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GEOLOGY 102
FINAL EXAM
74
Geology
Undergraduate 1
04/29/2007

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Cards

Term
What is the definition of a glacier?
Definition
a thick ice mass that originates on land from the accumulation, compaction, and recrystallization of snow
Term
Where do glaciers form?
Definition
Valley (Alpine), Ice Sheets (Continental glacier)
Term
What is the difference between a mountain and a continental glacier?
Definition
Mountain glaciers are smaller then the Continental and only cover small region.
Continental occurs at high latitudes, while mountain glaciers occur at high altitudes.
Term
How do glaciers move?
Definition
Plastic Flow - flowing solid
(internal movement)
Basal Slip - movement over bedrock (external pressure melts ice)
Term
Where within a mountain glacier is the movement fastest?
Definition
Center (Top to Bottom!, least resistance)
Term
Describe the glacial budget
Definition
In = zone of accumulation (snow)
Out = Ablation, general term for loss of ice or snow from a glacier

In > Out = glacier will grow
Out > In = glacier will shrink
Term
How do glaciers lose mass?
Definition
If Out > In (Glacial Budget)
Ice out can be from melting or parts breaking off
Term
Till
Definition
Unsorted debris transported by glaciers and deposited on land. Mixture of unsorted mud, sand, pebbles, and larger rocks deposited by glaciers. material deposited directly by the glacier
Term
Moraines
Definition
a pile of debris that has been transported and deposited by a glacier
Term
Terminal Moraine
Definition
Debris pushed along in front of the glacier
Term
Ground Moraine
Definition
debris accumulated under the glacier
(unsorted)
Term
Drift
Definition
Sediment deposited on land or in water as a result of glaciation
Term
Erratics
Definition
boulders, transported by glaciers and left on the surface as the glacier melted
Term
Diamicton
Definition
A mixture of sediments of varying sizes. (Does not infer digenesis)
Term
Esker
Definition
ridge of sorted sand and gravel deposited in sub-glacial melt water tunnels. (sorted)
Term
Kettle lake
Definition
a water filled depression left by a glacial ice block.
Term
Outwash (plain)
Definition
sand and gravels deposited by glacial melt water. (sorted)
Term
Drumlin
Definition
elongate hills formed when a glacier overrides glacial till
Term
Sorted Sediments
Definition
material laid down by glacial melt water
Term
Hanging valley
Definition
a tributary that enters a glacial trough high above the floor of the trough.
Term
Arête
Definition
a narrow, knifelike ridge separating two adjacent glaciated valleys
Term
Tarn
Definition
a small lake in a cirque.
Term
Glacial trough
Definition
U-shaped glacial valley
Term
Truncated spurs
Definition
eroded triangular shaped cliffs in glaciated valleys.
Term
Cirque
Definition
an amphitheater-shaped basin at the head of a glaciated valley.
Term
Horn
Definition
a pyramid-like peak formed by glacial action in three or more cirques surrounding a mountain summit.
Term
What do Ice Sheets do to a landscape?
Definition
tend to subdue the landscape
Term
What do Valley Glaciers do to a landscape?
Definition
tend to accentuate the landscape
Term
What are the stages of glaciation in Illinois?
Definition
1. Wisconsin, 2. Illinoisan, 3. Pre-Illinoisan
Term
In general, when did glaciation occur in Illinois?
Definition
2 million until 10,000 years ago
Term
What direction did the glaciers advance from?
Definition
They moved from the North to the South.
Great Lakes and Canada to Mississippi and South from there
Term
What is the Milakovitch theory?
Definition
1- Eccentricity of the orbit: earth does not go around in a perfect circle, sometimes further away (colder), sometimes closer (hotter)
2- Change in Earth's tilt
3- Procession of the Equinoxes
(General idea: Astronomical events can influence the temperature of the earth)
Term
What are the layers of the atmosphere?
Definition
Troposphere, Stratosphere, Mesosphere, Thermosphere
Term
In which layer does weather occur?
Definition
Troposphere
Term
What are the constituents of the ancient atmosphere?
Definition
Methane, Ammonia, Water Vapor, Hydrogen (NO OXYGEN)
Term
What are the constituents of the present atmosphere?
Definition
Nitrogen, Oxygen, Argon, Carbon Dioxide
Term
Describe the troposphere.
Definition
lowest layer, contains 80% of the mass of the atmosphere, layer where weather occurs, temperature decreases with height
Term
Describe the stratosphere.
Definition
Occurs between 15-50 km above surface, contains 18% of the mass of the atmosphere, temperature increases with height, contains ozone (O3) that shields the surface from UV radiation
Term
Describe the green house effect.
Definition
