OUR TOPIC IS

TORNADO

WE ARE

+ 4971A004 Meady+ 4971A016 Peggy+ 4971A018 Vera

+ 4971A026 Charles+ 4971A042 Sophie

WHAT IS TORNADO?

+ A tornado is a violent, rotating column of air which is in contact with both the surface of the earth and a cloud or, in rare cases, the base of a cumulus cloud. Tornadoes come in many sizes but are typically in the form of a visible condensation funnel, whose narrow end touches the earth and is often encircled by a cloud of debris.

+ Most tornadoes have wind speeds between 40 mph (64 km/h) and 110 mph (177 km/h), are approximately 250 feet (75 m) across, and travel a few miles (several kilometers) before dissipating. Some attain wind speeds of more than 300 mph (480 km/h), stretch more than a mile (1.6 km) across, and stay on the ground for dozens of miles (more than 100 km).

+ Although tornadoes have been observed on every continent except Antarctica, most occur in the United States. They also commonly occur in southern Canada, south-central and eastern Asia, east-central South America, Southern Africa, northwestern and southeast Europe, western and southeastern Australia, and New Zealand

CATASTROPHE

When: 10th February in 2009Where: South-Central Oklahoma

Casualty: At least eight people were killed , 46 people with injuries

Destruction: The buildings collapse, the trees fallen down

BEFORE

AFTER

THE FACTS ABOUT TORNADOES

+ Strike quickly, little or no warning+ Appear transparent until dust and debris are

picked up or a cloud forms in the funnel+ Moves Southwest to Northeast+ Speed of a tornado is 30 MPH+ Accompany tropical storms and hurricanes+ Peak tornado season: Southern states → March through MayNorthern states→ Late spring through early summer

WHAT TO DO BEFORE A TORNADO

+ Weather radio, commercial radio or television newscasts

+ Look for approaching storms + Look for the following danger signs:

– Dark, often greenish sky – Large hail – A large, dark, low-lying cloud– Loud roar, similar to a freight train.

WHAT TO DO AFTER A TORNADO?+ Listen to local officials, and emergency

management personnel. + Stay away from downed power lines and other

harmful debris. + Check on the elderly and your pets. + Use a flashlight and not candles to inspect

damage. + Check for any gas leaks and turn the valves off+ Turn off electricity+ Watch for any loose debris that could fall.+ Take pictures

WHERE AND WHEN DOES TORNADO OCCUR MOSTLY?

+ America+ Spring and summer

WHY ARE THERE SO MANY TORNADOS IN AMERICA?

+ big plain

+ The Atlantic Ocean

+ The Pacific Ocean

+ The Gulf of Mexico

+ Middle latitude

LIST OF NORTH AMERICAN TORNADOES AND TORNADO

OUTBREAKS

THE END