Catastrophic Events

What is a catastrophic event? A catastrophic event is a natural event that causes dramatic changes to living and non-living parts of the ecosystem

THUNDERSTORMS/FLOODING Result from the rapid upward movement of warm, moist air Occur inside warm, moist air masses and at fronts Effects: - Damaged homes, roads and bridges, contaminated water, drowning - Eroded land (some areas will have mudslides/landslides) - Drowned or washed away plants and animals, damaged habitats

LIGHTNING: Electric charges build up in clouds Occurs between regions of opposite electrical charge Effects: -Electrocutions causes burns or death, damage to homes, power lines -Destruction of ecosystem due to fires -Habitats destroyed, burns plants and animals -

TORNADOES: Violent, whirling winds that move counter clockwise Smaller than a hurricane Occurs during severe thunderstorms Effects -Can cause injury or death, destroys cars, buildings and property -Uprooted trees, increased erosion (high winds) -Destruction of habitats, kills animals and vegetation

On November 21, 1992, a series of tornadoes struck the Houston, Texas metropolitan area. Tornados are violent whirling winds that move counter- clockwise. Six tornadoes ripped through 9 subdivisions and some open land. Many roofs were removed from homes, walls were knocked down, and cars were overturned. Some homes were completely flattened by the strong winds that the tornadoes had created. Debris was found all over Houston. Trees and bushes were uprooted, and one wooded area had many trees torn from the ground and thrown up to 50 feet away. Dust and dirt were found piled up against houses, and many homes had broken windows due to rocks and debris being carried by the winds.

HURRICANES: A large, swirling, low-pressure system that forms over tropical (warm) oceans Warm, moist air rises and provides energy for the storm Effects: - Power outages, contaminated water, damage to roads, building and cars, injury from falling debris -Flooding, wind and water erosion, trees uprooted -Loss of habitats and food sources (land and aquatic), salt water kills freshwater plants -

Hurricane Katrina hit the gulf coast region of the United States on August 28 th, Among the affected areas, most severe devastation occurred in New Orleans, Mississippi and Louisiana. The severe devastating effects of hurricane Katrina were incurred mostly due to flooding. The contaminated floodwater that overflowed the residential areas caused long-term health effects on humans, animals and other inhabitants in the area. The flooding also resulted in pollution of groundwater reserves, which is a major water source for drinking purposes. The floodwaters from hurricane Katrina destroyed many homes and buildings that left people homeless or caused them to relocate. Many large items, such as boats and lumber, littered the streets that were once covered with several feet on water.

Droughts

EARTHQUAKES: Friction or tension between plate boundaries that builds up energy and begins to move Occurs along colliding or fracture plate boundaries. -Damage to property or life, broken gas lines (fires) and water lines, building damage -Splits (cracks) in roads, land and sink holes -Destroys habitat, loss of food sources -

On Tuesday, January 12 a 7.0 earthquake occurred under the island of Haiti leaving 230,000 people dead, 300,000 injured and over a million people homeless. One of the poorest countries in the world, Haiti’s people were severely impacted by the effects of the earthquake to their buildings and homes. Earthquakes are the shaking, rolling or sudden shock of the earth’s surface. Earthquakes happen along "fault lines" in the earth’s crust when friction built up in the tectonic plates is released. Earthquakes can be felt over large areas although they usually last less than one minute. Earthquakes cannot be predicted -- but scientists are working on it! Earthquakes can be strong enough to cause buildings to collapse and landslides to occur.

Other Catastrophic Events Landslides: Loss of life, weathers and erodes land, destroys habitats Volcanoes: Loss of life, ash blocks sunlight (prevents photosynthesis), air pollution, total destruction of land Tsunamis: Loss of life, destruction of property, pollutes ocean Human Activities: Destroy habitats, pollutes environment

On May 18, 1980, Mount St. Helens erupted in Washington state sending tons of ash and gasses into the atmosphere. It killed 58 people and caused more than $1 billion in property damage. 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. Volcano eruptions have been known to knock down entire forests. An erupting volcano can trigger tsunamis, flashfloods, earthquakes, mudflows and rockfalls. As lava from volcanoes cools, it creates new land. The islands of Hawaii were formed by volcanoes erupting.

A tsunami is a series of waves that can be generated by earthquakes, landslides, volcanic eruptions and large meteorite impacts. On December 26, 2004, a huge underwater earthquake caused a tsunami to generate and travel towards Indonesia. Waves reached heights of 100 feet and traveled as fast as 620 mph. These waves devastated Indonesia by wiping out villages, farmlands, and forest. Many ecosystems were destroyed beyond repair. Coral reefs along the coast no longer reside in the area because of the destructive waves. Farmlands and forest that used to provide food for the villagers have been ripped apart and washed away by flooding waters, including the livestock. Drinking wells were contaminated when the huge waves washed ashore. The spread of diseases and hunger were a threat to many villages. Debris that has been carried from miles away have caused a problem with the rebuilding process for Indonesia.

Additional Ideas Catastrophic Events speed up weathering, erosion and deposition. Ecosystems (habitats) must respond to change and maintain balance (succession). Animals are forced to move to a new location or adapt when their ecosystem is destroyed.