Avalanches

Avalanches are sudden, the warning signs are almost always numerous before they let loose. Avalanches kill more than 150 people worldwide each year.
Many avalanches are small slides of dry powdery snow. Disastrous avalanches occur when massive slabs of snow break loose from a mountainside and shatter as they race downhill. These moving masses can reach speeds of 80 mph within about five seconds. Avalanches are most common during and in the 24 hours right after a snow storm. Storminess, temperature, wind, slope steepness and orientation, terrain, vegetation, and general snowpack conditions are all factors that influence whether and how a slope avalanches. Different combinations of these factors create low, moderate, considerable, and high avalanche hazards.

Tornadoes

Tornadoes are vertical funnels of rapidly spinning air. Their winds may top 250 miles mph and can be 50 miles long. Tornadoes are born in thunderstorms.
These violent storms occur around the world, but the United States is a major hotspot with about a thousand tornadoes every year. A tornado forms when changes in wind speed and direction create a horizontal spinning effect within a storm cell. This effect is then tipped vertical by rising air moving up through the thunderclouds. Tornadoes' distinctive funnel clouds are actually transparent. They become visible when water droplets pulled from a storm's moist air condense.

On the wizard of oz, dorothy's house gets moved to oz by a tornado and this is true buildings can be moved by a tornado but I'm not sure they'd go to Oz!

Hurricane Katrina

On August 28th, 2005, Hurricane Katrina hit the southern coast of the United States with devastating effect. It was reported that more then 1,800 people lost there lives, and more then $81 billion dollars in damages occurred.
As a result, efforts to assist those effected by Hurricane Katrina still continue, as those effected by the terrible hurricane continue to work to regain the health and livelihood that they had before the storm. It was the sixth strongest storm ever! Winds reached speeds of 175 mph!
Hurricanes form from hot air forming of the ocean and get stronger as they go along.

What is a Natural Disaster?

A natural disaster is something that occurs naturally, from mother nature. Examples of theese are floods, earthquakes, volcanoes, tornadoes, sandstorms and hurricanes. Natural disasters can ruin peoples lives. Natural disasters happen all the time and they give many people inspiration for films and books for example 'The Wizard of Oz' is based on a tornadoe making Dorothy's house falling on the wicked witch of the east and killing her. Natural disasters also inspire photographers for example on 'Americas Next Top Model' they did a photo shoot acting as natural disasters. Some of the natural disasters they acted out was a heatwave and a tsunami.

2004 Indian Ocean Tsunami

The 2004 Indian Ocean earthquake was an undersea earthquake that occurred on December 26, 2004. The earthquake was caused by a tectonic plate sliding under another one and pushing it up causing an earthquake. This triggered a a devastating tsunami along the coasts of most land bordering the India Ocean, killing more than 225,000 people in eleven countries. Waves rose up to 30 meters high. It was one of the deadliest natural disasters in recorded history. India, Sri Lanka, Indonesia, and Thailand were the hardest hit.
With a magnitude of between 9.1 and 9.3, it is the second largest earthquake ever recorded. Over 7 billion dollars were donated to help the affected people of the tsunami. The tsunami itself is given various names, including the 2004 Indian Ocean tsunami, Asian Tsunami, Indonesian Tsunami, and Boxing Day Tsunami.

http://news.bbc.co.uk/1/hi/world/4136289.stm