New Map Data Finds Denali is Shorter
September 11, 2013, Anchorage, AK – Lt. Governor Mead Treadwell told a group of map collectors gathered in Fairbanks this week that Mt. McKinley may again be shorter than cartographers thought, according to new digital elevation map data collected by the State of Alaska and multiple federal agencies working in collaboration.
During a symposium of the International Map Collectors’ Society, Treadwell referenced orthometric survey data that recorded Mt. McKinley to stand 6,168 meters, as opposed to 6,194 – or 20,237 feet rather than 20,320.
“That’s 83 feet shorter than we thought,” Treadwell said. “The good news is: Denali is still the tallest peak in North America.”
Denali’s elevation was originally measured to stand 20,320 feet in 1952, based on photogrammetry. A 1989 field survey recorded an elevation of 20,306 feet – 14 feet shorter than the 1952 recording.
The 2012 revision of 20,327 feet was recorded with radar technology deployed as a result of Alaska’s Statewide Digital Mapping Initiative (SDMI), which also revealed that an entire ridgeline of Mt. Dickey in Denali National Park was missing from previous maps – one of many discrepancies corrected by recent map updates.
The State of Alaska invested $9.59 million in SDMI since 2010, and the federal government has invested $14 million toward the overall cost of creating a digital elevation model for Alaska. The initiative, nearly 50% complete, is on schedule for statewide completion by 2016.
U.S. Secretary of Interior Sally Jewell announced last week that the USGS has produced 400 new Alaska topographical maps, which are now available for public download. Altogether, the USGS project will produce more than 11,000 new maps covering the entire state.
“Alaska’s maps are nearly 50 years old and have never met National Map Accuracy Standards,” Treadwell told the audience. “The combined effort of multiple federal partners and the State of Alaska to get Alaska mapped is making great progress.”
Treadwell, along with Anne Castle, Assistant Secretary for Water and Science at the U.S. Department of Interior, has helped convene the Alaska Mapping Executive Committee to bring federal and state mapping efforts together. He says one goal of new maps is safer aviation in Alaska.
Links to survey reports follow:
Fugro EarthData Inc. report, June 2012 https://3f.ltgov.alaska.gov/treadwell_media/pdf/An%20Investigation%20of%20GeoSARs%20Orthometric%20Height%20for%20Mount%20McKinley.pdf
Dewberry report, July 2012