Tornadoes are rapidly spinning columns of air that occur in much of the United States, particularly in the Midwest, an area known as Tornado Alley. They appear as funnels winding from the clouds down to the ground. These “twisters” can cause many forms of damage to the area in which they strike, as well as serious injury or death to the people nearby.
Depending on its strength and wind speed, a tornado’s damage to man-made structures can vary. The mildest of tornadoes can break windows or knock down billboards, while stronger storms may rip off roofs or walls, lift mobile homes, or even wipe out entire swaths of neighborhoods. The strongest tornadoes have been known to bend skyscrapers and pull asphalt off of roads. The cyclones can throw automobiles and other large objects, which may cause further damage to structures.
While mild tornadoes may do nothing more than snap branches off of some trees, strong ones can be devastating to vegetation. Moderate tornadoes are capable of uprooting smaller trees, or breaking them in half. Some storms can wipe out larger trees as well, and in extreme cases, the wind and projectiles can demolish entire forests or wooded areas. This habitat loss can lead to the death of many animals, and the lack of trees causes increased erosion in the area.
A ground swirl is one of the most common indications that a tornado has passed through an area. The rotating wind of a tornado can cause wide, circular indents or dust patterns on the ground. These patterns are also known as cycloidal marks. The marks are sometimes analyzed by storm experts to determine the magnitude of the tornado that has passed through. Wider circles and deeper rifts in the ground tend to correspond with stronger storms.
In addition to simple damage, tornadoes can cause a variety of types of pollution. They coat areas with dust from other regions, and can cause toxic chemicals to leak from vehicles or factories. Both of these effects can kill local plants and upset the ecological balance. In addition to the trees that are toppled by the powerful winds, many animals can be swept away or crushed beneath debris. It can take years for habitats to recover from such a severe disturbance.