Transcript Earthquakes, Volcanoes, and Mountain building

Earthquakes and Mountain
Building
Presented by Mrs.Tonya
Layers of the Earth
Crust
Mantle
Inner Core
Outer Core
Crust
• 20 miles thick below
continents
• 6.5 miles thick below
oceans
• Thin outer layer that
surrounds the mantle
• Rocky and brittle
• Less than 1% of
earth’s volume
Mantle
• 1,800 miles thick
• Mostly solid but can
slowly deform(plastic)
• 84% of earth’s
volume
• 1000oC
Core
Inner Core
• 758 miles in radius
• Solid
• 4300oC
Outer Core
• 1,400 miles thick
• Liquid layer
• 3700oC
Math Trivia
• The crust is 1% of the earth’s volume and
the mantle is 84% of the earth’s volume.
What percentage of the earth’s volume is
the core?
Answer: 15%
Egg Model
Tectonic Plates
• Pieces of the crust and uppermost mantle that
make up the lithosphere
• Interconnecting pieces that fit together like a
puzzle
Is it possible that all of the
continents were connected to
form one landmass?
Tectonic plate activity
Theory
• Similar species
(fossils)
• Matching layers of
rock
• Coastlines appearing
to fit together
Movement of tectonic plates
• Caused by convection currents(theory)
• 3 types of movement
Normal fault
• Tectonic plates are moving apart
• Lithosphere is stretching
Reverse fault
• Tectonic plates are moving towards one
another
Strike Slip fault
• Tectonic plates slide past one another
What causes mountains to be
formed?
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2 tectonic plates collide
Slabs pile into one another
Causes crust to deform and elevate
Oreo demo
What causes a volcano?
• 2 tectonic plates collide
• 1 plate boundary is
subducted or forced
deeper into earth
• Causes other slab to
fold deeply
• Hot magma can seep to
surface of earth
• Spreading of two plates
can cause hot magma
to rise to surface
What causes an earthquake?
• The release of stored up energy as the
plates move past each other
• The energy moves outward from the fault
in all directions in the form of waves
• When the waves reach the earth’s surface
this causes the ground to shake
Primary waves
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Compression waves
Push and pull
Slinky demo
The fastest seismic wave
Secondary waves
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Shear waves
Side to side motion
Slinky demo
Slower than primary wave
Love waves
• Surface waves
• Cause the most damage to buildings
• Travel the slowest of all seismic waves
How far is the earthquake?
• Detect p-waves and s-waves on a
seismograph
• Calculate difference between waves
• Calculate distance to earthquake
• Distance = rate X time
• Example
You are traveling 30 miles/hour and you
travel for 2 hours. What distance have
you traveled?
Distance = (30 miles/hour)x(2 hours)
= 60 miles
3 locations to determine where
earthquake is located
Math Trivia
• The Himalayan Mountains formed when
the Indian Plate crashed into the Eurasian
Plate. Today the two plates are still
colliding and the Himalayas continue to
rise. If the first person climbed Everest in
1953 and the mountains grow about .5
inches per year. How many more inches
would you have to climb if you climbed
Everest in 2009?
Answer: 28 inches