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42 Cards in this Set

  • Front
  • Back
Central ideas: Cylcles of the Earth
1) Earth materials move in cycles
2) A change in one cycle affects the other cycles
Resevoirs of water
Oceans, lakes, rivers and streams, ice caps and glaciers, stmosphere and clouds, groundwater and ground ice, living matter
Modes of water movemnet b/t resevoirs
precipitation, evaporation, sublimation, transpiration, flow due to gravity
Ocean Currents
redistribute solar heat in sea water across the Earth; affects Earth's weather and climate
Current systems involving return flow of cold water to lower latitudes; mainly occurs in large ocean basins
colder deep water flows up at coastal areas due to wind energy pushing surface water away from land
Bottom currents
cold water from polar areas that flows down to sea floor and toward the equator; cold water is colder the more dense
Saltiness of the Ocean
due to weathering of rocks on land, and transportation of dissolved elements into the sea; saltiness at present level since 3.5 billion years ago
Removal of Salt from Ocean
evaportaion of seawater causes saturation and then precipitation of salt crystals; organisms in the sea also take up dissolved minerals
Return of Salt to the SEA
sediments of the ocean form layers of sedimentary rock that are pushed up into folded mountains, eroded away and transported to the ocean via rivers and streams; subduction may also result in melting of these sediments and chemical return to the ocean via volcanoes
ice age
periodic cycle of glacial and interglacial stages (intervals of geologic time)
Earth's Ice Ages
Pleistocene (4mya - present)
Pnsylvanian - Permian (350 - 250 m.y.a.)
Ordovician - Silurian (460 - 430 m.y.a.)
Proterozoic (800 -600 m.y.a.)
Recent glacial stages
Wisconsinian (75,000 to 11,000 yr ago)
Illinoisan (265,00 to 125,000 yr ago)
Kansan (435,000 to 300,000 yr ago)
Nebraskan (1.8m.y. to 500,000 yr ago)
Effects of glacial stages
- Sealevel drops due to ice caps
- Glaciers move across the land cutting deep U-shaped valleys
- Transport vast amounts of soil and rock
Effects of interglacial stage
- Sea level rises
- Shorelands move inland
- Land rises due to removal of weight of ice caps and glaciers
- Water takes over as main erosional agent on land
Milankovitch theory of ice ages
variation in earth's rotation and orbit make slight variation in total amount of solar radiation absorbed by Earth's atmosphere
Milankovitch factors
23,000 year cycle in the wobble of the Earth's axis
change in axail tilt over time from 21.5 degrees over a 41,000 year cylce
change in shape of Earth's orbit caused by other planet's gravity (100,000 years)
short term variation in the state of the atmosphere at a given time and place
long pattern of weather for a given region
weather variables
temperature (affects atmospheric density)
pressure (lateral variations cause movement of weather systems)
low pressure system
warm moist air
high pressure system
cooler dryer air
jet streams
boundary zones between pressure systems in Earth's atmosphere
water content in air
percent and type of clouds
atmpospheric circulation
the effect of rotation of Earth and solar heating
northern hemisphere
northern trade winds
prevailing westerlies
polar wind belt
soutern hemisphere
southeastern trade winds
prevailing westerlies
polar wind belt
tropical storms
severe storms that start as low pressure systems over warm ocean water; have cyclonic movement; wind 50 to 300 km/hr
strong tropical storms of the Atlantic
strong tropical storms of the Pacific
small scale, violent, rotating funnels of air; winds 300 to 500 km/hr
El Nino
4 to 7 year cycles of weather in Northern hemisphere; due to winds blowing across the Pacific; causes unusually warm waters in equatorial areas and much rain
La Nina
the opposite of El Nino (cold waters... dry conditions)
Greenhouse world
geological times of high average global temperature
icehouse world
geologic times of low average global temperature
igneous rocks
rocks that solidified from liquid rock (magma)
sedimentary rocks
rocks made of grains and crystals from other rocks; rock-weathering causes rocks to disintegrate and decompose forming sediments in sedimentary rocks
metamorphic rocks
rocks that form by solid-state changes in pre-existing rocks that have been heated and put under high pressure (but not melted)