Videos for avalanche practitioners
The videos posted to this channel since ~2015 are by Bruce Jamieson (snowline.ca) and colleagues. Some of the earlier videos on this channel are links to videos made by Bruce Jamieson and ASARC colleagues (UCalgary.ca/asarc). The links to all these videos can be shared freely and the videos used for any purpose, including commercially, provided the content and authorship are not altered.
Videos for avalanche practitioners
Communicating avalanche likelihood and probability
Starting with the likelihood definition and terms in the Conceptual Model of Avalanche Hazard (Statham et al., 2018), Scott Thumlert, Grant Statham and Bruce Jamieson present some ideas for improving avalanche likelihood and how it can be communicated. Presented at the Virtual Snow Science Workshop, October 2020. CC BY-ND.
Near crust faceting and slab avalanching
A technical video for avalanche practitioners and recreationists interested in avalanche science. The video outlines the formation of faceted layers near melt-freeze crusts, the persistence of these layers as potential failure layers for slab avalanches and some ideas on anticipating the resulting slab avalanches. Bruce Jamieson and Scott Savage, May 2020.
A more visual method for rating avalanche size on the D-scale
A video to start discussion about whether visualization will help us rate avalanche size on the D-scale. By Bruce Jamieson, Montse Bacardit, Ethan Greene and Ian Tomm. May 2020. Catalan and Spanish subtitles by Montse Bacardit. German subtitles by Thomas Exner. CC BY-ND.
Why does snow cool when melted with salt, and what does that have to do with avalanches?
When salt is added to snow, the snow cools because heat from the snow flows into concentrated salt water around the salt grains. The surprisingly large amount of heat required for melting (i.e. latent heat) contributes to avalanche formation in at least two ways.
Field observations vs snowpack tests: Which is best when?
In this study in recent winters, simple field observations correlated with the local avalanche danger better than snowpack tests. However, when Persistent Slabs dominate the Public Bulletin, snowpack tests may be helpful to supplement the field observations (they are better indicators of instability than stability). In spite of their limitations for selecting low risk terrain on the current day, snowpack tests may - over time - help recreationists become better at interpreting the bulletin and making low risk decisions.
Common snowpack tests
A brief how-to for common snowpack tests to locate and assess instabilities within the snowpack, presented by Mike Conlan. Start times of tests in this video are as follows: 1:32 Compression Test 5:06 Deep Tap Test 7:28 Extended Column Test 10:54 Rutschblock Test 14:48 Propagation Saw Test 18:48 Shovel Shear Test 20:49 Hand Shear Test 22:11 Concluding remarks on initiation, propagation, and limitations. Fracture character video: http://vimeo.com/30996756
Considerable avalanche danger: How much riskier is it?
Based on an ISSW 2009 paper by Bruce Jamieson, Juerg Schweizer and Cora Shea, the presentation uses an event tree, an expert survey of triggering odds, Canadian Accident data and some large assumptions to calculate the risk of death for a day of backcountry skiing at each of the levels of regional avalanche danger. The backcountry skiing risks are compared with the risks for a day of kayaking, a day of rock climbing and a day of mountaineering. During Considerable avalanche danger, backcountry skiing risk is about 10 times higher than when the avalanche danger is Moderate. The paper is posted at http://www.ucalgary.ca/asarc/system/files/RiskCalc_Issw09_Jamieson.pdf
Avalanche decision aids - the good, the bad and the disruptive
This video outlines some general advantages and disadvantages of avalanche decision aids. The advantages and disadvantages are general enough that – I hope – both backcountry recreationists and avalanche practitioners find something useful in this video. This video does not explain how to use any decision aids but does show four decision aids and identify where to find more information on them.
Here comes the sun, Purcell Mountains, 1-5 Feb 2012
Case study of the warming period and avalanche cycle, 1-5 Feb, 2012, Purcell Mountains. On Feb 1, the snowpack was a "loaded gun". Many avalanches including deep dry slab avalanches occurred the first two days during which direct short-wave radiation hit the fresh storm snow. A few days later, a similar level of direct short wave radiation did not release avalanches. Thomas Exner prepared this case study. Doug Latimer of Shadow Light Productions shot and edited the video. For more on forecasting solar warming of the upper snowpack, see https://vimeo.com/27930973 and http://www.ucalgary.ca/asarc/system/files/SWarm_Issw08_Bakermans.pdf
Fracture character in compression tests
This presentation video for advanced recreationists and practitioners identifies the five types of fracture character and shows the frequency of skier triggering on slopes that exhibited each type of fracture character in compression tests. Sound improved in January 2018.