Matt Nolan and his family have created a topographic map of Denali, the highest peak in North America, using a form of stereo photogrammetry Nolan calls fodar: they repeatedly overflew the peak in a small airplane and took photos of the terrain below with a digital SLR. The end result is a 20-cm terrain model they’re touting as the best ever of the mountain, far more detailed than previous maps. Nolan outlines their endeavour in two blog posts: one focusing on the personal, the other on the technical; the latter also has lots of terrain models and comparisons with USGS data.
If Shetland gets relegated to inset maps all the time, that goes double for Alaska, which on maps of the United States gets reduced in scale too. In response, this map turns the tables by relegating the lower 48 (as well as Hawaii) to a tiny and crude inset map. The 17×25-inch paper map costs $15. [Maps on the Web]
A lecture by independent historian John Cloud about indigenous contributions to early American mapmaking and surveys of the newly acquired territory of Alaska is now online. The lecture, titled “The Treaty of Cession, as Seen through the Lenses of Art, Cartography, and Photography,” is 80 minutes long and full of interesting stuff about the early history of Alaska. Cloud gave the talk on 15 November at the Sealaska Heritage Institute in Juneau, as part of the institute’s Native American Heritage Month. Local public radio station KTOO had a short article on the talk last month. [Tony Campbell]
A new digital elevation model of Alaska was released earlier this month. The 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.)
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.