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175 Cards in this Set
- Front
- Back
What is the core of the earth
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densest and heaviest material of the earth
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what does the rotation of the earth effect in the core?
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the outer layer, made of liquid, that when spinning creates Earths magnetic field
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what is the difference between the outer and inner core of the earth
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the inner core is solid and made of nickel and iron; the outer core is liquid material
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What is the mantle
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the layer of rock below the crust
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How does convection work in the mantle
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hot rocks rise up through the cooler layers; as they cool they flow sideways before sinking again into the core
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Convection in the asthenosphere usually causes:
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volcanic activity
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The asthenosphere is the hardest part of the mantle. True or False
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False; it is the softest and most easily deformed
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The crust is part of...
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the lithosphere
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What is the Moho?
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the lower boundary of crust where seismic waves increase in speed as they enter the upper mantle
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How many major crustal plates are there?
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Seven
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Denser continental plates do what?
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gooes over lighter plates.
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Oceans plates go over continental plates? True Or False
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False; they go over continental plates because they are denser
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Rocks formed by the cooling of magma
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Igneous
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Fossil Marine organism ------>Limestome------>Marble; explain how each was formed
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the fossil marine organisms were compacted together in convection to create the limestome. Intense heat and pressure changed the limestone to marble
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Intense pressure or heat that changes a rock is called a ________________ rock
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Metamorphic
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how are sedimentary rocks formed?
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through the combination of other rocks through convection (compaction and combining of other rocks)
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When magma comes up from below the Earth's surface, what is it referred to as?
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Lava
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Sima
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Fe Mg (Si O2)
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Sial
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Al (Si O2)
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What two components make up the Earth's crust?
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Sima and Sial
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All rocks were originally igneous. True or False
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True
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What are two characteristics of oceanic rocks?
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denser rocks, younger
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What are two characteristrics of continents?
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less dense, lighter rocks; older
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What are the basic components of continents?
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interior shield, stable platform, internal plain, folded mountain belt
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What was the supercontinent that united all land masses 200 million years ago called?
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Pangaea
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Who gave the Continental Drift theory?
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Alfred Wegener
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What does the continental drift theory state?
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that continents were originally together in one landform, but have broken apart.
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What was the evidence that was given for continental drift?
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the geographic fit of the continents, fossils of same species were found on same aged rocks in different continents, mountains of the same age and rock type were found on both sides of the atlantic ocean, radio transmissions over the atlantic took longer each year
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Continental Drift relies on what two principles?
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Plasticity-land can bend and change
isostasy-buoyancy of the earth as it floats in the asthenosphere; the heavier the weight, the deeper it floats |
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What were two problems facing the continental drift theory?
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people were convinced that the earths crust was hard; they couldnt conceive that plasticity and isostasy were possible
no suitable mechanism could be thought of to move such large landmass |
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What is the sea flood spreading theory?
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oceans were pulling apart from each other, as this occurs new material surfaces
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Who popularized the sea flood spreading theory?
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Harold Hess, in 1960
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The sea floor spreading theory helped confirm what theory?
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plate tectonic theory
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What was the plate tectonic theory?
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crustal rearrangement due to Earths internal energy (convection cells drive movement of plates)
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Iron grains in rocks will cool and point to where?
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earth's magnetic field
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Paleomagnetism confirmed what theory?
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Plate Tectonic Theory
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What does the orientation of iron grains show and with what does it show this with?
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how earths magnetic field has changed; magnetic stripes
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Divergent plates do what?
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move away from each other
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What happens when divergent plates move apart from each other?
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the asthenosphere is stretched and thinned; creates mid-ocean ridges and flood basalts-volcanos and earthquakes common
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How fast do continental plates move?
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the speed that fingernails grow
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How do plates compensate for the stretching of the asthenosphere?
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by constantly smashing and reforming into each other
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Plates that are coming together are...?
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convergent plates
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Name the three different types of convergent plate boundaries
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Oceanic-Continent
Oceanic-Oceanic Continent-Continent |
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Subduction of denser ocean plate is what type of convergent plate boundary?
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Oceanic-Continent
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Subduction of denser ocean plate below another is what type of convergent plate boundary?
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Oceanic-Oceanic
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Compression and warping occur in this type of convergent plate boundary?
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Continent-Continent
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The St. Andreas fault is an example of?
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Lateral Plate Contacts...aka. Transform Faults
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What is a transform fault?
