PLATE TECTINIC

3. Earth's thickest layer, lying just below the crust and making up 70 percent of Earth's volume.
5. Earth’s outermost layer formed by lighter materials, such as silicon and oxygen, floating to the top during Earth’s early cooling period.
6. A steep-sided valley formed on land when magma rises to Earth's surface at a spreading centre.
8. a partly molten layer in Earth's upper mantle just below the lithosphere.
11. Tectonic plates that are colliding.
14. The region where magma breaks through Earth’s surface, continually forcing apart old rock and forming new sea floor.
15. A number that rates the strength (energy) of an earthquake.

1. An area of subduction, which typically experience large earthquakes and volcanic eruptions.
2. A sudden, ground-shaking release of built-up energy at or under Earth’s surface.
4. A pattern of alternating stripes of different directions of magnetic polarity in rock on the sea floor.
7. Earth’s solid centre.
9. An area where molten rock rises to earth’s surface.
10. The region where two tectonic plates are in contact.
12. The study of earthquakes and seismic waves.
13. In geology, the location inside Earth where an earhquake starts.