Volcanoes A volcano is a mountain that opens downward to a pool of molten rock below the surface of the earth. When pressure builds up, eruptions occur. Gases and rock shoot up through the opening and spill over or fill the air with lava fragments.

Earthquake Earthquakes are the shaking, rolling or sudden shock of the earth’s surface that usually last less than one minute. They are the Earth’s natural means of releasing stress. More than a million earthquakes rattle the world each year and are most common on the West Coast.

Wildland fires are uncontrolled fires that spread quickly igniting brush, trees and homes. They can occur anywhere, but are most common in forested areas during the summer and fall months. Firefighters put out wildland fires by digging a fireline (strip of land where all brush and debris are cleared) or dropping water and chemicals from planes that smother the flames.

A tornado is a violent rotating column of air extending from a thunderstorm to the ground that can destroy large buildings, uproot trees and hurl vehicles hundreds of yards with wind speeds of up to 300 mph. Tornados form when warm, moist air and cool, dry air meet and create instability in the atmosphere.

A hurricane is a huge storm! They gather heat and energy through contact with warm ocean waters. Hurricanes rotate in a counter- clockwise direction around the “eye,” which is the center of the storm and the calmest part. When they come onto land, the heavy rain, strong winds and large waves can damage buildings, trees and cars.

A tsunami is a series of huge waves that happen after an undersea disturbance, such as an earthquake or volcano eruption. The waves travel in all directions and 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 and can cause a lot of destruction on the shore.

A flood happens during heavy rains, when rivers overflow, when ocean waves come onshore, when snow melts too fast or when dams or levees break. Flooding may be only a few inches of water or it may cover a house to the rooftop. Floods that happen very quickly are called flashfloods. Flooding is the most common of all natural hazards.

Drought is a long period of dry weather where less than normal or no precipitation falls. When drought occurs, there may be low water in streams, rivers, lakes and ponds and plants begin to brown and dry out.

Temperature extremes are very high or low temperatures. Extreme heat is called “heat waves,” which is a period of unusually high temperatures typically 95  F or higher. Extreme cold is called “cold snaps,” with temperatures usually falling below 5  F.