U2 Earth, Earthquakes and Volcanoes

1. The process where a denser oceanic plate is forced under a less dense continental plate and melts in the mantle.
5. A chain of volcanoes formed above a subduction zone where magma rises to the surface.
6. The point on Earth's surface directly above an earthquake’s focus where the shaking is strongest.
9. The hot, liquid layer surrounding the inner core made of iron, nickel, sulphur, and oxygen.
11. A boundary where two plates slide past each other horizontally, causing earthquakes but no new crust formation.
12. A lowland region formed where continental plates diverge and the crust thins.
14. Circular movements of molten rock in the mantle caused by heat from radioactive decay, driving plate movements.
15. The thickest layer of the Earth made of semi-molten solid and liquid rock beneath the crust.
18. The thin, solid outermost layer of the Earth where we live, consisting of continental and oceanic types.
19. The semi-molten layer of the mantle beneath the lithosphere that allows plates to move.
20. The location beneath the Earth's surface where the earthquake originates.

2. A boundary where two tectonic plates move away from each other, creating new crust.
3. An underwater mountain range formed at a divergent plate boundary where new ocean crust is created.
4. The rigid outer layer of the Earth, including the crust and upper mantle, broken into tectonic plates.
7. A boundary where two tectonic plates move toward each other, often causing subduction or mountain formation.
8. The energy waves produced by earthquakes that travel through the Earth.
10. A type of fault where two plates slide past one another, often causing earthquakes.
13. The hottest, solid center of the Earth composed mainly of iron and nickel.
16. A logarithmic scale used to measure the magnitude or strength of an earthquake.
17. The theory that explains the movement of Earth's lithospheric plates over the mantle.