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Coastal Elevation Models

Coastal digital elevation models (DEMs) help researchers and decision makers understand and predict environmental changes that affect coastal regions. DEM data is used in a wide range of critical monitoring activities, including coastal process modeling (tsunami inundation, storm surge, sea-level rise, contaminant dispersal, etc.), ecosystem management, habitat research, coastal and marine spatial planning, hazard mitigation, and community preparedness.

Tsunami inundation grid, Monterey Bay, CA

Access Methods

Coastal DEM data can be accessed in a variety of formats and file structures using a variety of services.

Interactive Map

The Bathymetric Data Viewer is an interactive map application that provides access to a variety bathymetric data, including Coastal DEMs.

Bathymetric Data Viewer

Direct Access

Tiled Coastal DEMs

Search by map at NOAA's Digital Coast Data Access Viewer:

Continuously Updated Digital Elevation Model (CUDEM) - 1/9 Arc-Second Resolution Bathymetric-Topographic Tiles 

Continuously Updated Digital Elevation Model (CUDEM) - 1/3 Arc-Second Resolution 

Hawaii: Continuously Updated Digital Elevation Model (CUDEM) - 1/9 Arc-Second Resolution Bathymetric-Topographic Tiles

Hawaii: Continuously Updated Digital Elevation Model (CUDEM) - 1/3 Arc-Second Resolution Bathymetric-Topographic Tiles 


DEMs are referenced to a variety of horizontal and vertical datum with a spatial resolution range of 1/9 arc-second (~3 meters) to 3 arc-seconds (~90 meters).

Tiled vs Non-Tiled

NCEI has two types of Digital Elevation Model: Tiled make up a framework that seamlessly depicts merged bathymetry and topography along U.S. coasts. These models telescope from the deep ocean floor to the coastal zone in 3, 1, 1/3, and 1/9 arc-second cell sizes. The 1/9 arc-second DEMs integrate both bathymetric and topographic data at the coast, while the offshore DEMs map bathymetry only. DEMs are tiled to enable targeted, rapid updates as new data become available.

The benefits include maximizing the value of the NOAA funded source data, as well as interagency funded collections, by reducing the time it takes to incorporate into a gridded topobathy product (“Map Once, Use Many Times”) and by ensuring modeling efforts and other scientific applications use data that best reflect current morphology.

DEM Program Components Details

Tiled DEM Development

The development of high resolution, tiled DEMs in the coastal zone (1/9th and 1/3rd arc-second), extending from:

  • East & Gulf Coasts - inland to Sea, Land, Overland Surges from Hurricanes (SLOSH) Maximum over Maximum (MOM) surge extents and one ⅓ DEM tile offshore.
  • West Coast - inland to the tsunami inundation line as by state and one ⅓ DEM tile offshore.
  • Targeted updates to high-resolution tiles as new source data becomes available.
  • Prioritize NOAA funded data.

Establishing consistency between local/regional/global DEMs

  • Using higher resolution DEM data to update coarser resolution products at the regional/global scales. For example, the local 1/9th and 1/3rd DEM tiles are resampled and assimilated into existing, coarser coastal relief models (CRMs) and global models (e.g., ETOPO).


Data Sources

  • NOAA National Ocean Service
  • U.S. Geological Survey
  • U.S. Army Corps of Engineers
  • Federal Emergency Management Agency
  • Other government agencies, academic institutions, and private companies

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