How much of Alaska's seafloor has actually been mapped?
Alaska has more coastline than all other US states combined - and most of its ocean floor is a mystery.
The answer
As of 2025, only 38% of Alaska's seafloor has been mapped, despite the state having more coastline than all other US states combined - approximately 10,690 km of general coastline and over 54,000 km of tidal coastline. NOAA and partner organizations are actively working to explore priority regions including the Aleutian Islands, the Bering Sea, and Arctic waters. The unmapped areas potentially harbor undiscovered submarine volcanoes, hydrothermal vents, seamounts, and unique deep-sea ecosystems. Mapping the seafloor is critical for navigation safety, fisheries management, tsunami preparedness, and understanding the impacts of rapidly warming Arctic waters on marine ecosystems. The effort is part of the broader global Seabed 2030 initiative to map the entire ocean floor by 2030.
Source: NOAA Ocean Exploration
- alaska
- seafloor-mapping
- noaa
- arctic
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