Thursday, January 22, 2009

Backcountry update

Avalanche hazard remains a very real concern still despite a slowly strengthening snowpack. Although the probability of triggering the weak layer of facets deeper in the snowpack is declining, the consequences of triggering remain high; if triggered, this layer continues to produce large, widely propagating avalanches. The weakness extends pretty much from SE Alaska all the way to Utah through the coast and interior ranges.

Primary Concerns:

Deep Slab: It is still possible to trigger the December 6 facet/crust combo and the ensuing avalanche could be very large with potentially serious consequences. (Big chunks of hard slab the size of cars with you in the middle) This layer is beginning to show signs of strengthening which is a good sign, but it also makes it harder to predict if or where it could be triggered.

Continue to avoid likely trigger spots like steep rocky slopes, large convexities, shallow snowpack areas, and cross-loaded terrain.

Practice good safe-travel techniques and choose terrain with options to reduce your risk. Your best bet for decent riding is in sheltered north-facing glades where the snow remains cold.

All though far from Whistler worth noting is a fatal accident in Montana recently on Jan 18, 2009.

Snow depths at the accident site were highly variable; however, faceted snow crystals at or near the ground have been found on all aspects in this area.

The slope had been seriously tracked up before the slide occurred

A recent class 3 in Montana slid on the same type of facet layer

The victim was climbing a steep, north northeast facing slope on Crown Butte when he got stuck. While working to free his sled, it began tumbling down the slope. It tumbled 3-4 times before impacting a rock 50-100 ft below him. The slope then fractured about 75 ft above him. The resulting avalanche was estimated to be 300 ft wide and 1000 ft vertical. The crown height ranged from 2 ft to 15 ft, and the run out angle was 28 degrees. Link-->>

Some snowmobiling tips:

-Check your local avalanche bulletin. Canadian Avalanche association South coast
Link to site-->>

-Expose only one rider at a time on a slope, and don't stop in terrain traps. By stopping this one behavior we’d see avalanche fatalities plummet. Don't go and help your buddy unstick his sled at the top of their high mark you may be putting your own life at risk, and may be just the trigger the slope needs.

-Carry rescue gear and know how to use it, and make sure your buddy is capable of effecting your rescue. There’s nothing worse than going to an accident scene and finding someone dead from a shallow burial where a transceiver may have saved their life. In addition airbag backpacks are now available in Canada, and are worth looking into if your a serious enthusiast, statistics out of Europe suggest they greatly increase your chances of survival should you be caught.
Snowpulse backpacks
ABS backpacks

-Carry a Sat phone, or PLB. These devices will greatly assist you should you need outside help. Digital only cellular coverage is available in the general Whistler /Pemberton valley area only.

Sat phone (most useful)
Iridium Sat phones

Whistler SAR has PLB capacity and a receiver to home in on signals. The PLB must be registered, and sends signals directly to the nearest Rescue co-ordination center.(Victoria) It sends accurate GPS cordinates and also emits a homing frequency for local teams to pinpoint you position.
PLB 406Mhz

Allthough not as effective as a PLB this device sends a message via Satellite to a Texas monitoring center it will give approximate GPS co-ordinates.
Spot me beacon

-Avalanches are a matter of timing. There are certain times when the snow pack is stable and others when it’s quite unstable. Be patient and wait for things to stabilize. The most obvious signs of instability being recent avalanche activity , make sure you stop and look around for obvious clues.

-Access to the Garibaldi park should be checked with local ski patrol for current access routes.

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