Catastrophic Events
Wildfires
• How it forms:
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Lightning – 1 out of 5 wildfires start this way
Campfires
Cigarettes
Arsonists
• 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
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Drought conditions
Wind – gives it oxygen (fuel) and helps it move faster
High temps
Low humidity
Wildfires
• Most Likely to Occur:
– Every continent except Antarctica
– Common in areas that experiences long hot, dry periods
• Impact on the ecosystem:
– Habitats
• Watershed can have the vegetation burned off leaving it prone to
erosion
• Animals become endangered due to lose of habitat
• Economic losses of inhabited areas
– Landforms
• 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
Hurricanes
• 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
• Main features:
– High winds
• Tornadoes
– Storm Surges as it approaches land
– Flooding from torrential rains
• Mudslides or landslides
Hurricanes
• Most Likely to Occur:
– 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
Drought
• How it forms:
– Interruption in the water cycle
• Main features:
– Long periods of dry weather that last long enough to
cause a water shortage
Drought
• Most Likely to Occur:
– 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
• How it forms:
Volcanos
– It is a vent in the Earth which allows molten rocks to
escape to the surface
• Main features:
– Pressure builds up from gases within the magma, then
an eruption occurs
– Once an eruption, the eruption happened the earth goes
back to equilibrium
– Eruption can be slow and fairly quiet and violently
explosive
Volcanos
• Most Likely to Occur:
– 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
Volcanos
– http://www.youtube.com/watch?v=s2i4XS0Esks&playne
xt=1&list=PL49FAA74692D7AFD4&feature=results_video
Tornados
• 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
• Main features:
– 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.
Tornados
• Most Likely to Occur:
– Between the hours of 3pm to 9pm; but can occur anytime
– Winter and Early Spring – which has more strong, frontal systems
that form in the Central States and moves east
• Impact on the ecosystem:
– Habitats
• Destroy buildings and vegetation. Lose of vegetation can result in soil
erosion
• Any thing in its path
• Economic losses of inhabited areas
– Landforms
• Uproots trees
• Scour the soil off the ground down to the rock
– Other impacts
• Kills humans and animals
• Vegetation that withstood the tornado may grow in abundance in that
area which, in turn could hinder animal and plant interaction.
Tornados
• http://www.youtube.com/watch?v=x2ESfdhnsQo
Earthquakes
• 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
• Main features:
– Shaking of the earth; waves travel outward from the source
and the speed of the wave depends on the source and the
materials it has to travel through
Earthquakes
• Most Likely to Occur:
– Over tectonic plates and fault lines
– Near volcanos
• Impact on the ecosystem:
– Habitats
• Destruction of the habitats
• Large cracks in the ground, causing standing bodies of water to disappear
• Property damage and loss of life
– Landforms
• Land of either side of the fault can raise, lower, move away or toward each
other
– Other impacts
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Liquefaction of the ground
Landslides
Avalanches
Fires
tsunamis
Earthquakes
• http://www.youtube.com/watch?v=opsiKirDfdE
• How it forms:
Tsunamis
– Large ocean waves caused by the following:
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Earthquakes
Volcanic eruptions
Meteorite impact
Underwater landslides
• Main features:
– A series of waves that can travel 450-600 mph in open ocean
– In open ocean, Boats do not feel the waves because the wavelength are
several hundred miles apart and the amplitude is only a few feet.
– As they approach land, the speed deceases and the amplitude increases
(basically it gets slower and taller)
– From the starting point, the waves travel outward in all directions
– As the waves approach land, the time in between waves ranges from 590 minutes
– 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
Tsunamis
• Most Likely to Occur:
– 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
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Contamination of drinking water
Fires from broken gas lines
Flooding
Drowning
Tsunamis
• http://www.youtube.com/watch?v=5-zfCBCq-8I
Floods
• How it forms:
– Overflowing of water onto normally dry land
– Intense or long term precipitation from storms,
hurricanes, melting snow or ice
• Main features:
– 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 the amount of
water that builds up, how porous the soil is, and the
amount of water already in the soil.
Floods
• Most Likely to Occur:
– Anywhere
– Coast
– Floodplains
• Impact on the ecosystem:
– Habitats
• Paving the ground for houses
• Property loss or damage
• Total destruction of a habitat
– Landforms
• Roads and parking lots
• Asphalt and concrete is not porous
– Other impacts
• Contamination of drinking water
• Destruction of crop and livestock
Floods
• http://www.youtube.com/watch?v=4cvgM56nMA
E