| A | B |
|---|
| geologist | A scientist who studies the forces that make and shape planet Earth. |
| geology | The study of planet Earth. |
| constructive forces | A force that builds up mountains and landforms on Earth's surface. |
| destructive forces | A force that slowly wears away mountains and other features on the surface of Earth. |
| seismic waves | A vibration that travels through Earth carrying the energy released during an earthquake. |
| crust | The layer of rock that forms Earth's outer surface. |
| mantle | The layer of hot, solid material between Earth's crust and core. |
| lithosphere | A rigid layer made up of the uppermost part of the mantle and the crust. |
| asthenosphere | The soft layer of the mantle on which the lithosphere floats. |
| outer core | A layer of molten iron and nickel that surrounds the inner core of Earth. |
| inner core | A dense sphere of solid iron and nickel in the center of Earth. |
| heat transfer | The movement of energy from a warmer object to a cooler object. |
| radiation | The transfer of energy through empty space. |
| conduction | The transfer of heat by direct contact of particles of matter. |
| convection | The transfer of heat by movements of a heated fluid. |
| convection current | The movement of a fluid, caused by differences in temperature, that transfers heat from one part of the fluid to another. |
| density | The amount of mass in a given space; mass per unit volume. D=M/V |
| plate | A section of the lithosphere that slowly moves over the asthenosphere, carrying pieces of continental and oceanic crust. |
| scientific theory | A well-tested concept that explains a wide range of observations. |
| plate tectonics | The theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle. |
| fault | A break in Earth's crust where slabs of rock slip past each other. |
| transform boundary | A plate boundary where two plates move past each other in opposite directions. |
| divergent boundary | A plate boundary where two plates move away from each other. |
| rift valley | A deep valley that forms where two plates move apart. |
| convergent boundary | A plate boundary where two plates move toward each other. |
