| A | B |
|---|
| abyssal plain | large flat area on the ocean floor |
| continental rise | part of a continental margin that separates a continental slope from the ocean floor |
| continental shelf | relatively flat part of a continental margin that is covered by shallow water |
| continental slope | part of the continental margin at the edge of a continental shelf where the ocean floor plunges steeply |
| guyot | flat-topped seamount |
| lithosphere | part of the Earth's surface covered by land: solid, topmost part of the Earth |
| mantle | layer of the Earth directly above the outer core and beneath the crust, containing molten rock |
| seamount | underwater volcanic mountain on the ocean floor |
| shoreline | boundary where the land and the ocean meet |
| submarine canyon | deep, V-shaped valley cut in the rock through a continental shelf and slope |
| trench | long, narrow crevice, or crack, along the edge of the ocean floor |
| cinder cone | a volcano made mostly of cinders and other rock particles that have been blown into the air |
| composite volcano | a volcano built of alternating layers of rock particles and lava |
| compression | type of stress that squeezes rocks together |
| convection current | a movement of material caused by differences in temperature |
| convergent boundary | a plate boundary at which plates come together |
| crust | the surface layer of the Earth |
| divergent boundary | a plate boundary at which plates move apart |
| dome | a raised area shaped roughly like the top half of a sphere, often formed by magma pushing upward on the rock layers above it |
| earthquake | the shaking and trembling that results from the sudden movement of part of the Earth's crust. |
| epicenter | the point on the Earth's surface directly above the focus of an earthquake |
| fault | a break or crack along which rocks move |
| focus | the underground point of origin of an earthquake, where the rocks break and move |
| fold | a bend in a rock |
| fossil | the preserved remains or traces of an ancient organism |
| hardness | the ability of a mineral to resist being scratched |
| igneous | formed from molten rock |
| inorganic | not from living things or the remains of living things |
| isostasy | the balancing of the downward force of the crust and the upward force of the mantle |
| lateral fault | a fault along which the blocks move horizontally past each other |
| lava | molten rock at the Earth's surface |
| lithosphere | the topmost solid part of the Earth, which is composed of the crust and some of the mantle |
| magma | the layer of the Earth that extends from the bottom of the crust to the outer core |
| metamorphic | changed in form as a result of chemical reactions, hear and/or pressure |
| midocean ridge | an undersea mountain chain where new ocean floor is produced; a constructive (divergent) plate boundary |
| mineral | a naturally occurring, inorganic solid that has a definite chemical composition and crystal shape |
| ocean-floor spreading | the process in which old ocean floor is pushed away from a miocean ridge by the formation of new ocean floor |
| Pangaea | the single giant landmass that existed more than 200 million years ago and that gave rise to the present-day continents |
| plate | in plate tectonics, one of the moving, irregularly shaped slabs that make up the Earth's lithosphere |
| plateau | a large area of flat land that is raised high above sea level and that consists of horizontal rock layers |
| primary wave (P wave) | a push-pull seismic wave, which can travel through solids, liquids and gases; P waves are the fastest type of seismic wave |
| Ring of Fire | the earthquake and volcano zone that encircles the Pacific Ocean |
| rock cycle | the interrelated processes that cause the continuous changing of rocks from one kind to another |
| rock | a hard substance composed of one or more minerals |
| secondary wave (S wave) | a side-to-side earthquake wave, which can travel ONLY through solids; S waves are slower than P waves but faster than L waves |
