Question | Answer |
Lithosphere | layer of earth made up of crust and rigid part of the upper mantle |
Asthenosphere | layer in earth's upper mantle that is soft because it is close to melting |
Tectonic Plates | one of large moving pieces of Earth's lithosphere (oceanic/continental) |
Continental Drift | hypothesis that Earth's continents move on Earth's surface |
Pangaea | hypothetical super continent that included all the land masses of Earth, broke apart 200 million years ago |
Theory of Plate Tectonics | theory stating that Earth's lithosphere is broken into huge plates that move and change size over time |
Rift Valley | deep valley formed as tectonic plates move apart, such as along a mid-ocean ridge |
Magnetic Reversal | switch in the direction of the Earth's magnetic field so that magnetic north and south switch |
Hot Spot | area where a column of hot material rises from deep within the mantle and heats the lithosphere, causing volcanic activity |
Subduction | when oceanic plate sinks under another plate in Earth's mantle |
Inner Core | a ball of hot, solid metals |
Outer Core | a layer of liquid metals that surrounds the inner core |
Mantle | the layer of rock between Earth's outer core and crust, in which most rock is hot enough to flow in convection currents; Earth's thickest layer |
Crust | a thin layer of cool rock |
Convection Current | a circular pattern in which material is heated and rises in one area, then cools and sinks in another area, flowing into a continuos loop |
Divergent Boundary | a boundary along which two tectonic plates move apart, characterized by either a mid-ocean ridge or a continental rift valley |
Convergent Boundary | a boundary along which two tectonic plates push push together, characterized either by subduction or continental collision |
Continental-Continental Collision | a boundary along which two plates carrying continental crust push together |
Mid-Ocean Ridge | a long line of sea floor mountains where new ocean crust is formed by a volcanic activity along a divergent boundary |
Convection | the transfer of energy from place to place by the motion of heated gas or liquids |
Transform Boundary | a boundary along which two tectonic plates scrape past each other, and crust is neither formed nor destroyed |
Oceanic-Oceanic | a boundary along which a plate carrying oceanic crust sinks beneath another plate with oceanic crust |
Oceanic-Continental Subduction | a boundary along which a plate carrying oceanic crust sinks beneath a plate with continental crust |
Fossil | an object that is a trace or remains of living things from the past |
Original Remains | fossils that are the actual bodies or body parts of an organism
Ex: Bones |
Ice Core | a sample of earth that is taken in a tube and shows the layers that have built up over thousands of years |
Relative Age (Dating) | the age of an even or object in relation to other events or objects (younger or older) |
Absolute Age (Dating) | the actual age in years of an object or event |
Index Fossil | fossils of organisms that were in common, lived in many areas, and existed only during a certain time span |
Half-Life | the length of time it takes for half of the atoms of a radioactive element to change to another form |
Uniformitarianism | the theory that Earth is an always changing place and that the same forces of change from the past are at work today |
Geological Time Scale | the scale that divides Earth's history into intervals that are defined by major events or changes on Earth |