Monday, November 8, 2010

Continental Jigsaw Puzzles! Buy yours now!

Earthquakes and volcanoes show the edges of the plates. Earthquakes and volcanoes are distributed at the edges of the tectonic plates, because the crust is thinnest there. When the crust is thin, the mantle inside the earth has an easier time of getting up. Also, at the edges of plates, when the plates collide or slip underneath each other, the friction causes earthquakes.
Here is a website, where there is a picture of earthquake predictions at the bottom!

Fossil distribution also shows evidence of plate tectonics. Archaeologists have found fossils on the west coast of Africa of the same species as fossils on the east coast of North America. These fossils are mostly of land-locked animals that would not have been able to cross oceans. Clearly, these continents were once the same continent, but broke apart.
Here is a picture of fossil distribution across S.America, Africa, Antarctica, Australia, and India...

Closer to the ridges, the sea floor is newer. Because of the recycling of the oceanic crust, the sea floors closer to the ridges are newer, while the sea floors closer to the trenches are older.
Here is a picture of the ages of the sea floors...

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