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EarthVocab1&2
Earth
Question | Answer |
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Lithosphere | layer of earth made up of crust and the rigid part of the upper mantle |
Asthenosphere | layer in earth’s upper mantle that is soft because it is close to melting |
Tectonic plate | 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 in 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 |
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 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 | 1. Geological Time Scale- the scale that divides Earth’s history into intervals that are defined by major events or changes on Earth |
Inner Core | innermost hottest part as detected by seismological studies, is a primarily solid sphere about in radius, only about 70% that of the Moon. It is believed to consist of an iron-nickel alloy, and may have a temperature similar to the Sun's surface. |
Outer core | a liquid layer layer about 2,260 kilometers thick composed of iron and nickel which lies above the Earth's solid inner core and below its mantle. |
Mantle | The region of the earth's interior between the crust and the core, believed to consist of hot, dense silicate rocks (mainly peridotite) |
Crust | # The outermost layer of rock of which a planet consists, esp. the part of the earth above the mantle |
Mid-ocean ridge | Underwater mountain system that consist of various mountain ranges |
Convection | The movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of , which consequently results in transfer of heat |
Transform boundary | A transform boundary is a boundary in which two plates (portions of Earth’s lithosphere) slide past each other without creating or destroying lithosphere |
Convection current | a current in a fluid that results from convection |
Divergent boundary | In plate tectonics, a divergent boundary or divergent plate boundary (also known as a constructive boundary or an extensional boundary) is a linear feature that exists between two tectonic plates that are moving away from each other. |
Convergent boundary | Where two plates are moving together |
Continental-continental collision | Continental collision is a phenomenon of the plate tectonics of Earth that occurs at convergent boundaries |
Oceanic-oceanic subduction | Occurs when ocean crust sinks under continental crust, it sinks because it's colder and denser,at these sites, deep-ocean trenches also form along with coastal . |
Oceanic-continental subduction | In the scope of lithospheric plate movements, both boundaries are areas where the more dense of the colliding plates slides under the lighter one, and moves |