Unit 4: Catastrophic Events

TEKS: Predict and describe how different types of catastrophic events impact ecosystems such as floods, hurricanes, or tornadoes.

Drought Main features: How it forms: Long periods of dry weather that last long enough to cause a water shortage How it forms: Interruption in the water cycle

Drought Most Likely to Occur: Impact on the ecosystem: Anywhere Drier months Impact on the ecosystem: Habitats Adds stress to ecosystems Landforms Cracked surfaces Other impacts Crop failure, livestock death, increased forest fires, energy production, and water shortages Heat Waves

Drought http://www.youtube.com/watch?v=tK-YATetLPI

Wildfires Main features: Spread slowly – burning material on the forest floor Spread rapidly – by the wind, which causes it to jump along the tree tops Help the fire spread Drought conditions Wind – gives it oxygen (fuel) and helps it move faster High temps Low humidity How it forms: Lightning – 1 out of 5 wildfires start this way Campfires Cigarettes Arsonists

Wildfires Most Likely to Occur: Impact on the ecosystem: Every continent except Antarctica Common in areas that experiences long hot, dry periods Impact on the ecosystem: Habitats Animals become endangered due to lose of habitat Economic losses of inhabited areas Landforms Watershed can have the vegetation burned off leaving it prone to erosion Can destroy millions of acres Other impacts Beneficial for maintaining balance; plants growth comes back quickly to burned area Affects air and water quality, soil composition, vegetation, & wildlife

Wildfires http://www.youtube.com/watch?v=CSB9pTurhi4

Tornadoes Main features: How it forms: Wind speeds of 250 mph or more Damage paths can be in excess of one mile wide and 50 miles long Form to the right or in front of the path a hurricane takes as it comes on land. How it forms: Violently rotating column of air extending from a thunderstorm From thunderstorms, which is where warm, moist air ahead of eastward-moving cold front. They mix creating hail, wind and tornados

Tornadoes Most Likely to Occur: Impact on the ecosystem: Winter and Early Spring, between the hours of 3pm to 9pm; but can occur anytime Tornado Alley: Central States and moves east Impact on the ecosystem: Habitats Destroy buildings and vegetation causing soil erosion Economic losses of inhabited areas Landforms Uproots trees Scour the soil off the ground down to the rock Other impacts Kills humans and animals

Tornadoes http://www.youtube.com/watch?v=x2ESfdhnsQo

Volcanoes Main features: How it forms: Pressure builds up from gases within the magma, then an eruption occurs Eruptions can be slow and fairly quiet or violently explosive How it forms: It is a vent in the Earth which allows molten rocks to escape to the surface

Volcanoes Most Likely to Occur: Impact on the ecosystem: Along the plates, near vents Impact on the ecosystem: Habitats Structural and functions damage of ecosystems Destroying animal life and habitats Economic losses of inhabited areas Could cause more greenhouse gases Landforms New land can be created After the eruption, soil becomes very rich, so plant life returning is highly likely Other impacts Hazards include hot, poison gases, lava flow, land and mudslides, earthquakes, fires, explosions, rockslides, flash flooding, and tsunamis The Ash can affect breathing, contaminating water supplies, collapse roofs, disrupt machinery, jet engine failure while flying

Volcanoes Impact on climate video Video Montage Volcanologist

Earthquakes Main features: How it forms: Shaking of the earth Waves travel outward from the source Speed of the wave depends on the source and the materials it has to travel through How it forms: Vibration of the Earth’s Surface that occurs after a release of energy in the crust Caused by volcanic eruption or movement of segments of the crust or the collision of the tectonic plates. The crust may bend and as the stress builds and exceeds the strength of the rock, it breaks and snaps into a new position

Earthquakes Most Likely to Occur: Impact on the ecosystem: Over tectonic plates and fault lines Near volcanos Impact on the ecosystem: Habitats Destruction of the habitats Standing bodies of water to disappear into cracks Economic loss Landforms Large cracks in the ground Land of either side of the fault can raise, lower, move away or toward each other Other impacts Liquefaction of the ground Landslides Avalanches Fires Tsunamis

Earthquakes http://www.youtube.com/watch?v=opsiKirDfdE http://www.youtube.com/watch?v=bJR8I_Vk5TU http://www.youtube.com/watch?v=Z7eABGpOHv8

Catastrophic Charades

Hurricanes Main features: How it forms: High winds Tornadoes Storm Surges as it approaches land Flooding from torrential rains Mudslides or landslides How it forms: Moist, Warm air above the ocean rises and cools forming clouds. The warm and cool air begins to spiral upward causing wind Considered a Hurricane when winds reach 74 mph or more

Hurricanes Most Likely to Occur: Impact on the ecosystem: East Coast Hurricane Season: June 1 to November 30 Impact on the ecosystem: Habitats Structural and functions damage of ecosystems Destroying animal life and habitats Economic losses of inhabited areas Landforms Uprooting trees and defoliating vegetation Other impacts Damage could take years to rebuild

Hurricanes http://www.youtube.com/watch?v=zP4rgvu4xDE or  http://www.youtube.com/watch?v=QDFK40UMotc

Tsunamis Main features: How it forms: A series of waves traveling 450-600 mph in open ocean waves travel outward in all directions As they approach land, waves get slower and taller The first wave is usually not the largest or most destructive The water pulls back before the waves arrive The waves come to shore as a rapidly rising, turbulent surge of debris filled water How it forms: Large ocean waves caused by the following: Earthquakes Volcanic eruptions Meteorite impact Underwater landslides

Tsunamis Most Likely to Occur: Impact on the ecosystem: During any season Areas of risk are less than 25ft. above sea level and within one mile of shore Impact on the ecosystem: Habitats Loss of habitat or human homes Flooding Extreme Damage Landforms Flooding of estuaries and rivers Other impacts Contamination of drinking water Fires from broken gas lines Drowning

Tsunamis Thailand tsunami Japan tsunami Tsunami 101

Floods Main features: How it forms: Over abundance of water in a lake, river, flood plain They can last a few minutes or months The amount of flooding is controlled by water build up, how porous the soil is, and the water already in the soil. How it forms: Overflowing of water onto normally dry land Intense or long term rain from storms, hurricanes, melting snow or ice

Floods Most Likely to Occur: Impact on the ecosystem: Anywhere Primarily Coast & Floodplains Impact on the ecosystem: Habitats Property loss or damage Total destruction of a habitat Landforms Washing out roads and parking lots Asphalt and concrete is not porous Other impacts Contamination of drinking water Destruction of crop and livestock

Floods Nashville TN flooding 2003 Flooding from Hurricane Katrina