Exploring Arctic Elevation
An innovative partnership has produced dramatically-improved elevation data for Arctic regions.
A collaborative Arctic mapping effort has made Arctic elevation data available in unprecedented detail. Today the Arctic DEM project is releasing detailed elevation data for Alaska and will complete similar elevation data for the entire Arctic by 2017.
The project is a collaboration among
• The National Geospatial-Intelligence Agency (NGA)
• The National Science Foundation (NSF) and
• The University of Minnesota’s Polar Geospatial Center (PGC)
To broaden access and enhance usability Esri joined the partnership to make the elevation data more actionable by providing Web services and apps that allow users to display and analyze this elevation data in a variety of ways.
Scroll down to explore a sampling of visualizations of the Arctic elevation data.
Satellite image
This is a Landsat image of an area near southern Alaska's Tazlina Glacier.
Conventional shaded relief
This rendering of the same area, based on the new elevation data, represents relief with shades of gray with illumination from the northwest.
Multi-directional hill-shade
In this version the same terrain is illuminated from six different directions. This offers a higher degree of detail than traditional shaded relief, which uses only one illumination source.
Tinted hill-shade
Here, color has been added to the shaded relief.
Slope
In this visualization, colors denote steepness of slopes. Steeper slopes are shown in darker colors (orange and brown); more gentle slopes are represented in yellow and white.
Aspect
This version shows the orientation of sloping terrain as different colors. Green areas face north, blue east, magenta south, and orange west.
Contour lines
The elevation data can be used to render contours. In this case, contour lines are at 25-meter intervals, and are shown atop shaded relief.
A web application developed by Esri enables users to select an area and calculate elevation change over time.
Above: an elevation rendering of Wolverine Glacier from July 7, 2009.
Using the app's timeline function reveals a scene from August 30, 2015. If you compare this with the image above, you’ll notice that the glacier has receded.
While the timeline tool is open, you can click a point on the map to generate an elevation timeline. Notice the downward trend here, indicating a decrease in elevation.
This tool works in conjunction with a "delta," or change tool. If you click a point on the graph, then click the Save button in the top right; click another point on the graph, then click the delta button, you get the results below:
The Measure Change tool subtracts one scene from another. We chose to subtract the August 2015 scene from the July 2009 scene. We see a lot of red here, indicating a decrease in elevation.
We can then sketch an area on the map calculate the total volume lost in the drawn area between the two scenes.
The image above shows the elevation profile tool. It also allows you to measure distance and area.
The Identify tool reveals the source information for the scene at a point you select on the map and gives you height measurements.
Elevation data (gray areas on map) is now available for most of the Arctic region.
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The images above represent a small sampling of what can be done with the Arctic elevation data. For more information, applications, and tools, see the links below.
To explore this data in a custom web application, the Arctic DEM Explorer from Esri enables users to explore an interactive map of the arctic region and toggle among data visualizations.
Esri’s polar elevation services now also include full coverage of Antarctica. Begin exploring Antarctica via the Antarctic REMA Explorer.
Additional Arctic and Antarctic DEM maps and layers can be found in the ArcGIS Living Atlas of the World.
Former President Barack Obama's White House Blog provides additional information about the origin of the Arctic and Antarctic elevation projects.
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