Avalanches By: Alex

Where my event typically happens Avalanches typically happen near snowy mountains, northern countries and cities.

How often does it happen? Avalanches can happen every day in certain places. They mostly happen in snowy, cold places. Avalanches are the most frequently happening natural disasters. Avalanches don’t happen in Florida but they do happen in Montana, North Dakota etc.

What structures, features are involved?  Cities and towns by the mountain  Trees and plants  Sometimes can rip the landscape out  Houses,buildings  Telephone lines  Cars and vehicles

When does it usually happen?  Mostly in the winter  In snowy places

What are the most extreme conditions that can happen with this disaster?  It can sometimes destroy cities and communities.  It can destroy landscapes and plants/natural features  Some huge avalanches can destroy everything in their path  Some cities don’t recover

What usually happens when an avalanche occurs?  A huge mass of snow comes ripping through the forest on a mountain  It destroys multiple cities and communities  Powerful avalanches can destroy snow barriers  Avalanches can destroy everything in it’s path

How do you measure avalanches?  First you can use the Rictor scale  Second you measure the feet of snow that the avalanche has produced  Finally you can measure how far it traveled  You can measure how wide the avalanche got

The after math After an avalanche occurs cities are sometimes be wiped out. Some people who live on the mountain try to escape and run away before it’s too late. After an avalanche cities are sometimes covered in ice and mud. (Sometimes rock.) Houses are left destroyed and families are left homeless.

Key terms  The Rictor scale is a machine that measures the seismic waves that can tell you how big the earthquake is going to be and how big the impact is.  A dry snow avalanche is when powdery snow and air that moves faster than 100 mph.  A wet snow avalanche is when a mass of wet snow moves slower than a dry snow avalanche.  In a slab avalanche is when a small portion of snow breaks off and rolls down the mountain.

Important facts  Avalanches can be prevented by dynamiting the area that is most likely to produce an avalanche.  There are 4 different types of avalanches  Avalanches occur when the snow underneath it losses it’s grip.  If it gets warmer the snow can melt and cause flooding.

Avalanche happening When an avalanche happens a thin layer of snow collapses and the snow starts falling.

Avalanche video

Sources   s05/jlrossi/results_and_analysis.html  H.J. McPherson “Avalanches” encyclopedia vol. A  Rob Shone “Avalanches and Landslides” New York Rosen publishing co  CNN.com