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52 Cards in this Set
- Front
- Back
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What is the definition of a glacier?
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a thick ice mass that originates on land from the accumulation, compaction, and recrystallization of snow. Glacial ice flows.
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Where do glaciers form?
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Mountain glacier-high altitudes, Continental glaciers-high latitudes
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What is the difference between a mountain and a continental glacier?
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Mountain/Alpine/Valley-smaller then ice sheets, lengths greater then widths, cover small region
Continental/Ice Sheets-cover large regions(10% Earth) |
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How do glaciers move?
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Internal-plastic flow-flowing solid-200 m/yr (rotation of grains, internal slipping, melt&refreeze
External-basal slip-slipping on a layer of water between ice and bedrock- 200 m/yr |
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Where within a mountain glacier is the movement fastest?
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In the middle away from the friction of the sides and bottom
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Describe the glacial budget.
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IN-Zone of accumulation-snow accumulates
OUT-Zone of ablation-general term for loss of ice. (melting or calving) |
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How do glaciers loss mass?
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Ablation
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Describe the types and locations of glacial sediment.
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Till-material deposited directly by the glacier. (unsorted debris transported by glaciers and deposited on land.)
Sorted Sediments-material laid down by glacial melt water. |
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Moraines
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pile of debris that has been transported and deposited by glacier
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Eskers
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Ridge of sorted sand and gravel deposited in sub-glacial melt water tunnels.
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Kettle lakes
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A water filled depression left by a glacial block (form on moraines)
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Erratics
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boulders, transported by glaciers and left on the surface as a glacier melted
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Drumlins
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elongate hills formed when a glacier overrides glacial till
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Outwash plains
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sand and gravel deposited by glacial melt water. (sorted material)
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Horns
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a pyramid-like peak formed by glacial action in three or more cirques surrounding the mountain summit.
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Arêtes
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a narrow, knife-like ridge separating two adjacent glacial valleys
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Hanging valleys
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a tributary that enters a glacial trough high above the floor of the trough-little water falss going into where main glacier was melted.
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Truncated spurs
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eroded triangular shaped cliffs in glaciated valleys.
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Tarn lakes
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tiny lakes in cirques when glaciers melt
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Cirques
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an amphitheater-shaped basin at the head of a glacial valley.
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U-Shaped Valleys
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Glacial Troughs
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How do glaciers effect the landscape?
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Ice sheets/Continental-subdue the landscape
Alpine/Mountain/Valley-accentuate the landscape |
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What are the stages of glaciation in Illinois?
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Wisconsinan- 75,000-10,000 ya
Illinoian- 300,000-125,000 ya Pre-Illinoian- 700,000-1.8 million ya |
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In general, when did glaciation occur in Illinois?
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18 million through 10,000 ya
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What direction did the glaciers advance from?
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North
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What is the Milakovitch theory?
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1. Changes in Earth’s tilt- 41,000 years
2. Procession of the Equinoxes- 22,000 years 3. Eccentricity- 100,000 years |
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What are the layers of the atmosphere?
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Thermosphere, Mesosphere, Stratosphere, Toposphere
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In which layer does weather occur?
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Troposphere
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What are the constituents of the ancient atmosphere?
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Methane, Ammonia, Water Vapor, Hydrogen
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What are the constituents of the present atmosphere?
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Nitrogen, Oxygen, Argon, Carbon Dioxide
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What are the global atmospheric circulation cells called, where are they located, and what do they do?
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Transfer moisture to higher latitudes
Hadley Cell-0-30 degrees latitude Ferrel Cell- 30-60 degrees latitude Polar Cell-60-90 degrees latitude |
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What is acid rain and how does it form?
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Results from chemical reaction between water and certain chemicals in the atmosphere.
Sulfur Oxide and Nitrogen Oxide |
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Describe the troposphere.
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Lowest layer-0-15km, contains 80% of the mass of the atmosphere, layer where weather occurs, temperature decreases with height.
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Describe the stratosphere.
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Occurs between 15-50km, contains 18% of mass of atmosphere, temperature increases with height, contains Ozone (O3) that shields the surface from UV radiation and solar radiation.
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What is O-zone and where does it occur?
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In the stratosphere, shields the surface from UV radiation
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Describe the green house effect.
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Suns short waves hit the ground, long wavelengths radiated to atmosphere and warm air rises and heats the greenhouse. Infrared rays radiate from ground and cannot pass through the glass.
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What are some of the green house gases?
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Carbon Dioxide, Methane, Water Vapor
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What drives surface currents?
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Atmospheric Circulation
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What is longshore transport?
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*** Movement of material along a beach. When the wave breaks at an angle on the beach, pebbles are carried up the shore and then when the wave draws back it brings pebbles back with it.
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What landforms are associated with wave refraction?
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Waves bend as they approach surface. Sea arches and Sea stacks
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What are the parts of a wave?
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Crest, trough, wavelength
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What causes a wave to break?
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When the depth to the ocean floor is ½ the wavelength. Wave trips over itself
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Does a wave move water or energy?
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Moves energy
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What causes tides?
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Gravitational influence of the Moon and Sun
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What is a spring tide?
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When the moon, earth, and sun are aligned, the pull of the moon and sun are combined. At these times, the high tides are very high and the low tides are very low. This is known as a spring high tide. Spring tides are especially strong tides (they do not have anything to do with the season Spring). The gravitational forces of the Moon and the Sun both contribute to the tides.
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What is a neap tide?
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When the sun and moon work at right angles the bulges of ocean water cancel each other. The result is a smaller difference between high and low tides and is known as a neap tide. Neap tides are especially weak tides. They occur when the gravitational forces of the Moon and the Sun are perpendicular to one another (with respect to the Earth).
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What drives thermohaline (deep sea) currents?
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Density Differences
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What effect does this current have on our climate?
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Warm water = salty = weighs less then cold.
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What defines a desert?
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Less then 250mm of precipitation, lacking vegetation, cannot support large population
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Where do each of the desert types occur?
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Subtropical-Centered around 30 degrees North and South latitude, Geographically extensive
Continental Interior-Far from sources of moisture(oceans) Rainshadow-Mountain ranges Costal-Cool dry air blows in from ocean Polar-Cold air holds very little moisture. Cold climates-Rain freezes to ice |
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How is each desert type formed?
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***
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What are the types of sand dunes and under what conditions does each form?
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Limited Amounts of Sand:
Barchan=sand is limited, wind is in one direction. Longitudinal/Linear=sand is limited, wind is converging. Star=sand scarce, wind varies direction Abundance of Sand: Transverse=lot of sand, moderate wind Parabolic=lot of sand, strong offshore wind(parabolic)(beach). |
