Transcript Natural Disasters - Causes & Effect 2011

NATURAL DISASTERS
The causes and effects
AND
How equilibrium, and potential and kinetic
energy of an environment are affected
Pictures and links provided by FEMA
Which of the following can
happen in New York State?
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tornadoes
hurricanes
floods or droughts
forest fires
earthquakes
volcanoes
tsunamis
severe thunderstorms or lightning
blizzards or avalanches
The world is always changing.
Natural disasters are changes to the environment that
are so great they may cause changes to the shape of
the land, destruction of property, or affect the lives of
people and other living things.
The Earth is dynamic. Great changes occur deep inside
the Earth and on its surface each day. The changes that
occur on the outer part of the Earth, such as floods or
tornadoes, happen because of different kinds of weather
conditions; specifically, severe changes in the weather.
HURRICANES and
TORNADOES
Hurricanes and tornadoes are fierce storms that
cover large areas with strong winds from 74 - 250+
mph that spin counterclockwise. During these deadly
storms, trees can be uprooted, buildings destroyed,
cars overturned, power lines downed, and lives can
be lost. Hurricanes are extremely dangerous
because of high winds and flooding.
TSUNAMIS
A tsunami is a giant sea wave that crosses the
ocean toward land building in size and strength
as it gains energy. Tsunamis occur as a result of
movement caused by the Earth, either from an
earthquake or a landslide. When the tsunami
reaches the coast, it is highly destructive because
of the huge size of the waves, which can be over
100 feet high, and the severe flooding it causes.
Tsunamis are extremely dangerous and deadly.
Japanese tsunami caused by earthquake (March 2011)
TORNADOES
 Found mainly in the
mid-west plains area of
the U.S. known as
Tornado Alley
HURRICANES
 Hurricanes are found
mostly along coastal
areas where warm
ocean currents travel
westward across the
Atlantic Ocean toward
the East coast.
FLOODS
A flood is caused by an overflow of water which
covers land that is usually either too dry and
rainwater cannot penetrate the ground because it is
too hard or because the ground is already saturated
with water from too much rain so it causes runoff
flood water.
Floods often occur in the Spring due to heavy rain or
is caused by snow melting and the rivers burst their
banks and overflow.
Costal floods are caused by high tides, a rise in sea
level, storm waves or a tsunami.
FLOODS
 Major flooding occurs in low lying areas or where
major rain events can occur
FOREST FIRES (WILD FIRES)
 Wild fires are
common in dry
places with
numerous forests
and little rain
DROUGHT
A drought is the lack of rain for a long time.
In 1968, a severe drought began in Africa.
Children born during that year were five years
old before rain fell again.
FOREST FIRES
(WILD FIRES)
Fires can quickly burn wildly out of control in dry
areas of forest. Fires are caused by lightning, sparks
of electricity or careless people. Strong winds may
blow a forest fire to areas where people live. Once
the area has been destroyed by fire, without the
vegetation to hold the soil in place, the area is
susceptible to massive landslides or mudslides.
EARTHQUAKES
An earthquake is a violent shaking of the
ground. Sometimes it is so strong that the
ground splits apart.
When parts of the Earth, called tectonic plates,
interact with each other giant shock waves
move upwards towards the surface causing the
earthquake.
The area on the surface of the Earth where the
most damage occurs is called the epicenter.
DUCK, COVER, HOLD!
EARTHQUAKES
 Earthquakes
are mainly
found along
fault line
boundaries
such as the
west coast
where North
America once
separated from
the super
landmass
called Pangea
SAN ANDREAS FAULT
California
VOLCANOES
A volcanic eruption is the spurting out of
gases and hot lava from the asthenosphere
through an opening in the Earth’s crust.
Pressure from deep inside the Earth forces
ash, gas and molten rock to the surface.
Some volcanic eruptions are explosive
such as Mount St. Helens.
VOLCANOES
 Active volcanoes in the
U.S. are found mainly in
the area of the Ring of
Fire, which includes the
states of Hawaii, Alaska,
Oregon, California, and
Washington. The
greatest chance of
eruptions occur near
areas where many
people live such as
Hawaii and Alaska.
SEVERE THUNDERSTORMS
AND LIGHTNING
 Thunderstorms are most likely to occur in the spring and
summer months and during the afternoon and evening hours,
but they can occur year-round and at all hours of the day or
night. Along the Gulf Coast and across the southeastern and
western U.S., most thunderstorms occur during the afternoon.
Thunderstorms often occur in the late afternoon and at night in
the central U.S. Florida has the most lightning strikes.
BLIZZARDS
Blizzards can happen in NYS because of
weather conditions known as lake effect snow.
When cold arctic air meets the warmer waters in
the large lakes in central NYS, conditions are
ideal for the formation of lake effect snow. If the
snow fall continues for long periods of time and is
accompanied by severe winds, a blizzard may
develop. Blizzards can be deadly because the
strong winds can cause hazardous road
conditions such as “white-outs” or “black ice”,
and knock down trees and power lines, causing
homes to be without heat and power for days.
AVALANCHES
An avalanche is a rapid movement of snow, ice
and rock down a mountainside. Avalanches
happen very suddenly and can move as fast as
a racing car up to 124mph.
Avalanches can be caused by –
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snow melting quickly
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snow freezing, melting then freezing again
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someone skiing
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a loud noise or an Earth tremor
LANDSLIDES
The Tully Valley landslide that occurred on
April 27, 1993, just south of Syracuse, New York,
is considered one of the worst natural disasters in
U.S. history. This natural disaster fortunately did
not cause any loss of life, but caused much
destruction to property and loss of many homes
in the area.
The massive rock slide down the mountainside
lasted less than an hour, covered roadways with
mud 15 feet deep, and people had to be rescued
by helicopter from the rooftops of their homes.
Tully Valley landslide (April 27, 1993)
HOW THE ENVIRONMENT AND
LIVES ARE AFFECTED BY
NATURAL DISASTERS
 Natural Disasters are events that occur
naturally on the Earth. They affect the
characteristics of the environment and living
things, and have ultimately influenced the
history of the world.
 During a natural disaster, potential energy
becomes kinetic energy and alters the
equilibrium in the environment.
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