1986 Yukon Nuggets

Galloping glaciers

News that glaciers in Greenland are surging from their landlocked base to the sea brings to mind a similar phenomenon that has shaped the ice fields in the St. Elias Mountains. The Steele, Hubbard and Grand Pacific are glaciers known for erratic behavior.

From its source at Mount Logan in the Yukon, the Hubbard Glacier extends 76 miles to the sea, at Yukutat Bay in Alaska. In 1986 it advanced so rapidly that it trapped seals, porpoises, and other marine animals when a new lake was formed by the blockage of the bay. Hubbard’s surge was unprecedented in modern times, and is still underway. The glacier had been moving slowly for years. Now scientists say its current surge pattern was set off by the movement of other nearby glaciers. The Steele glacier is located on the north side of Mount Steele in the Yukon. It galloped for several months in 1966, and moved more than 1.5 billion tonnes of ice at about 50 feet a day. The Lowell is another surging glacier which usually ends at the edge of the Alsek river. Ice burgs calving off the glacier tumble into a wide spot in the river called Lowell lake. But every so often this glacier rushes forward dramatically. In the distant past it completely blocked the Alsek River, creating a massive glacial lake. In 1852 Lake Alsek was 100km long and about 100 metres deep, making it bigger than Lake Kluane. When the ice dam finally broke, it sent a wall of water down the Alsek River. Native stories tell of a group of people camped at the confluence of the Alsek and Tatshenshini Rivers who were drowned in the flood. If the town of Haines Junction had existed back then, it would have been either under water, or people living there would have had lakefront property. About 15km of the Alaska Highway would also have been submerged.

Studies have shown that surging glaciers seem to go for regular gallops regardless of whether the climate is cooling or warming. Surging, or for that matter receding, glaciers may also have geopolitical repercussions. For example, in the 1960s, the 25 mile long Grand Pacific Glacier, which flows into tar inlet just 70 miles from Skagway, began receding almost far enough to put its nose in British Columbia. I recall a local bush pilot and entrepreneur Leo Proctor stirring up a lot of excitement in the local business community by pointing out that if the glacier receded into B.C., Canada would then be able to claim a freshwater port in the Alaskan panhandle. At the moment the Grand Pacific still ends in Alaskan territory, but who knows what the future holds…

 

A CKRW Yukon Nugget by Les McLaughlin.