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when plates slide past one another
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Large rivers that go through dryland which originate in wetter climates
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Exotic Streams
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The Nile River and Colorado River are examples of
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Exotic Streams
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Intermittent Stream
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stream that flows only for short periods in the year; initiated by rain
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What is the resistant rock left after sediment and rock around it arodes?
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Inselberg
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Waht shape are alluvial fans?
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fan shaped
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Where do alluvial fans form and what does a decrease in slope mean?
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alluvial fans form at the mouth of canyon. A decrease in slope decreases the flows transport capacity.
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Episodic Streams follow what kind of floods?
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flash floods
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Interior Drainage
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all drainage runs into closed basins-dry lake beds
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Scarp Terrain is also called
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Mesa Terrain
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An example of a mesa scarp terrain
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The Grand Canyon
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Delfation hollows are formed by
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euolian processes (wind erosion)
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Fine material removed, leaving dish shaped feature is called
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Deflation hollows
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Why are desert pavements covered in cobble stone?
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smaller particles carried away and eroded by winds; also, water erosion
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What is an erg?
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A vast sea of sand (Sahara Desert)
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Sand Dune
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caused by wind movement; can be live or fixed
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What side does a slip face appear on a sand dune?
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the leeward side
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Loess
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blanket of sediment that forms cliffs; found in desert, dry floodplains, glacial outwash
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Two types of erosion
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deflation, abrasion
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Deflation involves what
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loose particles picked up by the wind; cobble ground is left after finer materials are blown away
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Abrasion involves what
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near ground surface, scult desert features
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Two types of transportation are
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saltation and suspension
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Saltation transports small particles. True or False
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False; saltation transports the large particles
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Suspension transports small particles. True or False
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True
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A sand dunes shape is determined by what factors
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sand amount available, strenght and direction of the wind, and amount of vegetation covering
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A barchan dune is what shape?
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crescent shaped
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A wavy dune is what type of dune?
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Transverse
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Longitudinal dunes are short and wide. True or False
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False; longitudinal dunes are long and narrow
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Loess are made of?
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salt and clay
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moving swell or ridge on the surface of a solid or liquid without the medium of a gas
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wave
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Long Term Sea Level Changes
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Eustatic; Isostatic, Tectonic
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change in world wide sea level due to volume of ice on Earth's surface
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Eustatic
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change of continent position relative to sea level; land is still rebounding from when topped with glacial ice
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Isostatic
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changes in local land position relative to sea
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Tectonic
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Short Term Seea Level Change
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Tides, waves, currents
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Tides are controlled by:
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the moon
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Two types of wave erosion are
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hydraulic action
abrasion-carries sediment |
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A strip of land that juts out from the coastline
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Headland
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Think bulges of rock a short distance from coastline
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Sea Stacks
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Seismic waves are caused by
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Earthquakes
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Seismic waves are also called
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tsunamis
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Chemical Weathering of underground rock create what?
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caverns
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Snow--->Ice--->Firn---->_________
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Glacier
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Glaciers are made of
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ice and firn that lies entirely or somewhat on mainland
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Ice Sheets
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huge, continent sized. Examples: Antartica, Greenland
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The snow on top of a mountain is called
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Ice cap
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small mountain glaciers, found at all latitudes
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Alpine Glaciers
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Glaciers form above what?
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the annual snowline
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Zone of Ablation
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net loss of the glacial budget; from melting, sublimation, wind
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Zone of Accumulation
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annual gain of the glacial budget; from snow, condensation, frost
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Equilibrium Line
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separates the two zones
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Glaciers erode the surface when they move; mountainous formations it can create are
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horn, aretes, tarn lake, cirque
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A glacial trough in a valley leaves
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hanging valley
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glacial debris deposited directly by the glacier
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till
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Four types of moraines, mountain glaciers
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ground, lateral, medial, terminal
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Glacier melts----->debris is left
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till, moraine, kettles, drumlins, esker, outwash plain
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Parts of the glacier ripping off into large body of water
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calving
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icebergs are produced by
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calving
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Glaciers are developed by
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snow into ice into firn into glacier
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Two zones the glacial budget balances
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zone of ablation, zone of accumulation
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Positive Mass Budget; net profit
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Zone of Accumulation
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Negative Mass Budget; net loss
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Zone of Ablation
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Ablation Versus Accumulation
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Ablation
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Three ways glacial erosion modifies landscapes
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plucking and quarrying; abrasion; crushing
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Glacial Erosion: Plucking and Quarrying
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ice frozen to glacier can remove rock
