Transcript Catastrophic Events

Catastrophic
Events
Catastrophic
Events
 Catastrophic Event
–Any event naturally occuring or
caused by human action that:
 Causes severe damage to the land
 Endangers human life or causes loss of
life
 Speeds up the effects of erosion and
deposition
–Also known as natural disasters
Tornadoes
High speed rotating winds often greater
than 250 mph forming a funnel shaped
cloud
• Extreme low pressure causing materials
to be sucked up into the funnel like a
vacuum
•Ranked from F-0 Tornado (light damage
such as broken tree limbs)
to F-5 Tornado (total demolition of and
area including concrete sucked up from
the ground)
•Causes erosion
•
Droughts
Long periods of time with little to
no significant precipitation
What other disasters can this
cause?
Famine, Dust Storm, Erosion of soil.
Wildfires
•Caused by lighting or careless
handling of fire
•What conditions could make fire
more likely to occur?
•Lighting, drought, high winds
•What other disasters could this
bring?
•Floods, Erosion, smoke blocking out
sunlight
Floods
 Occurs when a body of water
overflows its normal boundaries
 What disasters could cause a
flood?
 Caused by heavy rains from
hurricanes or thunderstorms
 melting snow or ice
 Causes damage to home, property
and erosion of top soils
Hurricanes/Typhoons/Cyclones
A large, swirling, low pressure system
forming over a warm ocean with a
calm “eye” in the center
Called a hurricane in the Atlantic Ocean, a typhoon in
the Pacific Ocean and a cyclone in the Indian Ocean
What other disasters can this cause?
Often bring storm surge (flooding), tornadoes
and heavy rain onto land causing erosion.
The more people move towards the coasts
the greater in damage costs
Earthquakes
Earthquakes occur when the plates, making
up the crust of the Earth, move causing
energy to be released in the form of a
wave
The movement is along the boundary of the
plates called a fault and the waves are
called seismic waves
Seismic waves are measured by the Richter
Scale on a machine called a seismograph
Tsunamis
After an earthquake occurs on the ocean
floor, the shift can cause a huge wave to form
and rush towards land
Most tsunamis are less than 1 meter deep on
formation however as the distance from the
seafloor to the surface of the water decreases
as the wave moves towards land, the height of
the tsunami increases (can be as high as 30m
above sea level) racing towards land at
speeds averaging 700 meters per hour.
Not all ocean floor earthquakes form a
tsunami, however, a tsunami cannot form
without the earthquake occurring
Volcano
Magma from deep within the Earth rises
to the surface of a cone shaped mountain
scorching everything in its path
Volcanoes form where there is movement
of the plates of the Earth’s crust (both at
convergent and divergent boundaries)
Volcanic Eruptions






How can a Volcanic Eruption cause
problems away from the immediate area?
Volcanic dust and ash are thrown into the
air blocking sunlight for long periods.
How would this affect climate?
Colder temperatures and fewer plants
Higher amounts of sulfur producing ACID
RAIN.
Potential for flooding, mudslides erosion.
Ring Of Fire
 Area along the Pacific Plate boundaries
where volcanic eruptions and
earthquakes occur.
9. Mass movements
Large areas of land changes location over a
period of time
(change can be gradual or can occur
quickly)
What are different types of mass
movement?
Avalanche
Landslides
Mudflows
Usually occurs with another event such as:
floods, earthquakes, volcanic
eruptions or after wildfires
Summary Questions
 Scientists hypothesize that a large meteorite
struck the Earth and killed all the dinosaurs,
even those on the other side of the Earth.
Describe how this event could have caused
their extinction.
 How do we plan ahead in order to survive
catastrophic events?
Yet more Summary Questions
 Explain possible impacts of a volcanic
eruption on the Earth’s surface.
 If cities along coasts and major inland
waterways experienced a population
growth, what affects would this growth
cause if floods and hurricanes occur.