TECTONIC PLATES

There are 3 types of plates. There are convergent, divergent and transform fault.

Convergent is when 2 plates crash together and form a mountain or volcano. There are 3 types of convergent. One is when a continental plate collides with an oceanic plate. The oceanic goes under, because it's more dense. The second type is when 2 continental plates collide. One is denser, so it's goes under the other. The last type of convergent is when 2 oceanic plates collide. The denser one goes under the other.

Divergent plates are when 2 plates move away from each other. The magma flows up and it hardens, creating new land. They create trenches.

Transform fault is when 2 plates rub against each other and create friction. This causes earthquakes.

The theory of plate tectonics is that the crust is always moving. It also says that the crust is divided into plates.There are 18 plates. There is 8 major and 10 minor. The plates only move 1-4 centimeters a year.

ALFRED Wegener

Alfred Lothar Wegener helped the theory Pangea come along very far. He was born on November 1st, 1880 and died on November 2nd,1930. He was not the first to suggest that the continents had once been connected, but he was the first to present extensive evidence from several fields.
He wrote a book on it, called The Origin of Continents and Oceans.

HENRY HESS

Henry Hess was born on May 24, 1906 in New York. In 1960 he hypothesised the theory of sea-floor spreading. After about 52 years, he agreed with Alfred Wegener. Henry died on August 25, 1969.

When scientists found fossils, they were on different continents. They connected the continents and that was evidence that the plates move, and that Wegener's idea, was somewhat true.

The problem with Wegeners Idea, was that he knew that the plates moved, but he didn't know why or how.

The layers of the Earth are the Crust, Mantle, Outer Core and the Inner Core. The crust is where the tectonic plates are. The mantle is what make the crust move, since it is made out of molten and hard rocks.

Percent of ABOUT how much each layer is.

FUN FACTS

• The name Pangea come from the Greek language, pangaia, meaning "all the Earth"
• Tectonic plates move about as fast as a person's fingernails grow-about 2 to 4 inches (5 to 10 cm) per year.
• Pangea wasn't the only super continent. There were many before it.

The minor plates are the Arabian Plate, the Caribbean Plate, the Cocos Plate, the Indian Plate, the Juan de Fuca Plate, the Philippine Sea Plate, the Scotia Plate and sometimes the Nazca Plate.

The major plates are the African Plate, the Antarctic Plate, the Eurasian Plate, the Indo-Australian Plate, South American Plate, the Pacific Plate, the North American Plate, and the Nazca Plate sometimes considered a major plate instead of a minor plate.

BIBLIOGRAPHY

• http://www.wisegeek.org/how-many-tectonic-plates-are-there.htm
• http://www.ucmp.berkeley.edu/history/wegener.html
• http://www.amnh.org/education/resources/rfl/web/essaybooks/earth/p_hess.htm...
• http://utahscience.oremjr.alpine.k12.ut.us/sciber00/7th/earth/sciber/erlaye...