New Terrain Open at the Lake

After months of intensive control work and less-than-ideal cooperation from this winter’s ¬†weather, the Lake Louise avalanche control department has been able to open a couple of marquee pieces of terrain on the backside.

First to have its gate cracked was Fallen Angel (ER 6), off of the top of Paradise chair. A good part of the run was skiable long before it opened, but the narrow chokes through rocks near the top weren’t holding enough snow to allow the run to open. Recent snowfall changed all that, and the gate was peeled back for the first time this season.

Next on the list is a much more visible piece of double black-diamond real estate – Upper ER 5. This area needs alot of things to go right before it can be considered for opening, and like ER 6, the stars finally aligned and Upper ER 5 opened on Sunday.

One of the things that makes Upper ER 5 such a tricky place to open is the fact that it is a very complicated piece of terrain, with rocks, cliffs, gullies, and cornices requiring diligent and meticulous avalanche control. Especially in a season like this, the control team wanted to ensure that every square metre of the slope received control work, whether in the form of ski cutting or explosives. To paint a bit of a picture of the work required, Upper ER 5 this season has seen 69 single explosive shots and 33 double (“nukes”), as well as 13 avalauncher rounds and hundreds upon hundreds of ski cuts. Only after all of this work and observation did the control team feel confident that the terrain could open.

Those who spend any amount of time skiing Upper ER 5 will already have seen that some areas do not stand up to traffic that well, specifically at the entrance off of Paradise Bowl and through the narrow chokes at the transition between Upper and Lower ER5. As long as they remain viable ski lines, however, the run will remain open, avalanche conditions permitting.

This morning at Lake Louise it’s snowing lightly, and forecasts are calling for some more snow Thursday and Friday – let’s hope they’re right!

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ER 6 Almost Ready to Go

In the few weeks since the big storm that left over 60cm of new snow on the mountain, the avalanche control teams have been busy trying to get some more terrain open, proving again that they don’t¬† necessarily need new snow to keep busy. Even in periods of low to no snowfall the teams keep busy by concentrating on yet-to-be-opened terrain. Whitehorn II B & C Gullies opened last week, and ER 6 (Fallen Angel) is getting close, too.

Having a piece of terrain like ER 6 ready to open to the public is the result of weather and the amount of time the avalanche control teams have spent in there. The forecaster must be completely confident that all avalanche hazard has been removed, and that confidence comes from many weeks and months of explosive use, ski cutting, and observation. With some more snow in the forecast, ER 6 opening day is hopefully not far off.

So – how are the conditions in ER 6? The short answer is “variable’, but that probably doesn’t paint that detailed a picture. The main open areas of the slope are nicely compacted, mainly as a result of the avalanches that have run over them in the course of control work, packing down the snow that didn’t get cleaned out. The snow is suprisingly supportive, unless you get too close to any rock features or other traditional weak spots, which are generally soft and uncompacted facets. Facets are a type of snow crystal that forms when there is a strong temperature gradient, or in other words, shallow snow and cold temperatures. Areas around protruding rocks have less snow, and are less able to deal with a large temperature difference between the air and ground (see a previous post for more temperature gradient talk).

Yesterday, we went into ER 6 with two nukes, which is our term for two regular bombs taped together, and two sticks of bamboo. Rather than lob the shots onto the slope like usual, we stuck a bamboo pole in the snow, then taped the nuke to the top end. This is an air blast, which produces a different sort of load on the snowpack than a shot in the snow would. An air blast, while not penetrating as deeply into the snowpack as a thrown shot, covers a wider area, so if you’re only concerned about the top layer(s), an air blast is the way to go.

Air blasts are useful only if you’ve already determined the stability (or not) of the snowpack with ground shots and ski cutting. In other words, you only worry about the top layers after you’ve dealt with the rest of the snowpack. We didn’t get any significant results from either of the air blasts, so our confidence increased even more. Most of the slope is in skiable shape, but there are a few narrow parts where rocks have weakened the snowpack, and likely wouldn’t survive beyond the first few skiers to ski the run. A combination of new snow and some more skier traffic (those doing the control work) should make ER 6 good to go.

The first photo below shows a control team member attaching a nuke to a stick of bamboo. Because the shot is in the air rather than in the snow, the sound of the blast is much louder, so we’ll generally retreat a little farther away to await the explosion. As shown in the second photo, the poor bamboo doesn’t fare all that well!

Setting up an air blast in ER 6.

Setting up an air blast in ER 6.

Bamboo - after.

Bamboo - after.

As our team was controlling ER 6, another was making their way down the ER 5/6 ridgeline to control Upper ER 5 and the Kiddies Corner area. This is a longer route that requires the team to make their way on foot over rough, rocky terrain and down a steep ridge. We wanted to get these areas controlled as soon as possible so that the surrounding back side terrain could open without too long a delay. For these routes, patrollers will ride Top of the World chair, then take their skis off and walk up to the top of Paradise chair and the start of the control routes. This is much faster than skiing to and riding Paradise chair.

The photo below shows a control team nearing the bottom of the steep part of the ER 5/6 ridge, just above a slope on ER 5 called the Big Kahuna (not visible in photo, but visible from Paradise chair).

ER 5/6 Ridge.

ER 5/6 Ridge.