Forest Fires
Forest fires, also known as bush or brush fires are most common in hot weather after prolonged periods without rain. They can be caused by the sun, lightning strikes, even stray sparks from train wheels, but are commonly due to human carelessness; discarded cigarettes and campfires.

Forest fires will devour dried out vegetation, rapidly engulfing thousands of acres at a time, destroying homes and anything else in their way. Firebreaks are set up to try and stop the fires progress by stripping land of anything that will provide fuel. Flying water tankers and helicopters drop thousands of gallons of water to suppress fires and chemical retardants are dropped to stop it spreading.

Fires can be unpredictable, changing course as the wind direction alters and can move at up to 30kmph (15mph). In 2003, there were over 85,000 forest fires in the USA, covering almost five million acres and costing over $1 billion to suppress.

Volcanoes
A volcano is caused by a weak spot in the earth’s crust allowing magma (liquid rock) to seep through to the surface. Jets of hot ash and hazardous gases can be thrown tens of kilometres into the air and lava flows, which are then propelled from the top and side vents of the volcano, can reach speeds of over 32kmph (15mph). The lava, which can burn at up to 1,200°C, incinerates everything in its path. Added to this, a pyroclastic flow can send an avalanche of ash and rocks at a speed of 220kmph (100mph).

When Krakatoa, Indonesia, erupted in 1883, it could be heard 5,000 miles away in Australia. The base of a dormant volcano provides rich soil and mineral deposits for the people who chose to live there. However in 1991, 38 people who had gathered to watch the eruption of Mount Unzen in Japan were killed because they couldn’t escape in time.

Eruptions have managed to cause large scale devastation. Pompeii, an ancient city in Italy, actually disappeared after the eruption of Mount Vesuvius in A.D. 79 and killed over 20,000 people. For hundreds of years the city lay buried under ashes and stone.

Lightning
When moist air rises in a storm cloud it produces a negative charge at the bottom and a positive charge at the top. Opposites attract and this produces an electrical discharge, between two clouds or a cloud and the ground. This is what we call lightning.

A bolt of lightning can reach 50,000°F - five times hotter than the surface of the sun. There are one hundred lightening flashes happening somewhere in the world every second, that’s about 8.6 million a day.

With that many, it is no surprise the myth that lightning doesn’t strike twice in the same place is in fact untrue. The Empire State Building was hit 15 times in 15 minutes during one storm. US Park Ranger, Roy C Sullivan, holds the record for being struck by lightning – he was hit seven times between 1942 and 1977.

To avoid being hit by lightning stay away from water, open spaces and metal objects. Sitting in a car is a good idea, as the metal chassis of the car carries the power around the occupants leaving them unaffected.