Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
plate tectonics
chap 9 review
| Term | Definition |
|---|---|
| plate tectonics | sold plates of lithosphere "float" around earth on soft plastic asthenopshere, continental drift |
| caldera ex) crater lake | forms when volcano erupts violently and collapses into its empty magma chamber |
| Alfred Wegener | proposed theory of plate tectonics in late 60s |
| asthenosphere | below lithosphere, floats because differential heating of mantle |
| lithosphere | rigid outermost shell, brittle solid upper portion of the crust |
| 4 types of plate boundaries | spreading, converging, , transform |
| spreading/divergent plate boundary | when 2 lithosphere plates pull apart when a crack occurs it fills with magma lava and solidifies |
| Spreading/divergent onland | creates rift valleys with normal faulting |
| spreading/divergent at sea | makes sea floor spreading and used to date sea floor |
| midoceanic ridge | the central belt of submarine mountains where two plates seperate, |
| How is a midoceanic ridge created? | sea floor spreading causes lava to form at its centers which creates oceanic crust OR continental plates spread apart and a new ocean basin is created between them |
| convergent plate boundary | boundary where any two lithospheric plates come together |
| How is a convergent boundary created? | a plate slides under another (subduction) OR plates collide creating a mountain range |
| transforms boundary | a boundary where two lithospheric plates slide past each other |
| How are transform boundaries made? | plates grind past each otheralong vertical fractures |
| continental suture | continents united after collision |
| pangea | super continent existed 300 million years ago |
| gandwana | southern super continent |
| laurasia | northern super continent |
| the alps | collision of african and eurasian plates |
| himilaya | collision of austral- indian and eurasian plates *fastest moving plate on planet |
| potassium argon dating | dated sea floor is evidence of plate tectonics |
| how does potassium argon dating work? | potassium 40 decays over time into argon 40- the amount of decay lets us know the date |
| half life | used to date older things, when half of a parent isotope decays into the daughter isotope |
| oceanic trench | when there is a rising and sinking plate and the descending plate pulls material into the asthenosphere- deep part of boundary between continental and oceanic crust |
| subduction | denser oceanic crust dives under less dense continental crust |
| what is the evidence of plate tectonics | Potassium argon dating and the age of the sea floor, pangea, continental drift, volcanoes tsunamis and earthquakes, fossils, rock types |
| sea-floor spreading | new oceanic crust is formed from volcanic activity and then gradually moves away from the ridge *helps explain continental drift |
| epicenter | the location of the earths surface directly above where a fault slipped to produce an earth quake |
| magnitude | the amount of energy released by an earthquake |
| earthquake | trembling and shaking of the ground, produced by movements along faults |
| volcano | built by hardened lava, tephra, and volcanic ash usually domed shaped |
| hotspot | center of volcanic activity thought to be located over a rising mantle plume |
| stratovolcano (layered+strato) | constructed by layers of lava and volcanic ash |
| shield volcano | low large dome like accumulation of basalt lava flows emerging from long radial fissures on flanks |
| caldera | when a stratovolcano explodes destroying center portion of volcano it creates central depression |
| cinder cone | small volcano formed when frothy magma is ejected under high pressure from narrow vent producing tephra |
| flood basalts | basalt layers accumulated by emerging from numerous vents and fissures |
| geomorphology | study of landforms and the process that creates them |
| felsic magma | composed of because higher viscosity builds pressure |
| felsic volcano | build pressure and explode |
| mafic volcano | ooz lava |
| lahars | volcanic mud flow |
| pyroclastic flow | superheated cloud of gas and ash incinerates everything in path- well over 1000F at its center, travels 150mph |
| Mt. St. Helens | major eruption killing 57 people had lateral blast going sideays |
| tephra | produced by volcanic eruption, clastic volcanic material |
| initial landforms | endogenic constructed by forces within the earth |
| sequential landforms | exogenic constructed with forces outside of the earth by wind glaciers gravity etc |
| erosional | land there because something else eroded |
| depositional | land deposited there |
| characteristics of a volcano | endogenic, initial landform BUT the greenery etc on top of volcano is exogenic, sequential |
| guyot | sea mount |
| hawaii | example of hotspot plumes forming chains of volcanic island and sea mounts |
| mafic magma | quiet low viscosity and less gases |
| volcanoes on oceanic plates are less explosive | |
| Yellowstone | supervolcano that erupts every 600,000 years |
| hotspots- on land | more felsic and violent |
Created by:
1738400229818217
Popular AP Human Geography sets