| A | B |
|---|
| the hypothesis that the continents slowly move across Earth's surface | continental drift |
| the name of the single landmass that broke part 200 million years ago and gave rise to today's continents | Pangaea |
| the process by which molten material adds new oceanic crust | seafloor spreading |
| the rigid layer made up of the uppermost part of the mantle and the crust | lithosphere |
| the soft layer of the mantle on which the lithosphere floats | asthenosphere |
| the process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary | subduction zone |
| the movement of a fluid, caused by differences in temperature, that transfers heat from one part of the fluid to another | convection current |
| vibrations that travel through Earth carrying the energy released during an earthquake | seismic waves |
| the force exerted on a surface divided by the area over which the force is exerted | pressure |
| the layer of rock that forms Earth's surface | crust |
| a dark, dense, igneous rock with a fine texture, found in oceanic crust | basalt |
| a usually light-colored igneous rock that is found in continental crust | granite |
| the layer of hot, solid material between Earth's crust and core | mantle |
| the transfer of energy through space | radiation |
| the transfer of heat within a material or between materials that are touching | conduction |
| a layer of molten iron and nickel surrounds the inner core of Earth | outer core |
| a dense sphere of solid iron and nickel at the center of Earth | inner core |
| the amount of mass in a given space | density |
| a trace of an ancient organism that has been preserved in rock | fossil |
| an undersea mountain chain where new ocean floor is produced | mid-ocean ridge |
| a device that determines the distance of an object under water by recording echoes of sound waves | sonar |
| a deep valley along the ocean floor beneath wich oceanic crust slowly sinks toward the mantle | deep ocean trench |
| the transfer of heat by movement of a fluid | convection |
| a section of the lithosphere that slowly moves over the aesthenosphere, carrying pieces of continental and oceanic crust | plate |
| a well-tested concept that explains a wide range of observations | scientific theory |
| the theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle | plate tectonics |
| a break in Earth's crust where masses of rock slip past each other | fault |
| a deep valley that forms where two plates move apart | rift valley |
| a plate boundary where two plates move toward each other | convergent boundary |
| a plate boundary where two plates move away from each other | divergent boundary |
| a plate boundary where two plates move past each other in opposite directions | transform boundary |
