According to a recent survey Denali (aka Mt.McKinley) is lower than previously thought. North America's highest mountain has lost about 25m; but of course that doesn't make it any easier.
The Alaskan giant was long believed to be 20,320ft/6193m, a figure obtained in a 1952 survey and quoted on maps ever since. Its revised height is 20,237ft/6168m, a reduction of 83ft or 25.29m - not much relative to the mountain's vast scale perhaps, but a surprise given the number of climbers equipped with GPS and altimeters who must have stood on the summit.
The new measurement using something called Interferometric Synthetic Aperture Radar was taken by the US Geological Survey in 2012, and the data has now been released as part of the agency's drive to update all of Alaska's topographic maps, the Alaska Mapping Initiative (AMI).
For the last half century mapping in Alaska has not kept pace with records for the rest of the US, the agency say, as a result of difficult terrain, remote locations, and vast distances. Modern mapping information does not exist over the majority of land in the state. Prior to this effort, topographical maps for much of Alaska were about 50 years out of date and not produced to current standards, which rely largely on high resolution digital imagery and elevation data.
Climbers and hikers visiting Alaska might like to know that the first 400-plus new maps for the state are now accessible. This is just the start of a multi-year project to produce more than 11,000 new maps for the entire state at a useful scale of 1:25,000 to replace the 1:63,360-scale maps produced about 50 years ago. The maps will be published in digital PDF format (GeoPDF©) and are available for free download.
There is more to the story than the shrinking of one famous mountain. According to Reuters, Alaska Lieutenant Governor Mead Treadwell said in a statement on Wednesday that the mapping initiative has also found an entirely new ridge on a nearby mountain, Mount Dickey - a major feature that had been omitted from previous documents.