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Glacial Erosion: abrasion
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ice grinds on bedrock, polishing the rock
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Glacial Erosion: Crushing
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rocks are crushed by weight of glacier
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glaciers transports with them different rocks and sediments. how
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carried on glacier, frozen in ice, dragged along the bed
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Glacial Flour
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fine sediment carried by meltwater from base of glacier
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Glacial Deposits
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Drift
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Glaciofluvial deposition
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sorted by water deposition, meltwater streams; glacial outwash
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Glacial Period is also called
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Ice Age
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Long term periods of glacial ice
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glacial period
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shortterm period of glacial ice
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interglacial period
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Ice sheet that covered the Hudson Bay, created Great Lakes
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Laurentide Ice Sheet
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Sea water has contains what oxygen isotopes
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16o and 18o
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Warm water has more _____ isotopes
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16o
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Cold water has more ________ isotopes
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18o
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Oxygen Isotope Ratio
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isotopic ratio of marine skeletons; helped further understanding of glacial periods in cycles
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Glacial Theory popularized by
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Aggassiz
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Glacial Theory
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glaciers as mechanisms to move large boulders outside stream channels
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Oxygen Isotope Ratios popularized by
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Emiliani
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Astronomical Theory popularized by
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Milankovich
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Three Theories for Climatic Change
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Internal Energy, External Energy, Astronomical Theory
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Internal Energy Evidence for Climatic Changes
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landmass over polar region can cool surrounding ocean; increased mountain ranges mean more land at higher altitude
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External Energy Evidence for Climatic Changes
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variations of energy put out by sun, atmospheric changes
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Three atmospheric changes for climatic change
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dust particles filter solar energy; volcanic particles deflect the energy; carbon dioxide accumulation due to greenhouse effect
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Astronomical Theory
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physical change in Earth-Sun relationship
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Evidence for Astronomical Theory
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eccentricity in orbit due to other planets changing ours; til of earth changes
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For an ice age to occur based on the astronomical theory, what needs to occur
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elongated orbit, winter solstice is furthest from sun
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The more tilt the earth has
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the more exaggerated seasons
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Evidence for past glaciations: terrestial
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drift has left sediment, position of coastline, plant and animal fossils, ice cores
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Evidence for past glaciations: marine
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changes in distribution of marine fauna; oxygen isotope ratio--->alternating warm and cold cycles
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Three ways humans have effected global warming
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carbon dioxide is created greenhouse effect; industrial revolution, burning of fossil fuels,
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The urban heat island effect
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buildings make the days and nights warmer
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Ozone depletion caused by
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CFCs (fridges, styrofoam), ozone holes over polar regions, industrial revolution----->carbon
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can melt oceanic rock
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magma
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igneous rock formed from magma
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basalt
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Cinder Cone
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small volcano, comes from basaltic rock, violent eruption out of single vent
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Fault Block Mountains
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tensional fault, cracks and breaks apart
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Earthquake focus
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place of origin in ocean
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Epicenter
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point on Earths surface directly above focus
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Volcanic Activity at Continent/Oceanic convergent plates
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coastal mountains, violent eruptions, composite volcanos
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Volcanic Activity at Oceanic/Oceanic convergent plates
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island arcs (Phillippines)
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Volcanic Activity within a plate
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non violent eruption; hotspots; shield volcanos--->Hawaii
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Interplate Earthquakes
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happen because of isostatic rebound
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Weathering is
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changing material
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Earthflow, mudflow
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rocks and soil moving downslope with water; slow, stumping
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Jointing suggests
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different rocks weather faster then others
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Mechanical Weathering
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physical breakdown of rock
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Frost Wedging
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due to freeze and thaw of water
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Salt Wedging
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due to growth of salt particles; salt expands--->breaks rock
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Exfoliation causes rocks to
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peel and lose a layel
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Cracking in rocks due to
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change of pressure
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Biological Activity in Mechanical weathering of rocks
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by tree roots
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Mass wasting
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weathering through movement
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Velocity of water is determined by
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gradient, volume, turbulence
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Meandering Stream
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stream that forks and causes valley widening
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Cutoff Meanders and Oxbow Lakes are examples of
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meandering streams
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Braided Streams are networks of channels separated by what
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bars
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Braided streams are caused by
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easily eroded banks, large sediment flow, large variation in discharge
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Constant, year-round stream
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Perennial
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Intermittent stream
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Ephemeral
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Graded Stream
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stream in equilibrium, gradient is smooth
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Valley Deepening
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rapid velocity or large flow will take place
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Valley Widening
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energy diminishes and stream erodes laterally, then meanders
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Valley Lengthening
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Headward Erosion, Delta Formation
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Drainage Basins
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drainage into closed basins
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