Data Collection

Applying the criteria in Article 76 of the Law of the Sea Convention requires data on the morphology of the seafloor and, in some areas, the thickness of the underlying sediment. For this reason, the ECS Project has conducted field programs necessary to collect bathymetric and seismic data.  Data collected as part of the U.S. ECS Project are made available to the public and can be downloaded from NOAA’s National Centers for Environmental Information.

Bathymetric Data

Bathymetric data are collected using state-of-the-art multibeam echosounders that provide a three-dimensional map of the surface of the seafloor. These data are important for applying the criteria in Article 76, including identifying the foot of the slope and 2,500 meter isobaths (i.e., depth contours).

Since 2003, NOAA has mapped more than 3 million square kilometers of the ocean floor in support of the U.S. ECS Project, an area 5 times the size of Texas. Bathymetric data have been collected using state-of-the-art multibeam echosounders on 37 separate cruises from 14 ships in 10 regions totaling nearly 2.5 years of sea time. This is the largest offshore mapping effort ever conducted by the United States. Bathymetric data collection is coordinated by NOAA and undertaken by the Center for Coastal and Ocean Mapping/NOAA Joint Hydrographic Center, a cooperative partnership between NOAA and the University of New Hampshire.

Seismic Data

Seismic data is required in some regions; it provides information on the depth, thickness, geometry, and other characteristics of the sediments beneath the seafloor.  The ECS Project requires seismic data to derive the thickness of the sediment for those regions where the sediment thickness formula in Article 76 applies.

Seismic data collection for the ECS Project is coordinated through the U.S. Geological Survey (USGS).  Seismic data has been collected in the Arctic, Atlantic, Bering Sea, and Gulf of Alaska (Table 2).  USGS made significant efforts to minimize the impact of seismic data collection on living resources through careful planning, obtaining the applicable authorizations, and following mitigation strategies.

Seismic data collection in the Arctic Ocean was undertaken cooperatively with Canada.  The U.S. Coast Guard Cutter (USCGC) Healy collected multibeam bathymetric data and created a straight and open path through the ice for the Canadian Coast Guard ship Louis S. Saint Laurent, which followed collecting seismic reflection and refraction data with sensors towed behind the stern of the ship.

For more information on data collection, please visit other U.S. ECS Task Force Websites

NOAA National Centers for Environmental Information  

U.S. Geological Survey ECS Website  

Center for Coastal and Ocean Mapping/NOAA Joint Hydrographic Center  

NOAA Ocean Exploration Program