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Tectonic PlatesTectonic is Greek for "to put together or take apart." Tectonic plates are found under the oceans and continents. There are twenty plates, but the seven major tectonic plates are, largest to smallest: Pacific, Eurasian, African, American (North), Antarctic, American (South), and Indo-Australian.When the athenosphere, the layer beneath the crust, a.k.a., the slush,, moves, the plates move. This is similar to the collision of two football teams, where almost anything can happen, almost. When you break open a Milky Way Bar, note the moving together and pulling apart which is demonstrated. A few typical results are: volcanoes, earthquakes, fold mountains, fault block mountains, rift valleys, and ocean trenches. Movement of the athenosphere is caused by heat and pressure, and while that affects the crust, sometimes the results don't become visible for many years, but eventually there will be a definite change. In the Milky Way Bar demonstration, the crust is represented by the brittle, hard outer chocolate layer, and the athenosphere by the inner nougat and caramel layers. The pulling apart and putting together of the bar show the effects on the crust by the inner layer, the athenosphere. |
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