Technical information, news, research, and opinion on avalanches, snow safety, and winter backcountry travel.

Friday, October 22, 2010

Union Creek

I keep dreamin', you'll be with me and you'll never goNickelback

This post is in memory of Kevin Carter, Devlin Williams, and Phillip Hollins.

February 2008
Almost three years ago I sat in a Seattle coffee shop and read an article in The Stranger. The sharp words pricked a nice hole in the warm bubble of what was an otherwise quiet afternoon: three snowboarders disappeared in Union Creek during early December, and they had not been seen, nor heard from since.

It was a La Nina winter, and you can bet snow was on my mind: I'd already visited friends in Revelstoke once during early January, and my upcoming travel plans included another trip to Revelstoke, followed by a trip to Banff to see my aunt and uncle.

So, I won't really get into what was going on in my life at that time, but I think massive changes sums it up quite nicely. In the past three months I had finally started to escape from a very dark hole, and I wanted nothing more than to stay in British Columbia and spend the rest of the winter climbing my way out of the awful black.

Not yet ready to head back to the States, I extended my trip and spent some time skiing near Valhalla Provincial Park. Sitting alone in my hotel room one evening, I realised that computer graphics techniques already provided solutions to the certain types of perception problems. We look at maps, and we get an idea about where we should and should not travel in general. But the computer can transform a map from merely useful to truly useful.

Theory of Relativity
In addition to incredible ease of access, the backcountry near Crystal Mountain is middle ground terrain. This sets up a classic middle ground perception problem because Union Creek has a rather benign appearance relative to high alpine terrain. In other words, you can drive to the trailhead, skin from the car, but you won't see enormous snowfields below savage peaks. Instead, as mountain terrain goes, Union Peak is really sort of small, steepish, and extensively gladed. To this point, there are plenty of places that seem safe..

In a typical scenario, the skier examines the choices in front of them and selects what 'appears' to be a safer option. A common equation is as follows: trading steepness for trees, or trading open slopes for tree covered slopes. However, safety is relative, and safer is not the same thing as safe. When avalanche danger is High, statistically speaking, the safer option might not actually be any safer at all. Without hard numbers, how do you know if you're really reducing or exposure or if you're just trading horses?

Can you identify ski runs that are safe during high avalanche danger?

You can examine the terrain from the air, and can you stare at contour maps all day long, but the fact of the matter is that the human mind just isn't very good at certain types of tasks. Computers are wonderful tools, and they are quite happy to help us cut through the clutter of our minds and tell us the truth.

Want to take a look at what the computer sees?

Union Creek
Union Creek is popular backcountry terrain east of Crystal Mountain Ski Resort. Union Creek contains COMPLEX avalanche terrain. In poor conditions, line-of-sight is limited and safe travel may be difficult for anyone regardless of skill level. Start zones in Union Creek are capable of producing large, destructive avalanches.

Required Skills: Expert route finding and expert snow stability assessment.

Visualization of terrain > 25 degrees and < 25 degrees. Avalanches often run into blue terrain.

Avalanche Terrain!

Terrain Trap!

Elements of avalanche terrain at Union Creek.

HistoryPeople have been killed by avalanches in Union Creek. Large soft-slab avalanches run during and after storms. Surface hoar formation is widespread in this drainage. Faceted snow often develops near ridgeline and rocks. Wind-loading occurs during high winds. Local skiers report 1, 2, and 3 foot crowns. ( Crown size of 30cm to 1m. )
Avalanche Starting ZonesMultiple avalanche starting zones are found below ridgelines.
Avalanche PathsChanneled and unconfined avalanche tracks are found throughout Union Creek. Avalanches move very quickly in confined tracks. On the east and north slopes, several large, poorly defined paths exist below large, open start zones. Numerous, small avalanche paths run through trees on all the slopes of Union Creek. Avalanches in these narrow, tree-lined paths are extremely dangerous.
Avalanche Runout ZonesA network of gullies forms overlapping runout zones at the bottom of Union Creek. This region is a complex, dangerous terrain trap. Other runout zones extend into forested areas.
ShapeConvoluted, with very frequent changes between concave and convex slope shapes.
Large Surface AreaTerrain in this drainage has a very large surface relative to its size on a map. Large amounts of snow accumulate throughout Union Creek.
Steep TerrainMuch of the terrain in Union Creek is very steep and avalanche prone. In many areas, more than 90% of the terrain suitable for skiing is between 30-40 degrees.
Open TerrainUnion Creek has large areas of open terrain.
ConfinedTerrainSome locations in Union Creek feature highly enclosed terrain.
Line-Of-SightSome locations in Union Creek have limited line-of-sight. You may not be able to see overhead avalanche terrain because of terrain features or trees.
Terrain TrapsUnion Creek has numerous terrain traps such as convexities, trees, depressions, and gullies. Computer modeling finds hundreds of terrain traps.
Safe AreasRidge areas are safest. Terrain on the valley floor, if below open terrain above, is not safe. Many of the avalanche paths in Union Creek are enlarging every winter. There are safer areas in the valley below thick expanses of trees that run to the ridgeline.
Exposure Time
Many ski runs and travel routes are exposed to avalanches for their entire length and offer no chance to reduce exposure. Less dangerous routes do exist, but require expert route-finding relative to the current conditions. Deep snow and steep terrain often make uphill travel slow and difficult.

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