources cite France as having the largest EEZ in the world)
Mapping the U.S. Seafloor
An annual report from NOAA is tracking how much of the U.S. seafloor has been mapping. In January 2021, unmapped areas represent 53% of total ocean, coastal, and Great Lake areas still need to be mapped.
A January 2020 analysis found that 54% of U.S. coastal, ocean, and Great Lakes seafloor remains unmapped. This is up from 57% in 2019 and 58% in 2018.
Of these areas, the Great Lakes has the most incomplete mapping with 95% of the freshwater areas unmapped. The Pacific Ocean areas of California, Oregon, and Washington have the lowest proportion that remains unmapped with only 22% of the area that still needs to be mapped.
This map of the U.S. EEZ shows the areas in red that remain unmapped as of January 2021.
Multibeam and LIDAR surveys are the primary technologies being used to map bathymetry, the measurement of depth of water in oceans and other bodies of water. This data comes from government, academia, and private sector efforts. Other strategies include the use of unmanned aerial vehicles, satellites, sonar, and crowdsourced bathymetry (collecting of depth readings from vessels using ordinary navigation instruments during routine maritime operations is known as crowdsourced bathymetry).
Mapping America’s waters. (2021, September 3). National Centers for Environmental Information (NCEI). https://www.ncei.noaa.gov/news/mapping-americas-waters
PROGRESS REPORT: Unmapped U.S. Waters. (2021, March). IOCM – NOAA. https://iocm.noaa.gov/seabed-2030/mapping-progress-report2021.pdf