Virtual Viewing
Inside Passage Audio Guide
Avalanche Slopes
Transcript
Avalanche slopes
Cruising through the Inside Passage in summer, it's common to see open slopes on the mountainsides extending downhill from the alpine. Low-lying vegetation such as alder, ferns and berry bushes cover the slopes, but these green expanses are devoid of large spruce and hemlock trees. These are avalanche slopes, swaths of forest bulldozed in late winter and early spring by tons of moving snow.
The mountains of Southeast Alaska are buried in snow as much as 20 feet deep in winter. Some areas with just the right slope angle are especially conducive to avalanches. The likelihood of an avalanche any given year varies: The condition of the snow when it falls and weather between snowfalls is as important as how much falls.
A typical avalanche buries the deposition zone of the avalanche slope under tons of snow. But life is waiting to emerge. Flexible alders, bent over and pinned to the ground, will leaf out and thrive as soon as the melting snow exposes them to the spring sun. Fern root balls, torn up and transported down hill, will sprout fiddleheads. Blueberry and salmonberry bushes reemerge and bloom.
In early summer, wildlife watchers scanning the slopes are rewarded with views of bear, deer and porcupine, which are drawn to the lush slopes to feed on emerging vegetation. Bears, hungry after their winter hibernation, are especially fond of the lower reaches, and mountain goats work the edges of the slopes at the higher elevations. Ravens flock to the slopes and the air is filled with the courtship songs of thrush, flycatchers and warblers.
By midsummer avalanche slopes are lush thickets of vegetation. Waterfalls spill crystal snowmelt down the mountainsides. It looks like an inviting meadow, but the view from a distance is deceptive. The warm, 18-hour days trigger explosive growth. The slopes are tangled thickets of overgrown vegetation, and game trails have become tunnels, teeming with mosquitoes and biting gnats called no-see-ums.