Plate Tectonics

By: Anthony Perkins

The Pangaea TheoryPangaea was a supposed supercontinent made up of all our current continents.Alfred Wegener - In 1912 he came up with the theoryOf Pangaea. The name means “all lands.” -He said Pangaea was probably intact Until late Carboniferous period.

http://www.ucmp.berkeley.edu/geology/techist.html

- other than geology he was accomplished in Astronomy, Meteorology and Climatology. These all helped him to come up with his theory/discovery.When Wegener first proposed the idea it was dismissed. - He could not provide an adequate explanation of the forces responsible for continental drift or disprove the theory that Earth was solid and immovable.

http://www.ucmp.berkeley.edu/geology/techist.html

Arthur Holmes - His ideas later assisted in the recognition

of Wegener’s theory. - He elaborated on Wegener’s hypothesis.

He said that thermal convection affects the mantle. It causes it to heat and cool. Heating and cooling over a period of time can cause a continent to split up and move.

- This received little attention at the time it was proposed.

http://www.ucmp.berkeley.edu/geology/techist.html

The theory being discussed at this time was the Contraction theory.

- This said that the Earth was once a molten ball and the act of cooling caused some parts of the Earth to fold in on itself.

http://www.ucmp.berkeley.edu/geology/techist.html

Convergent BoundariesConvergent Boundary: A boundary

were one plate overrides another one and forces it under. The one pushed under becomes part of the mantle again. Convergent Boundary

http://scign.jpl.nasa.gov/learn/plate4.htm

Plate: A piece of the broken up lithosphere that floats on the asthenosphere. (top part of Earth.)

Boundary: Where two plates meet.

What it causes: Mariana Trench Mountains Earthquakes VolcanoesTrenches

Mountain

Mountain: A raised spot on the Earth that comes to a Point.( a big hill.)

Earthquake: A big shaking of the Earth from the motion of The plates moving.

Trench: A dip in the ground formed by the two plates that meet.

Volcano: An opening in the ground that magma come out of the Earth.

One example of a Convergent Boundary is the Ring of Fire.

- A ring of volcanoes around the edges of the Pacific Plate.

- due precisely to there being a lot of convergent zones around there. Volcano

http://scign.jpl.nasa.gov/learn/plate4.htm

Divergent BoundariesDivergent Boundary: At a Divergent

Boundary two plates move away from each other. As the plates move away from each other mid- ocean ridges are formed because magma forces itself up through the cracks and cools. Mid-Ocean ridge

What it causes: - Mid-Ocean Ridgeshttp://scign.jpl.nasa.gov/learn/plate4.htm

One example of a Divergent Boundary is the Mid-Atlantic range.

- This helps to move North America and Europe farther apart.

- The two plates involved in this are the North American plate and the Mid-Atlantic Ridge

Eurasian plate.

http://scign.jpl.nasa.gov/learn/plate4.htm

Transform BoundariesTransform Boundary: A boundary were

two plates slide past each other. Material is neither created nor destroyed. The plates just move past each other. Transform Boundary

http://scign.jpl.nasa.gov/learn/plate2.htm

What it causes: - Earthquakes - Mudslides - Landslides

Mudslide

Landslide

Earthquake

Mudslide: The rapid downward movement of earth caused by shaking

Landslide: the falling or sliding of rock, soil, moss etc.

http://scign.jpl.nasa.gov/learn/plate2.htm

One example of a Transform Boundary is the San Andreas Fault.

- Fault that is in California. - The North American and Pacific plates are

moving past each other and it is the site of many earthquakes.

http://scign.jpl.nasa.gov/learn/plate2.htm

San Andreas Fault

Real World ConnectionsThe United States - we live on the North American Plate. - Most of the U.S. is on the North American

Plate with the exception of Hawaii and some of California which are on the Pacific Plate.

- the U.S. is bordered by the Pacific Plate and the Juan de Fuca Plate.

http://geology.com/plate-tectonics.shtml

The United States

Ohio is at risk of an Earthquake only if it is a very serious one. We feel them in Ohio but usually they are not very severe.

If the ancient Volcano in Yosemite were to blow again it would be disastrous.

Ohio

http://www.dnr.state.oh.us/OhioGeologicalSurvey/GeologyTopics/GeologicHazards/tabid/7902/Default.aspx

In the very distant future California may break away from the United states. This is because of the San Andreas Fault. The Pacific Plate and the North American Plate could work it off just like Pangaea got worked apart.

https://geohazards.usgs.gov/

California