A Geohazard that can destroy whole towns.
Tornadoes: What are they?
How are these destroyers created?
1. Air Rotates Because of Wind Shear.
How the column of air begins to rotate is not completely understood by scientists, but one way the rotation appears to happen is when winds at two different altitudes blow at two different speeds creating wind shear. For example, a wind at 1000 feet above the surface might blow at 5mph and a wind at 5000 feet might blow at 25mph. This causes a horizontal rotating column of air.
2. Faster Spin Makes a Funnel Cloud.
If this column gets caught in a supercell updraft, the updraft tightens the spin and it speeds up (much like a skater's spins faster when arms are pulled close to the body. A funnel cloud is created.
3. The Funnel Rotates and Touches Down.
The rain and hail in the thunderstorm cause the funnel to touch down creating a tornado.
Why is it a Hazard?
Where can tornadoes most likely occur?
They occur mainly in a 10-state area known as Tornado Alley, stretching from Texas to Nebraska that also includes Colorado, Iowa, Illinois, Indiana, Missouri, and Arkansas. Tornadoes have to have the right atmospheric conditions to be created.
How are tornadoes measured?
Examples of the deadliest tornadoes in US History.
2. Natchez, Mississippi had a tornado on May 6th of 1840 which had a death toll of 317.