Observatory Books’s Stock Inventoried

If you were wondering what happened to Observatory Books’s inventory after it closed its doors last November, the Juneau Empire has the story: it took more than three months for historian Patti David to sift through “every map cabinet and stack of paper in every corner of the bookstore”; the store’s collection of Alaskana will be shipped to Seattle to make it easier for collectors to purchase. [WMS]

High-Resolution Elevation Data Released for Alaska

The White House
The White House

A new digital elevation model of Alaska was released earlier this monthThe result of a presidential directive to improve elevation maps of Alaska as a tool “to help to help communities understand and manage” the risks of climate change, the ArcticDEM project is a collaboration between the National Geospatial-Intelligence Agency (NGA), the National Science Foundation (NSF) and the University of Minnesota, among others. The unclassified data gives two-metre (or better) resolution across the state. Lower-resolution DEMs for the entire Arctic will follow next year.

Digital elevation data for Alaska had previously been poor; the National Geographic article leads with the point that Mars has better topographic maps than Alaska does. Most digital elevation data is collected by airplane—an impractical method in the far north; the ArcticDEM is based on stereo imagery from DigitalGlobe satellites. (As a comparison, the Shuttle Radar Topography Mission’s DEM resolution is 30 metres for the U.S., 90 metres elsewhere.)

ArcticDEM data is available on the ArcticDEM Explorer page and on the NGA’s Arctic Support 2016 page.

After the cut, a comparison of digital elevation models pre- and post-ArcticDEM, using Anchorage, Alaska.

Continue reading “High-Resolution Elevation Data Released for Alaska”

Digital Geologic Map of Alaska

A new geologic map of Alaska has been published by the U.S. Geological Survey. From the USGS release: “This map is a completely new compilation, carrying the distinction of being the first 100 percent digital statewide geologic map of Alaska. It reflects the changes in our modern understanding of geology as it builds on the past. More than 750 references were used in creating the map, some as old as 1908 and others as new as 2015. As a digital map, it has multiple associated databases that allow creation of a variety of derivative maps and other products.” The map is available traditionally in two PDF sheets, as well as in geodatabase, Shapefile and other database formats.