News & Updates:
Like the website?
|
Glaciers - part 2
|
Articles In This Section:
|
||||
|
Icefield.—Two problems are provided by an icefield: Its crevasses are usually snow-covered and difficult to detect. Wherever this situation exists, the party must be roped, with a good interval between men, and should follow a route perpendicular to the crevasse system so that no more than one man will be, unsuspectingly, over the same crevasse. The second problem is that of maintaining route when, as frequently happens, a fog or blizzard settles down on the icefield. If weather threatens, route markers (willow wands 36 in. X 1/4 in. with red flag on which back azimuth may be marked) should be placed along the route, each succeeding wand being retrieved on the return as soon as the next one has been found. The skier should remember that a cloudless sky does not necessarily mean a fogless icefield later in the day, and that tracks may be either quickly melted in wet snow or quickly covered by windblown powder.
Hanging glacier.—An active hanging glacier can threaten a broad area beneath it, and should be given a wide berth. Its first sign of activity may be an ice avalanche. Icefall.—An icefall is to be avoided where possible. It is not static. Seracs may topple as the glacier moves, but they are often stable for long periods of time. If passage is necessary and seracs appear unstable, it should be swift, to minimize time of exposure, and silent, so that sounds of moving or falling ice may be heard and heeded. Members of the party should keep a weather eye on the ice cliffs above them. Crevasses.—These are the classical bugaboo of glaciers, and while often very interesting and beautiful, deserve their bad reputation. Even when not snow-covered, they may present a maze that requires time-consuming search for a zigzag route. In a gentle icefall they can close unpredictably, and, in an area under pressure that was supposed to keep them closed, one was known to open with an alarming report just three feet from a pitched tent. On snow-covered glaciers they may be too broad to be bridged and require long detours; snow bridges may be unsturdy-looking and adequate or deceptively the exact opposite; a bridge reliable in the morning may have softened and be ready to slough into its crevasse in the afternoon; the crevasse may be completely covered by snow, which may have settled into a hollow barely perceptible in poor light, or there may be so fresh a snow cover that the crevasse cannot possibly be detected, even by careful probing with the ice-ax shaft, until the curses are heard of the leader who has fallen into it (and who, if his curses are to be heard, must be roped and belayed). Bergschrund.—This crevasse is often a welcome sight, because it is the highest and last crevasse encountered on the ascent of a glacier; conversely, it is a discouraging sight if, as can happen, its upper lip is 40 feet high and overhangs (see the final page). It is usually crossable on a bridge formed by frequent snow slides from the neve above. Close watch must be maintained for falls of additional bridging material. A shoulder stand may provide all the leader needs to find purchase on the upper lip. The 40-foot, overhanging type might be climb-able with the aid of ice ax, crampons, ice pitons, and a tension belay; chances are, however, it was the wrong route. Snow curtain.—On this slope the mountaineer sighs with relief because the bergschrund is below, but he is mindful of the step-cutting job on the steep slope above him, and of the frequency of the recent avalanches needed to build and maintain his snow bridge over the bergschrund.
| ||||||
|
 Subscribe                       
Add URL - skimountaineeringsurvival.com Blog
Related terms you should consider: virginia skiing and skiing lessons - Also see exciting tour for good info. All Rights Reserved. - Site Map - Privacy Policy - Disclaimer - Terms of Use - Contact |
||||||
