Plate Tectonics Adam Toerner Plate: A large piece of land that makes up the Earth and creates landforms. Volcano: A mountain-like landform with an underground vent allowing magma to sprout out of the surface. Earthquake: A tremor of the earth's surface usually triggered by the release of underground stress along a fault. Boundary: Where two plates meet Trench: A depression or excavation in the ground Landslide: A large mass of land that shifts and moves, causing debris of land to fall. Mudslide: A large mass of mud that shifts and moves rapidly, causing mud to fall Mountain: A tall landform that is taller than the surrounding area and is usually in a peak form.

Pangaea Alfred Wegener was a German scientist who studied astronomy, physics, and geology. He was the first person to present the theory of continental drift and Pangaea in 1912 At first, Wegener’s theory wasn’t accepted. In the 1950’s, scientists began to rethink his idea and noticed that a lot of evidence supported it. Pangaea means “all lands” or “entire”. It is a supercontinent. Pangaea is thought to have existed millions of years ago, in the Jurassic ages.

Pangaea 2 Before Alfred Wegener proposed his idea, scientists were discussing that the planet was once a molten ball and in the process of cooling. Then the surface cracked and folded up on itself. The big problem with this idea was that all mountain ranges should be about the same age, and this is known not to be true. This is called “the contraction theory”. Alfred Wegener was a geologist, but he also studied physics, astronomy, and astrology. This probably helped him because he knew how the universe worked and was able to use that knowledge to study how the Earth worked. Those three studies are each helpful with his theory.

Pangaea 3 Arthur Holmes, Harry Hess, and Robert Dietz all elaborated on Alfred Wegener’s theory and all agreed that Earth’s continents and plates move. jpg

Convergent Boundaries Convergent Plate Movement: Two plates collide, resulting in… 1. One plate is forced underneath the other, causing magma to come up. 2. They both force each other upward or downward, resulting in a mountain, volcano, or rift(ditch) nics/description_plate_tectonics.html

Convergent Boundaries 2 Mountains, Trenches, Volcanoes, Earthquakes, and Landslides can be effects of a convergent plate boundary Example: The Juan de Fuca plate and the North American plate on a convergent boundary form the Cascade Mountains.

Divergent Boundaries Divergent Plate Movement: Two plates spread away from each other, which can result in new crust. Earthquakes, Volcanoes, Trenches, Landslides, Mudslides and Mountains can all be effects of a divergent boundary. Example: The Arabian and African plates spread apart at a divergent boundary to form the Red Sea. nics/description_plate_tectonics.html

Transform Boundaries Transform Plate Movement: Two plates quickly slide or rub against each other, usually resulting in an earthquake. Earthquakes, Landslides, Trenches, and Landslides are a common result of a transform boundary. Example: The San Andreas fault is formed from the Pacific plate and the North American plate. nics/description_plate_tectonics.html

Real World Connections We live on the North American Plate, bordered by the Pacific Plate, Caribbean Plate, Cocos Plate, South American Plate, African Plate, and Eurasian Plate. California might have problems in the future because of the San Andreas Fault. Those earthquakes could cause serious damage to the land and cities. Some problems we might face in the very distant future might include tsunamis, the splitting of the mid-Atlantic ridge, sinkholes, or collisions of continents. ml/geo_f03/tabid/8307/default/aspx