Earthquakes and Mountain Building

Earthquakes and Mountain Building

Presented by Mrs.Tonya

Layers of the EarthCrust

Mantle

Outer CoreInner 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?

• 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

• Compression waves

• Push and pull

• Slinky demo

• The fastest seismic wave

Secondary waves

• 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