| Meaning |
Term |
| The thin, outermost layer of the Earth, or the uppermost part of the lithosphere |
crust |
| the outermost, rigid layer of the Earth that consists of the crust and the rigid upper part of the mantle |
lithosphere |
| the strong, lower part of the mantle between the asthenosphere and the outer core |
mesosphere |
| the soft layer of the mantle on which pieces of the lithosphere move |
asthenosphere |
| the liquid layer of the Earth's core that lies beneath the mantle and surrounds the inner core |
outer core |
| soild, dense ball of iron |
inner core |
| the theory that continents can drift apart from one another and have done so in the past |
continental drift |
| all the Earth's land masses joined together were once called this |
Pangaea |
| as tectonic plates move away from each other, the sea floor spreads apart and magma rises to fill in the gap |
sea-floor spreading |
| the theory that the Earth's lithosphere is divided into tectonic plates that move around on top of the asthenosphere |
plate tectonics |
| process by which hot material from deep within the Earth rises while cooler material near the surface sinks |
convection |
| when two tectonic plates push into one another, this is the boundary where they meet |
convergent boundary |
| when two tectonic plates move away from each other this is the boundary they create between them |
transform boundary |
| this is used to measure the rate of tectonic plate movement |
Global Positioning System or GPS |
