I dedicate this to Alfred Wagner and all the people who research about this.

I learned that convenction currents move the earth.

A convection current is a hot and cold current.

As the currents are hot they go up but as they are there for along time they start to cool off and come back down.

The Plate Tectonic Theory is about everytime currents move plate tectonic move against each other and start to shift and move the country, states, cities, and even the whole world.

Earths layers

Alfred Wagner proposed the theory of Continental Drift. He said that the earth was once together

• South America and Africa were once together because they line up pretty good.
• If you combine South America and Africa their mountain range combine .
• They found fossils of a Mesosaurus were fresh water reptiles that could not have survived swimming across the Atlantic Ocean but were found there.
• They found rocks deposits in areas that cannot be formed where the continents are now

Nobody believed Alfred Wagner cause he couldn't say why it happen and how.

Continental Drift

Sea Floor Spreading

Harry Hess proposed the sea floor spreading theory. The sea floor spreading is the process that continually adds new material to the ocean floor

• New material is erupting along the mid-ocean ridge
• Magnetic stripes- rock that make up the ocean floor lie in a pattern of magnetized stripes
• Drilling smapples- scientists were able to determine the age of rocks

After the disocvery of Alfred Wagner they put both theories together

Plate tectonics

Explains the formation, movement, and subduction of earths plate

• There are 12 large irregular and un shaped plate tectonics
• There are 7 big plate tectonics that is 94% of earths surface

Types of stress

Convergent- Compression:

continent/continent=mountains

ocean/ocean=trench

ocean/cont=trench+volcanoes

Divergent- Tension:

ocean/ocean=rift valley

continent/continent=volcanic island

Transform- Shear

fault

earthquake

Convergent boundary

The plates go towards each other: Compression

They create:

• continent/conttinent=mountains
• ocean/ocean=trench
• ocean/continent=trench+volcanoes