| A | B |
|---|
| geologist | a scientist who studies the forces that make and shape planet Earth |
| rock | the material that forms Earth's hard surface |
| geology | the study of planet Earth |
| constructive force | a force that builds up mountains and landmasses on Earth's surface |
| destructive force | a force that slowly wears away mountains and other features on the surface of Earth |
| continent | a great landmass surround by oceans |
| seismic wave | a vibration that travels through Earth carrying the energy releases during an earthquake |
| pressure | the amount of force pushing on a surface or area |
| crust | the layer of rock that forms Earth's outer surface |
| basalt | a dark, dense rock with a fine texture, found in ocean crust |
| granite | a usually light colored rock that makes up most of the continental crust |
| mantle | the layer of hot, solid material between Earth's crust and core |
| lithosphere | a rigid layer made of the uppermost part of the mantle and 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 heat from a warmer object to a cooler object |
| radiation | the transfer of heat through empty space |
| conduction | the transfer of heat through solid materials |
| convection | the transfer of heat by movements within a heated fluid |
| density | the amount of mass in a given space/ mass divided by volume |
| convection current | the movement of a fluid, causes by differences in temperature, that transfers heat from one part of the fluid to another |
| Pangaea | the name of the single landmass that broke apart 200 milllion years ago and gave rise to today's continents |
| continental drift | the hypothesis that the continents slowly move across Earth's surface |
| fossil | a trace of an organism that has been perserved in rock |
| mid-ocean ridge | the undersea mountain chain where new ocean floor is produced |
| sonar | a device that determines the distance of an object under water by recording echoes of sound waves |
| sea-floor spreading | the process by which molten material adds new oceanic crust to the ocean floor |
| deep-ocean trench | a deep valley along the ocean floor through which oceanic crust slowly sinks toward the mantle |
| subduction | the process by which oceanic crust sinks through a deep-ocean trench and back into the mantle/occurs at convergent plate boundaries |
| plate | a section of lithosphere that slowly moves, 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 crust 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/forms at divergent plate boundari |
| convergent boundary | a plate boundary where two plate move toward each other |
| Alfred Wegener | proposed the theory of continental drift |
| Magma | molten rock beneath Earth's surface |
| submersible | a small submarine used for research |
| lava | molten rock on the Earth's surface |
