Plate Tectonics By: Sam Shockley

Pangaea The theory of Pangaea was created by Alfred Wegener in At 1 st scientists didn’t believe him because he didn’t have an explanation for it. Pangaea means “All Lands”. Pangaea was in form about 300 million years ago html

Pangaea 2 When Wegener introduced his theory, the “Contraction Theory” also was around. It stated that the Earth was once a molten ball, and the cooling of the surface cracked and folded up on itself. Alfred Wegener was also a Meteorologist and a Astronomer. Those help him with Geology because Astronomy has to do with gravity and gravity had to do with the continents moving. Meteorology gave him a better understanding of the Earth. echist.html

Pangaea 3 Harry Hess and R. Dietz later supported Wegener's theory. They proved that convection is at work under Earths surface. echist.html

Convergent Boundaries A Convergent Boundary is when 2 plates are coming together and the more dense plate goes under the less dense plate. Convergent Boundaries can cause Earthquakes(Series of vibrations induced in Earths crust), Volcanoes(A vent in Earths crust through which lava, steam, and ashes come out), Mountains, Trenches, and Mud/Land slides( The downward falling of the Earth). s.gov/Glossary/PlateTectonics/description_ plate_tectonics.htmlv/learn/plate2.htm

Convergent Boundary 2 An example of a Convergent Boundary is the Washington-Oregon coastline. That is where the Juan de Fuca oceanic plate is. A plate is a constantly moving piece of Earths crust. s.gov/Glossary/PlateTectonics/description_ plate_tectonics.htmlv/learn/plate2.htm

Divergent Boundaries A Divergent Boundary is when 2 plates move away from each other. Divergent Boundaries cause Earthquakes, Mountains (natural elevation of the Earths surface), Trenches(A long narrow excavation in the ground), Volcanoes, and ridges. An Example of a Divergent Boundary is the Mid- Atlantic Ridge. That is on the North American and the Eurasian plate. s.gov/Glossary/PlateTectonics/description_ plate_tectonics.htmlv/learn/plate2.htm

Transform Boundaries A Transform Boundary is when 2 plates build up pressure then slide past each other with a lot of force. A boundary is when 2 things come together. Transform Boundaries can cause Earthquakes, Faults, and Fracture Zones. An example of a Transform Boundary is the San Andreas Fault. It is on the North American and the Pacific Plate. s.gov/Glossary/PlateTectonics/description_ plate_tectonics.htmlv/learn/plate2.htm

Real World Connections We live on the North American Plate. The plates that border the USA is the Nazca, South American Pacific, African, and the Eurasian plate. Most of the USA isn’t in danger but California is because of the San Andreas Fault. Faults cause Earthquakes and the San Andreas is one of the biggest in the world. l/geo_f03/tabid/8307/Default.aspx

Real World Connections 2 The USA in the future will move away from Europe and South America. l/geo_f03/tabid/8307/Default.aspx