catastrophic events
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Catastrophic Events. Wildfires. How it forms: 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 - PowerPoint PPT PresentationTRANSCRIPT
Catastrophic Events
Wildfires• How it forms:– 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
• 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
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
Volcanos• How it forms:– 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.
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• Liquefaction of the ground• Landslides• Avalanches• Fires• tsunamis
Tsunamis• How it forms:– Large ocean waves caused by the following:
• 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 5-90
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• Contamination of drinking water• Fires from broken gas lines• Flooding• Drowning
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=4cvgM56nMAE