The Earth's Layer

3. A wave that rolls along the ground just like a wave rolls across a lake or an ocean.
6. Paleontologist noticed that these were the same on different continents even though the continents were separated by oceans.
7. Period 250 million years ago.
8. A point in the Earth's surface directly above the focus.
11. Mechanical vibrations that occur inside the Earth which is caused by the breakage of rocks.
12. Continental crust is made of this dense rocks.
13. The outermost and thinnest layer of the Earth.
14. Other possible process involved in the tectonic plate movement.
16. A wave that causes most damage to structures during an earthquake.
18. The middle of layer of the Earth.

1. If subduction is faster than Seafloor Spreading, the ocean _______.
2. One of the evidences that supports the Seafloor Spreading.
3. Process where the older seafloor sinks, the weight of the uplifted ridge pushes the oceanic crust toward the trench at the subduction zone.
4. An element that makes up 5% in the Earth's crust.
5. It is subdivided into two layers: the inner and the outer core.
7. A wave/pulse energy that travels quickly through the Earth and through liquids.
9. Current in the mantle because of the heat from the inner layers of the Earth, and is the force that drives the plates.
10. The ridge is offset by ________.
15. A Danish seismologist. He discovered a new region of seismic reflection within the core.
17. Rigid sections of the lithosphere that move as a unit.