Natural DisastersNatural Disasters

around the worldaround the world

What is a natural disaster?What is a natural disaster?

A natural disaster is the effect of a natural hazard.

There are many different types, such as volcanoes, hurricanes, tornadoes, earthquakes and floods.

VolcanoesVolcanoes

A volcano is caused when the tectonic plates that form the Earth’s crust collide and make a gap. This can allow magma to escape through the ‘mountain’

that the tectonic plates have created. In a composite volcano it is common for magma to explode, or burst out, whereas in a shield volcano the magma tends to ooze out.

A tornado is a violent, rotating column of air that destroys anything in it’s way. The most powerful tornadoes occur in the United States and a typical tornado only lasts for a few minutes. Tornadoes are unique – each one has it’s own colour, sound and shape. A tornado can occur at any time, but mostly happens between 3pm and 9pm.

TornadoesTornadoes

EarthquakesEarthquakes

• Although the ground we walk on seems solid, the Earth is actually made up of huge pieces of flat rock called tectonic plates. These move very slowly, and where they meet is called a fault. When the plates rub together, the movement forces waves of energy to come to the earth’s surface. This causes tremors and shakes – and this is what causes earthquakes.

HurricanesHurricanes

• A hurricane is a huge storm! It can be up to 600 miles across and have strong winds spiralling inward and upward at speeds of 75 to 200 mph. Each hurricane usually lasts for over a week, moving 10-20 miles per hour over the open ocean. Hurricanes gather heat and energy through contact with warm ocean waters. Evaporation from the seawater increases their power. Hurricanes rotate in a counter-clockwise direction around an "eye." The centre of the storm or "eye" is the calmest part. It has only light winds and fair weather. When they come onto land, the heavy rain, strong winds and large waves can damage buildings, trees and cars.

TsunamisTsunamis

• A tsunami is a series of huge waves that happen after an undersea disturbance, such as an earthquake or volcano eruption. (Tsunami is from the Japanese word for harbour wave.) The waves travel in all directions from the area of disturbance, much like the ripples that happen after throwing a rock. The waves may travel in the open sea as fast as 450 miles per hour. As the big waves approach shallow waters along the coast they grow to a great height and smash into the shore. They can be as high as 100 feet. They can cause a lot of destruction on the shore. They are sometimes mistakenly called "tidal waves," but tsunami have nothing to do with the tides.