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PlateTectonics By: Ellie Ferguson
Plates A plate is a piece, or segment, of crust that moves around on top of the earth. Each plate has boundaries. A boundary is the ending of a plate, or where two plates meet. We live on the North American Plate, which is bordered by the Juan de Fuca plate, the Caribbean plate, the Cocos plate, the African plate, and the Eurasian plate. Millions of years ago, in the carboniferous period all the continents were connected, when they were connected it was called pangea, meaning all lands, in the pangea the segments of crust fit together like a puzzle.Alfred Wegenerhad a theory about pangea, he thought that the continents were connected until they began to drift apart, and that as they hit other plates they formed the earth. His idea wasn’t excepted. Pictures from www.yourtravelbuddynetwork.com/images/usmap.jpg, www.nasm.si.edu./exhibitions/gal113/earthtoday/images/large/plates.jpg, info from www.ucmp.berkley.edu/geology/techist/html, scign.jpl.nasa.gov/learn/plate2/htm, www.freewebs.com/morganisrupert/pangea, www.ux1.eiu.edu.
Convergent Boundaries • There are several types of boundaries. • One type is a Convergent Boundary. A convergent boundary, also known as a subduction boundary, is when two plates going in different directions meet and one slides under the other. • Convergent boundaries are known to make earthquakes and in some special occasions, mountains. An example of a convergent boundary is the Himalayas, which was made with the Indo-Australian and Eurasian plates. info from http://scign.jpl. Nasa.gov/learn/plate2/htm. and http://www.ucmp.berkley.edu/geology/techist/html
Divergent Boundaries A Divergent Boundaryis a boundary which is almost always in the ocean, and it’s where the plate next to a plate pulls away from another and causes ‘sea floor spreading’ as they pull apart new magma comes up through the cracks and as it cools it makes new sea floor. A divergent Boundary can cause earthquakes in the water. One example of a divergent boundary is the Mid-Atlantic range, which involves the North American and European plates. pics from www.geo.utep.edu/kidd/vol_eq_plates.gif and www.dianevarner.com/images/ info from http:// scign.jpl.nasa.gov/learn/plate2.htm
Transform Boundaries Transform Boundaries can cause earthquakes A transform boundary is the only type of boundary that doesn’t create or destroy something. A Transform Boundary is when plates slide past each other. Transform Boundaries often cause earthquakes because as they slide past each other they accumulate and then release energy. One famous transform boundary is the San Andreas fault in California, which is the North American and Pacific plate.
Effects Plate Tectonics can have lots of effects on the earth. One effect is volcanoes. A volcano is a vent, or crater, in the middle that spews lava. Another effect is an earthquake, an Earthquake is a shaking of a plate caused by different types of boundries. A mountain is a result of plate tectonics also, a mountain is caused by the collision of plates, pushing them upwards to create a large land mass. pictures from agoraevengelism.org/images/mayan_volcano.jpg, mdwgraphics.com/images/mtscenic7.jpg, wikimedia.org/wikipedia/commons/2/25/haiti_earthquake_damage.jpg
pics from: wikimedia.org/wikipedia/commons/1/16/hurricane_gaston_landslide_damage.jpg.,media.nowpublic.net/images/49/6/469afb3502fef9cb1ef84a33589f7941.jpg,fountainsofthegreatdeep.com/subduc3.jpg Effects! Mudslide A large glob of mud that moves downward and is very destructive. Landslide A landslide is a collapse of land, usually on a mountain or cliff. Trench A trench is a ditch with really steep sides on an ocean or sea floor.
The USA and Plate Tectonics The USA is not in too much serious danger of effects of plate tectonics, however there are many smaller things that could happen. Some of these are that: • The San Andreas fault could cause a major earthquake, as well as earthquakes from other areas. Also as the plates move they could potentially create volcanoes. The USA could have some problems in the very distant future, such as earthquakes at major fault lines, more volcanoes, especially near the coasts, and there could be some subduction zones that could effect us.