Topic Tag: level 2

In Canada, one tool for sorting terrain and how complicated moving through pieces of terrain will be is the ATES. Terrain is categorized as Simple, Challenging, or Complex. Below is a video describing each terrain category.

The Avalanche Terrain Exposure Scale:

We are going to spend some time studying terrain and possible ski routes at the Sorcerer Lodge in Canada. The goal of this exercise is to gain familiarity with how to route plan for a new area. You will also gain familiarity with how use CalTopo and other resources. This activity is self paced. We will give you a task to complete and then will offer a video explanation on the answers we came to with each question. Enjoy!

Below you will find links that we cover in the introduction video and that you will need for this exercise.

https://sorcererlodge.com/terrain-overview/

https://caltopo.com/m/65B2

https://www.avalanche.ca/

http://www.wisegoat.ca/

STABILITY TESTS

The Extended Column Test is a commonly used stability test. With this test, you are looking to see how much force the column takes to fail and if the failure propagates across the whole column.

Here’s a how to.

Another stability test that is often used is the compression test.

Here is how to do the compression test.

REMEMBER: Stability tests are just one piece of the puzzle. Don’t make a decision based on just one snowpit or one stability test. These tests should be used in conjunction with other information. Have you seen recent avalanche activity? Has there been any cracking or collapsing? What is the season history and the current avalanche problem(s). And if there is ever any confusion with test results or how they fit in to the big picture, choose simpler terrain.

When the temperature is above 0° C, the snowpack begins to move through a melt-freeze metamorphism. This means that the snowpack is often going through swings of being very strong when it’s frozen and very weak when it’s not frozen each day.

Here are some things to think about.

And here is a deeper dive into wet snow.

It is important to ask different questions when you are dealing with wet snow and wet snow avalanche problems. These questions include:

Did it freeze last night? How thick did it freeze? How is the new snow affecting the old snow? How wet is the snowpack?

CONCLUSION:

How do facets form on the surface of the snow? What drives growth of depth hoar? How does surface hoar form? In the following two videos, Jake will cover a variety of faceting processes including near surface faceting. He will also cover surface hoar growth.

Faceting can also occur on the surface of the snowpack. Faceting that happens at the top of the snowpack, rather than at the bottom of the snowpack is called Near Surface Faceting. There are 3 different near surface faceting processes – Diurnal Recrystallization, Radiation Recrystallization, and Melt Layer Recrystallization.

The following video will cover the faceting process, depth hoar formation, and near surface faceting.

SURFACE HOAR GROWTH AND DEVELOPMENT.

Surface hoar is winter’s dew. It is formed under cold, clear, calm conditions. It is not a problem on the snow surface, but once it is buried, it often forms a weak layer.

In the following video series, Jake Hutchinson talks through a variety of snow metamorphism processes. These videos take a deeper dive into snow formation and metamorphism that will help you build a solid foundation of understanding of snowpack development and evolution.

ROUNDING is a metamorphic process that can happen within the snowpack. Rounding occurs when there is a small temperature gradient in the snowpack. Rounding is a strengthening process.

The AM form is a 3-page document. Don Carpenter is going to walk you through an exercise, completing an AM form, based on information from a day in the backcountry around Jackson, WY. In this three part video series, Don will present the information he uses to complete the forms. There will be downloadable links to each page of the AM form, as well as to the resources that Don presents. Take the time to complete each page and then check your completed AM Form against the answer key.

PART ONE RESOURCES:

PART 2 RESOURCES:

Checking the avalanche forecast and understanding the avalanche hazard rating for the day is important. It is also important to dig deeper and understand what, if any, avalanche problems are forecasted for the day.

Understanding avalanche problems can aid in more effective route planning. If there is a forecasted wind slab problem at upper elevations on ENE aspects, you can plan a route that avoids these areas, or you can plan a route into this zone with a backup plan for if the problem is present.

Let’s take a deep dive in to Avalanche Problems with Don Carpenter.

Now let’s talk about the specific problems one by one.

And now let’s spend some time discussing how avalanche problems fit in to the forecasting process.