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Alaska Bathymetry, Sediments, and Smooth Sheets

Archived page of bathymetry data.

NOAA is mandated to identify Essential Fish Habitat by provisions of the Magnuson-Stevens Act, but the necessary data sets are not always available. In the marine environment, depth and sediment type are often the most important determinants of Essential Fish Habitat for fish that live on the bottom. Bathymetry data can be further analyzed into important habitat descriptors such as slope and roughness. Marine researchers are familiar with National Ocean Service nautical charts, which are often considered the most useful source of Essential Fish Habitat information in Alaskan waters. The small scale (often 1:100,000 or smaller) means that the nautical charts lack significant fish habitat details. However, what most marine researchers do not know is that these National Ocean Service nautical charts are derived from more detailed, larger-scale (often 1:20,000) charts called "'smooth sheets," which are the final published product from the original charting surveys.

Map showing features of the sea floor near Kodiak Island in Alaska
Physically, a paper smooth sheet with muslin backing was the final product of a hydrographic survey. The soundings were drawn on a smooth sheet, along with the shoreline, geographic features (e.g., kelp beds, rocky reefs, islets, rocks), seafloor substrates (e.g., gravel, sand, mud), and the navigational signals to provide a visual record of the hydrographic survey, which could be annotated as new information became available.

What are Smooth Sheets?

Details of how to work with smooth sheets are available in How to work with Smooth sheets

Bathymetry of Aleutian Islands: 2013

Map showing features of the sea floor near the Aleutian Islands
Bathymetric surface of Aleutian Islands compiled from National Ocean Service hydrographic surveys and supplemented with some non-hydrographic surveys.

Details of our processing methods can be found in Smooth Sheet Bathymetry of the Aleutian Islands, NOAA Tech Memo NMFS-AFSC-250.

Data Available for Download

DATA NOT TO BE USED FOR NAVIGATION

Bathymetry of Cook Inlet

Map of Cook Inlet in Alaska

Scientists with the Alaska Fisheries Science Center’s Groundfish Assessment Program expanded their mapping study of the Aleutian Islands to include Cook Inlet, Alaska. 

Details of our processing methods can be found in Smooth sheet Bathymetry of Cook Inlet, Alaska. NOAA Tech. Memo. NMFS-AFSC-275.

Bathymetry of Central Gulf of Alaska

Map showing underwater features of the Gulf of Alaska
Bathymetry data for the Gulf of Alaska.

Alaska Fisheries Science Center scientists in the RACE Groundfish Assessment Program proofed, corrected, and digitized 1.75 million lead-line and single-beam echosounder soundings collected in the central Gulf of Alaska and represented in 225 National Ocean Service hydrographic survey smooth sheets. This bathymetry compilation extended over an approximately 1,400 km arc of continental shelf from the Trinity Islands in the west to Cape Ommaney in the east.

Details of our processing methods can be found in Smooth Sheet Bathymetry of the central Gulf of Alaska, NOAA Tech Memo NMFS-AFSC-287.

Bathymetry of Norton Sound

Bathymetry for Norton Sound.
Bathymetry for Norton Sound.

As a continuation of work in Alaskan waters, scientists with the Alaska Fisheries Science Center’s Groundfish Assessment Program have published smooth sheet bathymetry for Norton Sound, Alaska. This work is part of a project using smooth sheets to provide better seafloor information for fisheries research.

Details of our processing methods can be found in Smooth Sheet Bathymetry of Norton Sound, NOAA Tech Memo NMFS-AFSC-298.

 

Additional Resources

Last updated by Alaska Fisheries Science Center on January 14, 2026