incoming solar radiation consists of short, high energy waves. These waves pass thought the atmosphere and are absorbed by the Earth. Some of this absorbed energy is then released back into the atmosphere as long, low energy waves which are absorbed by the particles in the atmosphere and raise the temperature.
Term
What are some of the green house gases?
Definition
1.Water vapor
2.Carbon dioxide
3.methane
4.Chlo-floro-carbons (CFCs)
Term
What is acid rain and how does it form?
Definition
results from the chemical reaction between water and certain compounds in the atmosphere.
Carbon dioxide
Sulfur oxides (SOx)
Nitrogen oxides (NOx)
Term
What are the global atmospheric circulation cells called, where are they located, and what do they do?
Definition
1) Polar, Ferrel, Hadley
2) Pole, Middle, Equator, Equator, Middle, Pole
3) Cold dry air descends as warm moist air rises
Term
What drives surface currents?
Definition
wind
Term
What causes a wave to break?
Definition
when: wave base = 1/2 wave length as well as the resistance from the ocean floor as the wave travels toward the beach
Term
What causes tides?
Definition
Gravitational influence of the Moon and Sun (occurs twice daily)
Term
What drives thermohaline (deep sea) currents?
Definition
Driven by difference density (temperature and salinity)
Term
What is longshore transport?
Definition
Moving material down a beach. Waves hit the beach at an angle causing material to be thrown back at an angle, which is then pulled straight down
ex: /!/!/! /=push back at an angle, !=drawn back down in a straight line
Term
What landforms are associated with wave refraction?
Definition
Embayment (less energy), Headland (more energy, erode faster)
Term
Land forms associated with wave refraction
Definition
Sea Arches and Sea Stacks
Term
Wave refraction does what to a coastline?
Definition
Straightens it out (erodes it back into a straight line)
Term
What are the parts of a wave?
Definition
Trough (low part), Crest (high part)
Term
Does a wave move: water or energy?
Definition
energy
Term
What is a spring tide?
Definition
When the moon and sun are aligned, the high tide is exaggerated
Term
What is a neap tide?
Definition
When the sun and moon are perpendicular (they form a right angle), each gravitational pulls are counteracted by the other. The high tide is small
Term
What effect does this current have on our climate?
Definition
The current is the transfer of heat energy, which helps keep the temperature moderate
Term
What defines a desert?
Definition
•Less than 10 inches of precipitation.
•Generally lacking in vegetation.
•Cannot support a large population
Term
Where do Subtropical Deserts form?
Definition
By the Hadley cell (above and below the equator), controlled by air circulation, most common type of desert found
Term
Where do Continental Interior Deserts form?
Definition
Far from sources of moisture, clouds just can't make it
Term
Where do rainshadow deserts occur?
Definition
Backside of mountain ranges, as pressure rises water is squeezed out over the mountain and becomes a "cold sponge." Once elevation drops moisture is sucked up creating a desert.
Term
Where do Coastal Deserts form?
Definition
Cool dry air is blown in from the ocean and absorbs all the moisture from the first area of land it meets
Term
Where do polar deserts form?
Definition
cold air holds little moisture, what does precipitate that does fall remains as ice for 1000's of years
Term
Barchan Dunes
Definition
Sand supply is limited, steady wind from one direction. "Horned" appearance, points which way the wind is blowing
Term
Star Dunes
Definition
Wind direction varies and sand supply is limited
Term
Transverse Dunes
Definition
Abundant sand, wind from one direction, form perpendicular to wind direction. (Barchan but with lots of sand)
Term
Parabolic Dunes
Definition
Develop along shorelines from off shore winds (Beaches are blown outward, sand is caught in vegetation, like Barchan but horns points opposite of wind direction). sand is abundant.
Term
Linear dunes
Definition
limited sand supply, form parallel to the convergence of wind.
Term
The type of dune that develops is dependent on what two things?
Definition
1) Sand Supply
2) Wind velocity and directional variability
Term
Describe the three ways a Basil Slip can happen
Definition
1) the fern (round pieces of ice) roll forward
2) Slippage between layers
3) Melting during the day, freezing at night
Term
Which gravitation pull is stronger on the Earth?
Definition
the moon's pull is stronger than the sun's pull
Term
types of glacial sediments
Definition
sorted (transported by water) and unsorted (by ice)
Term
How many tides are experienced every day on Earth?
Definition
2
Term
T/F: All rain is acidic
Definition
true, pure water is 7.0, normal rain is 5.2, and acid rain is between 3 and 4
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