Weak Cornices.

7th March 2009

The section of cornice which collapsed yesterday, with the debris in the background.

One section (further away) collapsed, while the other (foreground) section cracked, and settled a bit, but did not release. This failure was caused by stepping onto the location that this picture is taken from. When cornices are as weak as this, sometimes just approaching them can cause their failure. Other hill goers reported similar behaviour yesterday.

Yesterday there were some large cornices noted on Aonach Mor. This one collapsed when I skied a little too close. A climber was injured in Coire an Lochan, when he fell off when trying to surmount one other these cornices. Although the cornices were very unstable, the snowpack on the slopes below seems more stable. This cornice collapse failed to release the slope below. As the avalanche report indicates general snow stability, rather than specific cornice collapse hazard, a category 3 rather than a category 4 hazard rating was issued (although the cornice hazard was mentioned in the text).

Today the weather was very different with rain at all levels. Although all the cornices we observed today were still intact, but it wont be long before they begin collapsing due to the mild conditions. Also the stability of the large quantities of windslab about, will be dreceasing in the rain. All in all, an unpleasant, and potentially dangerous afternoon on the hill. However, a freeze is forecast for tomorrow, which will improve climbing conditions , and make travel around the hill alot easier.

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