Below is a fracture profile of the Widow Maker avalanche that occurred on 3/15/14. March 15th was the first sunny day after a 5 day storm deposited 4-5′ of heavy snow in this location.
Avalanche type: Hard slab
Avalanche problem: Deep slab
Trigger: Remote from snowmachiner(s) on ridgeline – no one caught
Angle: Average 40deg (broke up to the ridge on 30 deg terrain)
Crown depth: Average 4′, Max 9′
Dimensions: ~1200′ wide and running ~6-700′
Weak layer: .5cm layer of mixed forms composed of some 1mm faceted grains and 2mm surface hoar
Bed surface: very thick (20-80″) melt-freeze layer
This avalanche path is a wide planar slope with many smaller terrain features and narrow gullies. It ends in a fairly abrupt transition to lower angle terrain below allowing debris to pile up deeply in some areas. It is also, sadly, the site of a double fatality in 2008.
Between the occurrence and the time of the profile there has been around 6″ of new snow that covers the slide.
Please take a look at the other powerful photos sent in by the public on our observation page from the day the avalanche occurred.