1. Unit 4: Catastrophic Events

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

3. 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

4. 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

5. Drought

6. 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

7. 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

8. Wildfires

9. 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

10. 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

11. Tornadoes

12. 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

13. 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

14. Volcanoes
Impact on climate video
Video Montage
Volcanologist

15. 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

16. 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

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

18. Catastrophic Charades

19. 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

20. 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

21. Hurricanes
or 

22. Tsunamis Main features: How it forms:
A series of waves traveling 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

23. 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

24. Tsunamis
Thailand tsunami
Japan tsunami
Tsunami 101

25. 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

26. 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

27. Floods
Nashville TN flooding 2003
Flooding from Hurricane Katrina