Plate Tectonic Theory & Evidence
By: Parsa & Prashant

During the 1900's, scientists believed that the Earth had cooled down after the Big Bang to resemble a wrinkled raisin.This theory implied that the ranges of the Himalayas had been forced up. However, German geophysicist, Alfred Wegener wasn't satisfied with this result. He researched some more on this topic and during the process, he realized that the seven continents that we know o f today were all clustered together. This cluster of continents was called "Pangaea". He gathered fossils from the coast of Africa and South Africa, and they happened to match. He soon realized that the Appalachian Mountains in North America continued a s t he Caledonian Mountains in Northern Europe. He brought the other continents into his research, and concluded with the fact that 250 million yea rs ago the earth only had one big continent called Pangaea. People still wonder today what had caused the continents to separate.



Explanationcoastline.gif of the Plate Tectonic Theory:
Evidence of Plate Tectonics
The continents and oceans are still changing now. The Himalayas are getting taller. The Atlantic Ocean is getting bigger but the Pacific Ocean is getting smaller.


Diverge
nt Boundaries

The North American Plate is moving away from the Eurasian and the African Plates in the Atlantic Ocean. This is a divergent boundary called the Mid-Atlantic Ridge.


Convergent Boundary

The Andes mountain range of South America contains many volcanoes. They were formed at the convergent boundary of the Nazca and the South American Plates.



Fossil.gifCollision between plates
The Himalaya in Asia is forming where the Indo- Australian Plate collides with the Eurasian plate.

Transforming Boundaries
The Pacific Plate is sliding past the North American Plate, forming the famous San Andreas Fault in California.
Hawaii is moving a rate of about 8.3 cm per year toward Japan.
Maryland is moving at a rate of 1.7cm per year away from England .



plateboundaries.jpg



Bibliography:
http://csep10.phys.utk.edu/astr161/lect/earth/evidence.html
http://www.geologyrocks.co.uk/tutorials/plate_tectonics_evidence
http://hyperphysics.phy-astr.gsu.edu/Hbase/geophys/platevid.html