Download Tsunamis - Laconia School District

Tsunamis
By: Courtney Stryke ♥
12/20/06 Blue
What is a tsunami:
A Tsunami is a series of huge waves that
happen after an undersea disturbance, such as an
earthquake or volcano eruption. The waves travel in
all directions from the area of disturbance, much like
the ripples that happen after throwing a rock. The
waves may travel in the open sea as fast as 450 miles
per hour. As the big waves approach shallow waters
along the coast they grow to a great height and
smash into the shore. They can be as high as 100
feet. They can cause a lot of destruction on the
shore. They are sometimes mistakenly called "tidal
waves," but tsunamis have nothing to do with the
tides.
What Causes Tsunamis:
Most tsunamis are
caused by earthquakes
generated in a subduction
zone, an area where an
oceanic plate is being
forced down into the mantle
by plate tectonic forces. The
friction between the
subducting plate and the
overriding plate is
enormous. This friction
prevents a slow and steady
rate of subduction and
instead the two plates
become stuck.
Where do Tsunamis occur:
Generally the danger of a
tsunami occurring exists where earthand lake-quakes are possible, in areas
where tectonic plates collide with each
other, drift past each other or collide,
as well as in other areas with
geological faults. They also occur in
the Pacific ocean as it is located on a
plate mostly made of water. The
Pacific ocean is also surrounded by the
Ring of Fire, a highly active volcano
and earthquake zone.
A Diagram of a Tsunami:
•
This is how a
tsunami starts. When
movement along a fault
moves the seafloor
upward, water is also
pushed upward and
becomes tsunami waves.
Historical Event About
Tsunamis:
On the morning of December 26, 2004 a
magnitude 9.3 earthquake struck off the Northwest
coast of the Indonesian island of Sumatra. The
earthquake resulted from complex slip on the fault
where the oceanic portion of the Indian Plate slides
under Sumatra, part of the Eurasian Plate. The
earthquake deformed the ocean floor, pushing the
overlying water up into a tsunami wave. The tsunami
wave devastated nearby areas where the wave may
have been as high as 25 meters (80 feet) tall and
killed nearly 300,000 people from nations in the
region and tourists from around the world. The
tsunami wave itself also traveled the globe, and was
measured in the Pacific and many other places by
tide gauges. Measurements in California exceeded
40 cm in height, while New Jersey saw water level
fluctuations as great as 34 cm.
Ten Facts about Sumatra:
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The tsunami was in the Indonesian island of Sumatra.
It was a undersea earthquake that started this tsunami.
The earthquake that caused the tsunami was a magnitude 9.3
earthquake.
The earthquake resulted from a complex slip.
The earthquake triggered a series of devastating tsunamis.
The earthquake deformed the ocean floor, pushing the overlying
water up into a tsunami wave.
The waves reached to 25 inches high (80 feet)
This tsunami killed nearly 300,000 people from nations in the
region and tourists form around the world.
The tsunami itself traveled the globe.
Eighteen countries around the Indian Ocean sustained damage
from the tsunami.
Sumatra Video:
Safety Measures:
Before
If there is noticeable
recession in water away from
the shoreline this is nature's
tsunami warning and it should
be watched. You should move
away immediately.
•
During
•
•
Turn on your radio to learn if
there is a tsunami warning if
an earthquake occurs and you
are in a coastal area.
Move inland to higher ground
immediately and stay there.
After
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•
Stay away from flooded and
damaged areas until officials
say it is safe to return.
Stay away from debris in the
water; it may pose a safety
hazard to boats and people.
Pictures of Tsunamis:
The End!