Flashcards
GEO [#10] Snow Avalanches
Cards in this deck (17)
- 1Snow AvalanchesSudden downslope movements of snow and ice under the force of gravity that range in size and are similar to landslides
- 2Snow AccumulationThree types of snow accumulation include snowflakes, graupel and hoarfrost
- 3SnowflakesShape and size depend on the temperature and humidity. Become more complex with more humidity and more basic with less
- 4GraupelSuper-cooled liquid droplets that freeze on falling snowflakes that are dense and granular
- 5HoarfrostEssentially frozen dew created through the deposition of ice crystals on a surface directly from vapour in the air and are fragile
- 6Snow MetamorphismCan be caused by sintering (compaction without melting), sublimation (solid to gas) or freeze-thaw (melting)
- 7Faceted SnowProduced when strong vertical temperature gradient exists that makes the snowpack really prone to failure
- 8Types of Snow AvalanchesInclude loose snow avalanches and slab avalanches
- 9Loose Snow AvalanchesOccur in surface layers and grow wider as they move. Occur in fresh snow and are small and easy to predict
- 10Slab AvalanchesOccur when a coherent slab slides down a plane of weakness before breaking. A lot less frequent than loose avalanches but are more dangerous and hard to predict
- 11Slab Avalanche ConditionsNeed a slab of coherent snow that is resting on a weak layer, a steep slope and a trigger
- 12TriggersCan include natural or unnatural triggers that increase the driving forces of the snowpack. Includes new snow, rain, rockfall, earthquakes, increased temp, etc.
- 13ZonesInclude the starting zone (point or crown), track (pathway snow follows), and runout (where snow piles up) areas
- 14Mitigation of AvalanchesIncludes avalanche forecasting, static defenses, and artillery control program
- 15Avalanche ForecastingDigging a hole or shelf that allows you to see the layer of snow
- 16Static DefencesSnow sheds or avalanche chutes that funnel snow in a certain direction
- 17Artillery ControlShooting the snowpack to trigger avalanches and to bring snow downhill in a controlled way
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- Geology (Geology 202) Flashcards on GEO [#10] Snow Avalanches, created by Natasha Gidluck on 30/03/2019.
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- Natasha Gidluck
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