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49 Cards in this Set
- Front
- Back
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how old is the earth |
4.6 billion years old |
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Describe radiometric dating |
Determining age of geological samples by measuring their abundance of radioactive isotopes |
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What is the tropic of cancer |
When the sun stands above 23 1/2 degrees north |
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What is the tropic of capricorn |
When the sun stands above 23 1/2 degrees south |
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What is the latitude of the arctic circle |
latitude of 66 1/2 degrees south |
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What is the latitude of the antarctic circle? |
66 1/2 degrees south |
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Describe Earth's shape |
a spherical shape that is flatter at the poles and longer around the equator |
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What is longitude? |
Up and down |
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What is latitude? |
left and right
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What are great circles? |
All longitude lines and the equator |
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what percent of earths surface is water? |
71% |
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What is residence time? |
How long a molecule can stay in water. volume/rate replacement |
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describe p-waves |
PRimary waves, travel faster than any other seismic wave, the 1st waves to arrive at location |
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Describe s-waves |
Secondary waves, Slower than primary waves but faster than surface waves |
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What is the MOHO? |
upper surface of the mantle |
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What is the crust? |
Earths surface |
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What is the mantle? |
Beneath the crust |
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What is the core? |
the center of earth |
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What is the lithosphere |
Rigid surface layer consisting of the crust and upper mantle. Plate tectonics chill here |
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What is the athenosphere? |
The soft plastic region under the lithosphere |
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What is the mesosphere? |
Stiff plastic region under the athenosphere |
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Produce some evidence for cont drift |
The conts look like they fit together, fossils, mountain ranges of similar age |
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What is a mid ocean ridge and how are they produced? |
Rosing hot mantle that elevates forming a ridge. |
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Where do shallow earthquakes occur? |
ridges |
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where do deep earthquakes occur? |
ocean trenches |
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What are subduction zones? |
older seafloor |
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What are spreading centers? |
New seafloor |
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Describe a divergent plate and what it creates |
Plates move apart, create mid ocean ridges |
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Describe a convergant plate and what it creates |
Plate collision. form mountain ranges and ocean trenches |
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Describe a transform boundary and what it creates |
Plates slide past each other forming fault lines |
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What is a hotspot? |
Surface expression of rising hot mantle
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What is spreading rate? |
Rate at which two plates move away from each other |
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How does an island chain form? |
when oceanic lithosphere moves over a hotspot |
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What is biogenous sediment? |
sediment arriving from organisms |
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What is cosmogenous sediment? |
arrives from space |
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What is hydrogenous sediment? |
arriving from water |
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What is lithogenous sediment? |
sediment arriving from prexisting rocks |
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name some irregular behaviors of water |
high freezing/boiling point, high heat capacity, can turn to liquid, solid, and gas |
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What makes water become more dense? |
Colder water and saltier water |
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What is the global surface salinity? |
between 32-38 ppt |
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list 5 natural occurrences that control salinity |
evaporation, precipitation, freezing, thawing, runoff |
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What is the density of pure water? |
1000 kg/m3 |
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List the 6 major ions that make up 99% of water |
calcium, sodium, magnesium, Potassium
2 anions= chloride and sulfate |
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What is the mixing time of the ocean? |
1000 years |
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How can you change the salinity of seawater? |
Add/remove water or dissolved substances |
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What is the pynocline? |
In between the surface box and deep sea box |
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photosynthesis produces: |
O2 |
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Respiration produces: |
CO2 |
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What is the pH of seawater? |
8
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