earthquakes & volcanoes

6. Dense ball of solid material at the center of he Earth
10. plate that moves an inch every year.
13. A plate boundary where two plates move toward each other
14. The process by which molten material adds new oceanic crust to the ocean floor
15. rumbling tectonic plate

1. Cause the plates to move; between the lithosphere and the asthenosphere
2. a large mountain that builds up and releases ho
3. Alfred Wegener's hypothesis that the continents were once one huge land mass but have since then drifted apart
4. A plate boundary where two plates move away from each other
5. Thickest layer of the Earth; it consists of two layers - the lithosphere and the asthenosphere
7. Theory that pieces of the Earth's lithosphere are in motion,driven by convection currents in the mantle
8. A layer of molten iron and nickel that surrounds the inner core of the Earth
9. The name of the single landmass that broke apart about 225 million years ago
11. A plate boundary where two plates grind against each other, moving it different directions
12. The undersea mountain mountain chain where new ocean floor is produced; a divergent plate boundary