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37 Cards in this Set
- Front
- Back
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bathymetry |
underwater topography (water depth) |
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morphology |
shape |
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seismicity |
earthquakes |
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continental drift lead to |
plate techtonics theory. continental drift theory was rejected |
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Composition of: -core -mantle -crust |
core- iron/nickel. inner=solid outer=liquid 31.5%
mantle- dense rock, mostly solid. brittle & rigid 68.1%
crust- rocky, solid, thin. continental vs. oceanic .4% |
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lithosphere |
crust and upper mantle. brittle and rigid because its cold
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asthenosphere |
upper mantle. plastic and ductile. warmer
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mesosphere |
remainder of the mantle. more rigid |
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continental crust |
thick. Granite (less dense)
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oceanic crust |
thin. Basalt (more dense) slides under continental crust |
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continental margin |
drowned edges of cont. - continental shelf = flat and shallow - continental slope = steeper - continental rise = sediment layers
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Mid ocean ridges |
continuous submarine mtn. range winds through all ocean basins
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deep ocean basins |
ocean floor that lies deeper than 2,000 meters below sea level -trenches, sea mounts = parallel -ridges & rises, fracture zones = perpendicular |
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Guyots |
flat top seamount from wave erosion which means it was once above water. 1. sea level rose, had to rise everywhere. - no 2. guyots sank. - yes |
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extrusive rock |
magma has come out of volcano ex. pillow basalts - only underwater |
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atolls |
(coral reefs: shallow and warm) grow on volcano |
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Trench |
deep. Mt. Everest smaller than mariana |
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topography |
shape of land (crust) above sea level. sea level = 0 |
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weighted line |
measuring technique. hemp and a rock. fathom - 6 ft.
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echo-sounding |
measuring technique. sound bouncing off sea floor. Need to know time and speed of sound in water
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side scan sonar |
measuring technique. using sound to the sides- by using a tow fish (shadow areas) |
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multibeam sonar |
measuring technique. using multiple tows. found a meandering stream |
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altimetry |
measuring technique. using sattelites to measure seafloor. seamounds attract h2o, trenches |
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seismic reflection |
measuring technique. reflects off different density surfaces
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pangaea |
super continent 240 mill years old 1912 Greek word for "All Earth" |
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panthalassa |
super ocean |
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gondwanaland |
southern part of pangaea |
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laurasia |
northern part of pangaea |
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accretionary prism |
sediments that got bulldozed and didnt make it down to the asthenosphere. (shaving cream example) |
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Oceanic-Oceanic |
-trench, subduction, benioff zone, volcanic chains (seamounts) -volcanic island chains ex. japan -composition: Basalt (mafic) & Andesite (intermediate) |
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Oceanic-Continental |
-trench, subduction, benioff zone -Volcanic island chains, explosive ex. Andes -composition: Andersite (intermediate) & Rhyolite (felsic) -More silica in magma, the thicker the magma is thick viscosity |
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continental-continental |
no subduction, trench, benioff zone, or volcanos. suture zone- the seam of 2 continents |
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viscosity |
-low viscosity = fluid flows -high viscosity = resistance to flow, keeps gas from escaping |
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slab pull |
gravity pulls the slab into the asthenosphere, shallow slab subduction steeper slab subduction |
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divergent plates |
heat breaks up the plate, rising conviction cells, friction drag. gravity sliding |
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Hotspots |
when a volcano isn't erupting, it gets old and contracts. bigger volcanos are younger. distance from hotspot / time = velocity |
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convergent plates |
descending convection cells. slab pull |
