| A | B |
|---|
| Pangaea | super continent that existed 200 million years ago |
| Alfred Wegener | a German meteorologist and geophysicist who originated the theory of continental drift. |
| sea-floor spreading | theory that new ocean crust is formed at the mid ocean ridges by molten lava |
| mantle | the largest interior layer of the Earth that is located between the crust and core |
| crust | the outer most and thinnest layer of Earth |
| inner core | a dense sphere of solid iron and nickel at the center of the earth. |
| outer core | a layer of molten iron and nickel that surrounds the inner core of the Earth. |
| asthenosphere | plastic-like upper layer of the mantle, on which the tectonic plates move. |
| tectonic plates | large sections of Earth's crust and upper mantle, lithosphere |
| plate tectonics | the theory that Earth's crust and upper mantle are broken into sections |
| continental drift | a hypothesis that the continents were a single landmass at one time and have moved across the ocean's floor over time to their present locations. |
| divergent boundary | a boundary between two plates that are moving apart |
| convergent boundary | a boundary where two plates are moving toward each other |
| transform boundary | a boundary where two plates are moving past each other |
| convection current | the cycle of heating, rising, cooling and sinking |
| subduction zone | an area where the denser converging plate desends or sinks under a less dense converging plate |
| San Andreas Fault | an example of a transform fault boundary |
| mid-ocean ridge | an example of a divergent boundary in ocean crust |
| East African Rift | an example of divergent boundary in continental crust |
| Marianas Trench | the deepest spot in any ocean, an example of converging oceanic plates |
| Himalaya Mountains | example of boundary where two continental crust collided |
| sonar | a device that determines the distance of an object under water by recording echoes of sound waves. |
| ridge push | the process by which magma rises through an ocean floor fissure, hardens, and its elevated weight pushes the adjacent seafloor towards a trench |
| slab pull | the process by which a subducting tectonic plate pulls the trailing seafloor down into the mantle |
| subduction | the process by which one tectonic plate sinks below another, returning to the mantle, where the rock is re-melted. |
| rift valley | a deep valley caused by the rifting (splitting) of a continental tectonic plate. |
| fossil | a trace of an ancient organism that has been preserved in rock. |
| buoyant | less dense and thus able to float |
| hot spot | a stationary plume of magma that forms a rising column that heats and fractures the lithosphere above it |
| Glossopteris | an extinct seed fern found as fossils throughout India, South America, southern Africa, Australia, and Antarctica. |
| Lystrosaurus | an extinct a mammal-like, herbivorous reptile found as fossils in Africa, southeast Asia and Antarctica, and from the lower Triassic. |
| Mesosaurus | an extinct freshwater swimming reptile found as fossils on the east coast of southern Brazil and the west coast of Africa. |
| Cynognathus | an extinct Triassic land reptile found as fossils in South America and South Africa, and from the Lower Triassic. |
| fault | a break or crack in Earth's lithosphere along which the rocks move. |
| isochronic map | a map that shows the points that have the same age, that is, they were formed at the same time. |
| magnetic reversal | the switching of Earth's magnetic poles such that the north magnetic pole becomes located at the south magnetic pole's position and vice-versa. |
| Harry Hess | an American geologist who studied mid-ocean ridges using echo-sounding surveys of the Pacific and ultimately developed the theory of sea-floor spreading. |
| ocean trench | a deep valley along the ocean floor beneath which oceanic crust slowly sinks toward the mantle. |
| folded mountain range | mountains that were formed from two converging, buoyant continental tectonic plates that crumple and fold upward |
| volcanic mountain range | mountains that were formed by a tectonic plate subducting under another plate |
| Andes Mountains | an example of a volcanic mountain range and located along the western coast of South America |
| magma plume | a large body of magma below the Earth's surface |
| island acr | a chain of volcanoes, with arc-shaped alignment, situated parallel and close to a boundary between two converging tectonic plates. |
| Mid-Atlantic ridge | an example of an mid-ocean ridge that is located in the Atlantic ocean |
| Ring-of-Fire | an area around the Pacific Ocean where 75% of active and dormant volcanoes are located and 90% of earthquakes occur |
