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Alfred Wegener's theory that the Earth's crust is divided into sections that move; he called the sections plates.
Greek word meaning "all Earth" or "all land"; a large supercontinent that Alfred Wegener said existed hundreds of millions of years ago.
The first set of waves that travels quickly through the interior of the Earth after an earthquake
The scale that Charles Richter developed to measure and gauge an earthquake's strength
The third set of waves that moves in a circular pattern through the Earth's surface after an earthquake.
The second set of waves that travels more slowly through the Earth after an earthquake, cutting through the rock in the Earth's surface as they move.
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