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How do we know that the mantle is mostly solid and not molten ? |
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Definition
seismic shear waves pass through it |
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according to the principle of isostatic equilbrium a section of plate will be more buoyant (ride higher on the mantle) If it is? |
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Definition
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Beneath which of these locations is the crust likely to be thinnest? |
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Definition
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why are there ocean basins? |
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Definition
ocean crust is thinner and denser than continental crust |
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Term
why is the oldest ocean crust only 180 million years old? |
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Definition
All older ocean crust has been subducted |
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Term
if there were no other sources of heat the increase of pressure with increasing depth in the earths interior woul cause temp to___ and heat to__ |
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Definition
increase...remain unchanged |
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Term
what is required to drive mantle convection? |
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Definition
a heat source and a heat sink |
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Term
How does convecting mantle rock lose heat in order to sink? |
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Definition
by conduction through lithosphere |
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Term
which of the following is not major force driving seafloor spreading? |
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Definition
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Term
the rigid plates of plate tectonics are also known as? |
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Definition
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Term
which of the following is not a piece of evidence that supports the theory of plate tectonics?
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Definition
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Term
why does mantle rock melt as it rises buoyantly? |
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Definition
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Term
why do volcanoes form near subduction zones |
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Definition
water from sub ducting plate causes mantle rock to melt |
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Term
which of these plate boundaries are convergent |
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Definition
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Term
what is the half spreading rate of the east pacific |
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Definition
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Term
which feature is not typically found at the crest of a mid ocean ridge |
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Definition
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Term
if 2 plates overlain by ocean crust meet at a convergent boundary which one will likely subduct? |
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Definition
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Term
choose the correct order of the sediment sizes, from smallest to largest |
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Definition
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Term
according to stokes law which 2 variables would both increase the sinking rate of a spherical particle through a still fluid? |
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Definition
large particle size and high particle density |
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Term
what variable affects the amount of frictional resistance acting on a sinking particle? |
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Definition
particle surface area to volume ratio |
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Term
what type of sediment would you find dominating the middle of the deepest pacific far from land and far from any biologically productive surface waters |
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Definition
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Term
what condition is clcium carbonate more likely to dissolve in seawater |
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Definition
cold water, high pressure |
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Term
the 2 main biogenic minerals found in sediments are |
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Definition
calcium carbonate and opal |
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Term
if you find a pebble size terrigenous grain on te abyssal plain how did it most likely get there |
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Definition
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Term
the water molecule is said to be polar bc it is assymetrical and |
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Definition
has a slight charge at each end |
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Term
what single factor best explains why liquid water has a higher heat capacity than most substances |
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Definition
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Term
where does most of the heat in ocean waters orriginate |
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Definition
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Term
as heat is added to pure ice what happens when its temp reaches 0 c |
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Definition
remains at 0 as ice begins to melt |
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Term
how does waters high latent heat of vaporization moderate air temps |
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Definition
evaporation consumes heat in warm environments and condensation releases heat in cold environments |
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Term
How does waters high latent heat of fusion moderate air temps |
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Definition
melting consumes heat in summer and freezing releases heat in winter |
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Term
why dosent the pressure of the deep ocean increase seawater density very much |
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Definition
liquids are relatively incompressible |
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Term
which of these greenhouse gases account for most of the natural greenhouse effect |
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Definition
water vapor and carbon dioxide |
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Term
assuming the earths heat budget is at steady state what physical law determines the radiating temperature of the planet |
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Definition
amount of radiation emitted depends on temp of emitter |
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Term
solar energy absorbed by the earth is returned to space as |
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Definition
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Term
in computing the energy budget for the earth which of the following is treated as a feedback rather than a direct radiative forcing factor |
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Definition
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Term
characterize the heat absorbed by upper ocean in recent decades |
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Definition
more than absorbed by land |
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Term
the main reason that the earths inner core is solid is its high__. the main reason that the earths crust is solid is its low ___ |
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Definition
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Term
how will negatively buoyant mantle rock tend to move within the mantle |
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Definition
it will sink toward the core |
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Term
the least dense rocks on earth are generally found in |
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Definition
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Term
satellite altimetry can measure seafloor topography because |
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Definition
gravity deforms the sea surface |
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Term
the speed of sound in seawater is about ___than the speed of sound in air |
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Definition
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Term
why is it difficult for oceanographers to "see" through seawater and study the deep sea |
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Definition
electromagnetic radiation is readily absorbed by seawater |
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Term
in what environment do most scientist now think life likely originated? |
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Definition
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Term
the world ocean contains what percentage of H20 at the earths surface? |
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Definition
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Term
the world ocean is said to have an aspect ratio (area compared to thickness or depth) comparable to |
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Definition
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Term
which color of visible light is most efficiently transmitted through seawater |
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Definition
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