The Incredible Shrinking Glacier
August 10, 2018
Photographer: Patti Weeks
Summary Author: Patti Weeks
The Athabasca Glacier in Alberta, Canada, a jewel in the Canadian Rocky Mountains, is one of the most visited and most accessible glaciers in North America. It's one of numerous glaciers on the immense Columbia Icefield, which sits astride the Continental Divide — British Columbia on the west, Alberta on the east. Lying at the hydrographic apex of North America, the icefield has been called “the mother of rivers,” because its meltwaters flow to the Pacific, Atlantic and Arctic oceans! The Columbia Icefield, a remnant of the last 20,000 years of glaciation that covered most of Canada, is one of the 17 glacial areas adjacent to the 144-mile (232 km) Icefields Parkway (Highway 93) in Jasper and Banff national parks. Over time, glaciers advance and retreat, due to climate fluctuation. Retreat, however, is winning out worldwide — at an alarming rate — due to the rapid global warming over the past several decades.
By current measurements, the Athabasca Glacier is retreating up to 16.4 ft (5 m) per year. At its most recent advancement nearly 175 years ago, the glacier covered the entire area where the Icefield Centre parking lot is today, shown in the photo. (Compare the current appearance of the glacier in this photo with the 1844 photo on the informational sign.) According to notes from the CBC documentary “Geologic Journey,” geologists predict that at its current rate of retreat, the glacier will become an alpine meadow in one hundred years. Athabasca Glacier is just one of 2,500 glaciers in British Columbia and Alberta (most are in retreat). Note that there are an estimated 200,000 glaciers across the globe.
Described metaphorically as tombstone-like markers in an abbreviated report in NASA’s online reference Earth Observatory, 9 signs beside the rocky till ridges (moraines) left by the Athabasca Glacier indicate its location in various years, dating back to 1890. The second photo shows the sign marking the location of the glacier in 1935 and the glacier’s southern lateral moraine. Photos taken June 13, 2018.
Photo Details: SONY DSC-HX400V camera; 1/2000 sec. exposure; ƒ/3.5 aperture; ISO 80; 4.3mm focal length; 4.3-215mm ƒ/2.8-6.3 lens. Second photo: same except - 1/500 exposure time and ƒ/6.3 aperture.