Continental Drift and Plate Tectonics

3. (sound navigation and ranging) is a technology that uses sound waves to detect and navigate in water.
4. is a force that drives plate tectonics, specifically at mid-ocean ridges.
6. the pulling force exerted by a cold, dense oceanic plate plunging into the mantle due to its own weight.
7. is the theory that the Earth's surface is made of tectonic plates that move over the mantle.
11. the slow, circular movement of material within Earth's mantle, driven by heat from the core and radioactive decay.
12. is a tectonic plate boundary where two tectonic plates slide past each other horizontally.
13. a change in the Earth's magnetic field where the magnetic north and south poles switch places.

1. are huge pieces of Earth's crust and upper mantle that move slowly over time.
2. are localized zones of intense heat in Earth's mantle, beneath the crust, that cause volcanic activity.
4. a deep, elongated depression in the Earth's crust that forms when tectonic plates pull apart.
5. proposed the theory of seafloor spreading
8. a supercontinent that existed during the late Paleozoic and early Mesozoic eras, approximately 300 to 200 million years ago
9. the theory that Earth's continents move over time.
10. proposed the Continental Drift theory
14. the downward movement of the edge of a plate of the earth's crust into the mantle beneath another plate.