Integrated Ocean and Coastal Mapping

Map Once, Use Many Times

Status of Seafloor Mapping Within U.S. Waters

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 2021, only 47% of U.S. waters have been mapped at 100 meter resolution. The remaining 53% 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 shared for broader use. The image below shows the extent of the unmapped areas within U.S. waters.

Map showing the geographic distribution and extent of the unmapped areas within U.S. waters. Analysis conducted in 
						  January 2021.

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. 

 In January 2021, we acquired 36,100 square nautical miles of new bathymetric data coverage-- far short of our goals.

Table showing the actual unmapped areas remaining between 2017 and January 2020 with projections for how much unmapped areas 
					  remain if we fill bathymetry data gaps for 3% of all U.S. waters each year until there are 200,000 square nautical miles remaining. 
					  For the remaining unmapped area, the rate of progress was dropped to 1% in anticipation of further challenges in mapping nearshore 
					  areas.  Following this trend (shown in red), we may reach the Seabed 2030 goal in 2041.  Alternatively, we show how much we need to 
					  acquire annually starting in 2017 to reach the Seabed 2030 goal and timeline (shown in grey with black bars).

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. 

Progress Reports of Unmapped U.S. Waters: - January 2021 - March, 2020