Extending to the outer limits of the exclusive economic zone and covering approximately 3.6 million square nautical miles, U.S. oceans, coasts, and Great Lakes waters comprise the largest area of national seafloor mapping responsibility in the world.
As of January 2020, only 46% of U.S. waters have been mapped at 100 meter resolution. The remaining 54% is considered unmapped, which means that either no direct measurements of the seafloor have been acquired over these areas or data has been collected and not made publicly available. The image below shows the extent of the unmapped areas within U.S. waters.
The table below shows how far we have progressed between October 2017 and January 2020 and how much we need to progress to reach the Seabed 2030 goal within U.S. waters. Between October 2017 and October 2018, the unmapped portion of U.S. waters went from 59% to 57%. In January 2020, the unmapped portion went down from 57% to 54%. Assuming that we fill bathymetry data gaps for 3% of all U.S. waters each year, we are projected to have about 200,000 square nautical miles of seafloor left to map by 2036. This remaining area is approximately equal to the nearshore areas that are the most difficult and time-consuming to map. To account for this challenge, we assume our rate of progress will reduce to 1% per year. This projection shows that we will complete this baseline mapping in/around 2041. It is noteworthy that this forecast is optimistic and does not take into account the numerous logistical challenges with offshore and coastal mapping.
Based on the January 2017 analysis, we need to acquire annually bathymetry for 161,685 square nautical miles (554,564 square kilometers) of coastal, ocean, and Great Lakes seafloor in order to reach Seabed 2030 goals. This annual mapping goal is approximately equal to the total land area of the states of Montana and North Dakota combined (555,673 square kilometers). Because we are already behind, we also need to acquire an additional 340,100 square nautical miles of bathymetry in 2020 to track with the Seabed 2030 timeline and goal.
It should be clear from these projections that we need to radically change the way we do business in order to fill the mapping gaps within U.S. waters by 2030 or 2041. This effort requires a multifaceted solution, including the acquisition of new data, making previously collected bathymetric data publicly accessible, and improvements in technology to make mapping more efficient.
For a one page Progress Report of Unmapped U.S. Waters as of January 2020, please click on the link below: https://iocm.noaa.gov/seabed-2030/mapping-progress-report2020.pdf