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Unit 1 Chapter 5
MMS Science 8-Plate Tectonics
| Question | Answer |
|---|---|
| One of the six or seven great divisions of land on the globe. | Continent |
| Wegener's hypothesis that all continents were once connected in a single large landmass that broke apart about 200 million years ago and drifted slowly to their current positions. | Continental Drift |
| A large, ancient landmass that was composed of all the continents joined together. | Pangaea |
| The portion of Earth's crust that lies beneath ocean waters. | Seafloor |
| Hess's theory that new seafloor is formed when magma is forced upward toward the surface at a mid-ocean ridge. | Seafloor Spreading |
| To come together. | Converge |
| To move apart. | Diverge |
| To convert or change. | Transform |
| A theory that Earth's crust and upper mantle are broken into plates that float and move around on a plastic-like layer of the mantle. | Plate Tectonics |
| A large section of Earth's oceanic or continental crust and rigid upper mantle that moves around on the asthenosphere. | Plate |
| A rigid layer of Earth about 100 km thick, made of the crust and a part of the upper mantle. | Lithosphere |
| A plastic-like layer of Earth on which the lithospheric plates float and move around. | Asthenosphere |
| The current in Earth's mantle that transfers heat in Earth's interior and is the driving force for plate tectonics. | Convection Current |