| |
| ||||||||||||||||||||||||||||
Proactive disclosure Print version   | |  Sir William Logan 1798 - 1875 Mount Logan
Mount Logan: highest point in Canada
Climbing Mount Loganby Martha Armstrong - 1992 It stands in the Yukon's St. Elias mountain range, towering over all other mountains in Canada, and all but one in North America. Its base probably covers more area than any other mountain massif in the world and it is named after the founder of the Geological Survey of Canada, Sir William Edmond Logan. The exact elevation of Mount Logan is still unknown. Current elevation measurements for the mountain go from 5950 to 6050 m. "Several different surveys have been done over the years," says the GSC's Michael Schmidt. "Depending on what their points of reference were and how the survey was done - there were different (elevation) values." In May, Schmidt will lead an expedition to climb Mount Logan and measure its exact height, this time using the Global Positioning System (GPS). "GPS is a satellite-based radio-positioning system being developed by the U.S. Department of Defence," says Schmidt. "Basically, the way the system works is that if you know the location of several points and you measure distances from an unknown point to the known positions, then you can figure out where the unknown point is " "We know where the satellites are, so we carry a very small portable receiver to the summit and measure the distances and the ranges from these satellites to this receiver over a time period of about four to six hours on two separate dates. This will give us a precise measurement of Mount Logan's elevation." The Mount Logan climb was suggested by Schmidt as a way to help celebrate the Survey's 150th Anniversary. It also coincides with Canada's 125th Birthday and the 50th Anniversary of the Alaska Highway. The Royal Canadian Geographical Society is organizing the climb, Logan '92, while the GSC, along with the Canadian Geodetic Survey and Canadian Parks Service, are partners in the expedition. Schmidt and his team of 12 will start the climb on May 11 following the same route used for the first successful ascent in 1925. The expedition will last about five weeks to allow climbers to acclimatize. Well known arctic scientist and project manager for the Society, George Hobson, says the climb's main purpose is research. "We're not climbing the mountain just because it's there... we're going to do some geology along the way." Some members of the expedition team will collect rock samples at regular intervals on the mountain in order to determine the uplift rate and the massif's age. By analyzing feldspar minerals in the rocks, the scientists will be able to tell approximately when the rocks cooled from a near-molten state. Determining the difference in cooling times between rocks collected at different elevations will help indicate how fast the mountain rose in the past. "It's one of the most uplifting hunks of rock in North America and perhaps the world," jokes Hobson. Schmidt explains that the St. Elias mountain range is one of the most tectonically active areas in Canada and uplift still occurs. "Just how much is it (Mount Logan) growing? That's one question to which we don't know the answer." The expedition team will also place a survey monument close to the summit, and perhaps several more on either side of a fault which bisects the massif. The monuments could become part of a regional network to monitor tectonic uplift and crustal movement. It will be some time before the results of most of this research are known, but one answer is expected by Canada Day. On July 1, the actual elevation of Mount Logan will be officially announced.
|
