There’s no question that at 20,310 feet, Denali is the highest peak in North America. The identity of the highest mountain beyond the Arctic Circle, however, was disputed for almost 60 years, Ria Misra at Gizmodo reports. Now, the matter has finally been resolved thanks to technology created by Matt Nolan, a glaciologist from the University of Alaska, Fairbanks.
While researchers had a pretty good grasp on the heights of mountains in the Wrangell, St. Elias and Alaska ranges in southern and central parts of Alaska, when it came to the Land of the Midnight Sun's Brooks Range, stretching 700 miles between the Arctic National Wildlife Refuge in Alaska and the Yukon above the Arctic circle, things were a little less certain.
The conflict dated back to 1956, when a USGS survey tried to map the Brooks Range, Misra reports. One set of data indicated Mt. Chamberlin was the highest, while another map with a different scale said Mt. Isto was the highest.
Historically, measuring a mountain has been pretty difficult—in the past, trigonometric methods were used, but they are often inexact compared to modern methods. Today, measuring a peak down to the nearest inch means getting an instrument to the top, usually a GPS receiver. But climbing to the summit of some peaks, like those in the remote mountains of Alaska's Brooks Range, can be incredibly difficult, time-consuming and costly.
Nolan decided that determining the highest peaks in the Brooks Range would be the perfect way to test his new fodar setup, which uses a DSLR camera connected to a GPS unit to collect data for accurate 3-D maps of an area. “It’s not like no one could measure this before—it was just way too expensive to do so,” Nolan tells Misra.
Nolan's technology is similar to airborne lidar. While lidar can cost half a million dollars and requires a twin-engine plane and a separate operator to use, Nolan says his fodar setup, which he plans to use to measure the mass of receding glaciers in Alaska, costs $30,000 and can be run by a pilot in a single-engine plane, according to a press release.
To put his fodar to the test, Nolan enlisted the help of Kit DesLauriers, one of the world’s greatest ski mountaineers and the first person to ski down the Seven Summits, the seven highest peaks on Earth. Her job was to make it to the tops of Chamberlin and Isto and use a differential GPS system to measure their heights. At the same time, Nolan would use his fodar to map the peak, allowing them to test the accuracy of the new technology.
For DesLauriers, who made the climb with a photographer and another alpinist, it was a grueling 12-day expedition in the spring of 2014. “The GPS antenna, mounted to a steel post in my backpack, required a constant unobstructed view of the sky which forced me to find creative ways to adapt my usual ski carrying system while climbing,” DesLauriers says in the press release. “Instead of a normal rest stop to eat and hydrate, I used the rare moments standing still to note my location and time in a field journal so that Matt could have as much data as possible to compare our measurements. The process made climbing the peaks, which took on average a 10 hour summit push after a multi-day approach, more difficult but also more rewarding.”
The fodar method was accurate down to about eight inches, according to results, which were published in the latest issue of the journal The Cryosphere. The study reveals that Mt. Isto is the highest peak in the American Arctic at 8,975.1 feet. In a surprising twist, Mt. Hubley edged into second place with 16 feet on Mt. Chamberlin, which came in third at 8,898.6 feet.