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Roger Weller, geology instructor
by Casey Carillo
The Wellington, Washington Avalanche
This is a map of the Wellington Avalanche and the path that it took.
An avalanche is created when there are forces pushing against a slope. There is friction on the slope that is then released when gravity pulls down the snow particles creating the avalanche. During a snow storm the particles are either bonded together or locked together, this then creates layers of snow that are denser than other layers that do not have bonded or locked particles. During a snow storm whenever the temperature changes or the wind shifts, it has an effect as to how the snow settles or new layers are created. The stronger the bond that the layer has, the less likely it is for an avalanche to occur through those layers. But the weaker the bond is between the different layers of snow, the higher chance of an avalanche occurring.
Now when a snow storm begins to pile up on layers of snow with weak bonds this is where the problem occurs. The weight of the new snow causes the forces of gravity to push on the layer and eventually break the bond. Even the slightest force of a skier or even a snow machine can trigger the avalanche. With forces from previous instances the amount of pressure becomes unbearable on the weaker layers causing the avalanche to form.
This is an example of a loose avalanche.
There are two different types of avalanches; loose avalanches and slab avalanches. Loose avalanches occur on slopes where snow has lost its ability to be on the slope due to the lack of cohesion between the snow and the mountain or hill. When the avalanche occurs, the loose snow tumbling down picks up more and more snow to create an even bigger avalanche. Loose avalanches have a tumbling affecting gathering more and more snow. This type of avalanche usually occurs on slopes of thirty five degrees or more and this avalanche usually involves the top layers of the snow pack.
This is an example of a slab avalanche.
Slab avalanches occur when a weak layer from the snow pack fails and the cohesive layer above separates from the rest of the snow back and then flows down the mountain. The layer that remains acts as a unit and forms a slab of thick, packed snow that flows down the mountain. As this slab avalanche travels down the slope it then collides with other objects and rolls over the land picking up anything in its path. Then the avalanche is broken down into smaller pieces and by the end it is just a bunch of slab pieces all over the place.
This is an outline of where the avalanche happened.
On March 1, 1910, the town of Wellington in Washington was shook, literally. Snow was piling up dramatically that day, with over twenty feet up snow surrounding the small town. All of the sudden the weather shifted, from snow and sleet to rain. The thunderstorm was loud and booming. Lighting struck following by a loud booming thunder that shook a fourteen foot hill full of snow. This then created an avalanche, killing ninety six people.
This is the damage that was left behind.
The avalanche that hit the small town of Wellington, Washington was a slab avalanche because snow added up from a horrible blizzard and then broke into different slabs that hit the town. There was a span of about nine days in February where there was a nonstop snow storm, more like a blizzard. On February 28, 1910, the blizzard in the town of Wellington turned into a rain and warm wind storm. On March 1, 1910 around one o’clock in the morning a slab of snow broke loose from the side of a mountain during a thunderstorm and a ten-foot high mass of snow, half a mile long and a quarter of a mile wide, fell toward the town. The avalanche missed the Bailets Hotel, which was also home to the town’s general store and post office, but hit the railroad depot. All of the passengers and crew were asleep aboard their trains and as the avalanche hit, the impact threw the trains 150 feet downhill and into a river valley. As a result from this ninety six people were killed and only twenty three passengers survived from the train because they were immediately helped by employees from the hotel. Because the town of Wellington underwent horrible forest fires in the summer prior to the avalanche so that meant that there was less terrain to get in the way of the avalanche. There were no trees and other types of plants to block anything that would try to stop the avalanche.
The town of Wellington eventually changed its name to Tye during October of 1910 because of the association of the horrific avalanche that came with that name.