Galloping Glaciers and Other Slippery Matters

We had a close squeak in this research neighborhood the other day. In its frantic need to cut costs, the University of Alaska Fairbanks proposed doing away with the Department of Geology and Geophysics, with special budgetary-axe attention to the section commonly called Snow, Ice, and Permafrost. Cool heads prevailed , however, (with vociferous help from some hot-under-the-collar students, and telephone calls and faxed messages from around the United States) and the department stays...so far.

Mind, I wasn't much surprised by the proposal. It's the sort of thing you can expect when people get to working so hard on a problem they forget to look out the window once in a while. Hereabouts the view usually includes snow and ice, and it always holds geology.

Sometimes the combination provides more drama than one might expect. For example, though everybody usually thinks of glaciers as very slow-moving objects, Alaska and the adjacent Yukon Territory have an uncommonly high number of glaciers that sometimes move swiftly.

Members of the almost-cut university department have studied several of these surging glaciers for years, in conjunction with researchers from the Alaska Division of Geological and Geophysical Surveys and the U.S. Geological Survey. According to the Geophysical Institute's Carl Benson, one of my preferred sources of information on matters glaciological, Austin Post of the USGS is the person credited for proving a pioneering insight about surging glaciers, which is that they shift to high-speed sliding according to their own cycles in time.

One of Post's particular fields of interest is Alaska's coastal glaciers. He spent some time surveying and observing Variegated Glacier near Yakutat, which was known to surge periodically. From historical accounts and reports by the Native people of the area, Post knew that Variegated Glacier took off downhill about every 20 years. He and his colleagues studied patterns visible in the local terrain affected by the glacier's movement, paying particular attention to the lateral and terminal moraines---the piles of rocky debris shoved up by the moving ice to the sides and at its downstream end.

Thanks to the historical record and interpretation of the patterns in the terrain, the scientists were not caught unawares by the glacier's surge in the 1960's, and the Geophysical Institute's Will Harrison, together with colleagues from the University of Washington and California Institute of Technology, predicted the timing of its surge in the 1980's within months; they also studied it intensively before, during, and after the surge. This proved the most complete understanding of the surging glacier phenomenon to date (something the media downplayed at the time, probably because reporters were surprised by the glacier's sudden speedup---as were some dolphins caught in a glacier-dammed lake that had been a fjord).

USGS researchers still predominate on the teams studying the surging glaciers near the coast, such as the Bering Glacier southeast of Cordova. That huge expanse of ice shifted into high gear very recently, but the researchers had studied the patterns its movements left in the terrain and knew when it was likely to surge, to within a few years.

Harrison and his Geophysical Institute coworker Keith Echelmeyer, have concentrated more on surging glaciers in the Alaska Range, such as the Peters and Black Rapids glaciers. Black Rapids is my personal favorite, not only because I once fell into it (a fortunately narrow crevasse claimed me only hip-deep, and I was well roped up to fellow glacier-climbers) but because it's the first one UAF researchers studied.

Paleontologist Otto Geist had to move his tent several times as the glacier advanced upon the campsite.

That was in the winter of 1936-37, when Black Rapids was known as the Galloping Glacier. It advanced about three miles in three months, and came within half a mile of the Richardson Highway. The best estimate of the glacier's surge cycle is around 60 years, so it's just about due to gallop again. Ah yes, I'm glad the university didn't cut that department!

(And, by the way, though this is my last regular column, the university didn't cut me either. I've actually been retired for some time, as well as working part-time for the University of Alaska Press; these articles deserve and need more time, which Ned Rozell will be providing in the future. Thanks. It's been fun!)