Plate Tectonics Myers Social Studies

Layers of the Earth Draw a circle in your notebook Now draw a SLIGHTLY smaller circle inside this one Draw a small circle in the middle And one more smaller circle in the middle

Label your drawing Mantle Crust Outer Core Inner Core

Look at this

Label your drawing Magma Made of Rock Liquid Solid

The Earth’s Surface

Plate Tectonics Watch this video to introduce the concept of Plate Tectonics

Theories of Continental Drift 1912 – Alfred Wegener used fossil evidence to explain continental drift His theory was not accepted until years later

Eventually sonar Technology that was developed to locate German Uboats

was used during the 1960s to map the ocean floor

Finally scientists had a more accurate picture of the earth’s surface The mapping also revealed several faults below the ocean’s surface Confirming the existence of the earth’s plates

What are Plate Tectonics Theories? The outer shell of the earth has several plates The plates move on a layer of liquid rock located miles below the surface The plates move slowly across the earth 200 million years ago – one giant continent existed called Pangea

Pangea

How Many Plates are There? There are around 30 plates –12 of them are considered major tectonic plates

What are the Plates Made of? Partly crust Partly mantle Averages 60 miles thick Could be anywhere from 5 – 120 miles thick

What are Faults? Faults are cracks that exist on the edges of plates. The plates movement against each other can cause serious, sometimes visible cracks in the Earth’s crust

How Fast do Plates Move? The move somewhere between 1 inch and 8 inches in a year One Inch 8 inches

How do These Huge Plates Move? The plates move on a flowing layer of rock in the mantle called the Asthenosphere The Asthenosphere reaches temperatures of 3600 degrees

Where are the Plates Going? In several directions The Atlantic Ocean is growing The Pacific Ocean is shrinking

Where are the Plates Going?

Plate Interaction Divergent Plate Boundaries –Plates spread out or separate Causes volcanic activity Creates New land!

Plate Interaction Divergent Plate Boundaries –Plates spread out or separate Causes volcanic activity Creates New land!

Plate Interaction Divergent Plate Boundaries –Plates spread out or separate Causes volcanic activity Creates New land!

Divergent Video

Plate Interaction Convergent plate boundaries –Also called subduction Causes earthquakes, and volcanic activity Creates mountains –Andes, and the Himalayans

Plate Interaction Convergent plate boundaries –Also called subduction Causes earthquakes, and volcanic activity Creates mountains –Andes, and the Himalayans

Plate Interaction Convergent plate boundaries –Also called subduction Causes earthquakes, and volcanic activity Creates mountains –Andes, and the Himalayans

Convergent

Making Mountains?

Plate Interaction Transform Faults Creates Major Earthquake

Plate Interaction Transform Faults Creates Major Earthquake

Plate Interaction Transform Faults Creates Major Earthquake

Plate Interaction Transform Faults Creates Major Earthquake

Plate Interaction Transform Faults Creates Major Earthquake

Transform

Two Faults Illustrated