Plate Tectonics

2. the process by which the ocean floor sinks beneath a deep-ocean trench and back into the mantle.
4. device that bounces sound waves off underwater objects and then records the echo's of these sound waves
7. a force that acts on rock to change its shape or volume
9. place where two plates slide past eachother.
10. a tall, cone-shaped mountain in which layers of lava alternate with layers of ash and other volcanic materials
11. squeezing rocks till they fold or break
12. plates where two boundaries come together or collide.
14. when the edge of a contiental plate collides with an oceanic plate
18. pushing a massive rock in two different directions

1. bends in the rock to form when compression shortens and thickens the Earth's crust.
2. a wide, gently sloping mountain made of layers of lava and formed by quiet eruptions.
3. large waves produced by earthquakes in the ocean floor.
5. plates where two plates move apart.
6. rise in the asthenosphere and spread out beneath the lithosphere.
8. stretching rock so that it becomes thinner in the middle
13. weak spot in the crust where molten material comes to the surface
15. fold in a rock that bends upward.
16. the motion or trembling of the ground produced by sudden displacement of rock in the Earth's crust.
17. when magma reaches the surface.