Plate tectonics
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Created by:
EmmaRodgers1997 on April 3, 2011
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38 terms
Terms | Definitions |
|---|---|
 alfred wegener 1912 | who and when proposed the theory of continental drift |
| pangaea-entire earth | aall the continents where once connected as a super continent called.......but have scince drifted apart |
| puzzle peices (africa and south america) | alfred wegener thought the continents looked like........ |
| fossils of plants and animals | diffrent continents had the same....... of .........and ....... |
| messosaurus | south america and afica both have fossils of this fresh water and land animal, that could not swim that great distance. |
| glossopteris | a plant found on five diffrent continents, not possible for it to travle such distances. |
| glacial scraping patterns | rocks on different continents have the same.......... (west side of africa and east side of south america -neither can sustain glaciers now) |
| composition and age | rocks on different coast are similar in ............. (appalachian mountains same as those found in greenland and western europe) |
| move through | alfred wegener could not explain how continents..........most scientist dismissed it. |
| earths rotation and gravitational force of sun and moon | alfred wegener thought these things caused the continents to move |
| alfred wegener | had issues with his credibility because he was a weather man |
| harry hess | figured out how continents move |
| the mid atlantic ridge | discovered by scientist using sonar to map ocean floor |
| hess 1960 | proposed the theory of sea floor spreading |
| hot less dense material below the earths crust rises towards the earths surface at mid ocean ridge. then it flows sideways carrying the seafloor away from the ridge in both directions. | sea floor spreading thing |
| age of rocks surrounding the ridge (eosfs) | the youngest rocks are closest to the ridge and become older as you move away |
| magnetic clues (eosfs) | the.......feild of earth has reversed throughout history, those reversals are recorded in rocks surrounding the ridge. |
| iceland | the ridge runs throught the country so it is being split apart |
| plate tectonics theory | combines continental drift and seafloor spreading |
| plates | earths crust is broken into sections called ....... |
| athenosphere | plates move on a plastic like layer of the mantle called........ |
| plates | large sections of earths crust, both oceaninc and continental. |
| divergant | 2 plates move apart |
| convergent | 2 plates push together |
| transform | 2 plates slide past each other |
| within the mantle cause movement; hot magma rises and cools when it gets close to the crust, causing a current that causes the plate above it to move | ......convection currents...... |
| earthquakes | occur at all plate boundaries but largest are at transform |
| tsunamies | produced by underwater earthquakes |
| volcanoes | produced at subduction zones (oceanic pushes under continental) produced at divergent bounderies under water |
| montains | produced at convergent boundaries (2 continental plates push together and are forced upward) |
| deep sea trenches | formed when 2 oceanic plates converge and both are pushed back into the mantle |
| rift valley | formed when 2 continental plates pull apart. |
| stretch of under water ridges caused by continually erupting volcanoes | what did scientist find by using echo signals along the ocean floor? |
| strong enough to move continents new crust formed dips back down into interior of the earth | describe seafloor spreading |
| if two collide one is pushed down and melts into magma. destroyed in deep sea trenches | if the sea floor is spreading and earth is not getting any bigger, where is crust being destroyed? |
| earths moveing crust or a peice of crust | what is it meant by a plate? |
| earth quakes. move with earths rotation | what causes plates to move? |
| the atlantic is growing-new crust is being formed at mid atlantic ridge. the pacific is shrinking-crust pushed back down into mantle. it melts in deep sea trenches and subduction zones. | which ocean is growing? which is sinking? explain why. |
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