1401 Geography, Test #4
Lava: AA, Pahoehoe
*AA-* flows more slowly and escaping gas breaks up the upper surface. The result is a very rugged and jagged surface, hence the name, which sounds like a barefoot Hawaiian walking over the sharp rock. *Pahoehoe-* lava that flows quickly and spreads out. When it cools, it has a relatively smooth surface.
Folding: Anticlines, Synclines, Monoclines
*Anticlines-* upward-arching folds *Synclines-* downward arching folds *Monoclines-* One half of a fold
Erosion of Headlands (Arches and Stacks)
*Arches-* if the waves break through a weak point in the headland this forms *Stacks-* as the arch continues to be eroded, the top finally falls leaving this form
Caprock: Mesa, Butte
*Caprock-* resistant rock *Mesa-* Flat top hill with caprock on top exists because everything around it eroded away *Butte-* very narrow mesa
Drainage Patterns: Dendritic, Radial, Centripetal, Trellised, Rectangular, Deranged
*Drainage Patterns-* the pattern a drainage network takes when viewed from the air *Dendritic-* tributaries look like branches on a tree. *Radial-* the streams flow away from a central point. *Centripetal-* Where there is interior drainage, the streams all converge on the playa *Trellised-* In areas with much folding, there will be short tributaries coming off of the ridges and larger streams in the troughs. *Rectangular-* Some rocks are fractured in a rectangular fashion and streams develop on the fractures. *Deranged-* In formerly glaciated regions, there may not have been time for an organized drainage pattern to develop and the streams can flow in many directions and there may be many lakes in the area
Faults: Normal, Reverse, Transform, Oblique
*Faults-* Rock moves along the break *Normal-* Side going up moves away from the other side. Two sides are being pulled from each other. *Reverse-* Two sides pushed agains each other causing one side to go up and down. *Transform-* The movement is horizontal *Oblique-*Movement both horizontal and vertical
Volcanoes Fissure, Shield, Cinder Cone, Composite
*Fissure-* Lava flows out the cracks of the surface *Shield-* free flowing lava spreads out over great distances and builds up a wide volcano with gentle slopes. *Cinder Cone-* Small pyroclastic eruptions *Composite-* Large continental volcanoes, pyroclastic eruptions
Principal Pedogenic Processes
*Podzolization-* is found in the coniferous forests of the humid mid-latitudes. There is plenty of rain and the soil is acidic, so there is heavy leaching in these areas which removes most of the mobile substances in the soil, leaving mostly silica in the A horizon. The water in the soil carries the leached material to the groundwater, where it is carried away. This process is common in the Eastern U.S. *Calcification-* is found in drier regions. In arid areas, there is not enough water to carry the leached material to groundwater. Instead, it accumulates in the B horizon. Calcium is common in desert areas because it is not washed away as it is in humid environments. Frequently in deserts calcium is leached down a short distance and accumulates, becoming a hard layer known as caliche (or, more officially, calcrete). *Salinization-* is common in desert soils with a high salt content. Salty water evaporates at the surface, leaving any salts in it behind. Occasionally, the land needs to be flushed with large amounts of water to remove the salts. *Laterization-* is common in tropical areas where there is very heavy rainfall. There is such intense leaching that most soil materials are removed, leaving a soil of mostly quartz sand and weathered iron and aluminum. In some instances, the iron, aluminum and quartz sand form a hard surface, known as laterite. Laterite frequently forms when the vegetation is removed.
Split, Barrier Beach
*Split-* is indentation in coast, sand grows out into water because of sand continuing to travel in the same direction and builds up *Barrier Beach-* drifting sand blocks cut off stream from ocean; when splits grows all the way across the indentation
Barrier Islands (Features & Development)
- narrow island parallel to mainland, they protect the mainland coasts from attack by storm waves; *Features-* islands have a beach on the seaward side, dunes in the middle, marsh on the mainland side, and lagoon between the island and the mainland *Development-* origin is not well understood; believed to of began as beaches or coastal dunes during the last ice age--when sea level was lower and beaches were found much further out than at present; as sea level rose, these beaches were left as islands when the land behind them became flooded
1. What coastal environmental conditions favor coastal erosion? What conditions favor coastal deposition? 2. By what processes do waves and currents erode coasts? Briefly describe each process? 3. Discuss the nature of hillslope failure processes as related to cohesive and non-cohesive materials slope materials.
1. Waterfalls, glaciers, deposition is precipitation and flocculation 2. Cavitation: intense erosion due to the surface collapse of air bubbles found in rapid flows of water Abrasion: occur from the particles held in the erosional mediums of wind and water. 3. Saturation of soil materials can reduce the cohesive bonds between individual soil particles resulting in the reduction of the internal strength of the hillslope
Midlatitude Broadleaf & Mixed Forest
A biome in moist continental climates in areas of warm-to-hot summers and cool-to-cold winters; relatively lush stands of broadleaf forests trend northward into needleleaf evergreen stands.
Emergent Coasts
A coast where the land is rising relative to sea level or sea level is falling relative to the land.
Warm Desert
A dry, often sandy region of little rainfall, extreme temperatures, and sparse vegetation.
Soil pH
A measure of the acidity of the soil
Soil
A mixture of mineral particles and organic material that covers the land, and in which terrestrial plants grow.
Glacier
A slow moving mass of ice formed by the accumulation and compaction of snow.
Vertical Zonation
A term applied to vegetation zones defined by altitude
Cold Desert
A type of desert where vegetation is sparse, winters are cold. summers are warm or hot, and precipitation is low.
Slump
A type of mass movement that occurs when a mass of material moves down a curved slope
Tropical Seasonal Forest & Scrub
A variable biome on the margins of the rain forests, occupying regions of lesser and more erratic rainfall; the site of transitional communities between the rain forests and tropical grasslands.
What is a volcano? Where and why do they form? Describe the five different types of volcanoes.
A volcano is generally a conical shaped hill or mountain built by accumulations of lava flows, tephra, and volcanic ash. Sixty percent of all active volcanoes occur at the boundaries between tectonic plates. 5 Types: - basalt plateau: least explosive, lava flows horizontal - shield: Some basaltic magmas can produce very large slightly sloping volcanoes, 6 to 12°, that have gently flowing magmas - Cinder Cone: small, made up of exploded rock blasted out of a central vent at a high velocity - Composite: made from alternate layers of lava flows and exploded rock - Caldera: most explosive, explosions leave depressions in earth
Paranormal Phenomena
Alleged abilities or events that fall outside the range of normal experience and established scientific explanations.
Tower Karst
An advanced stage of karst topography where most of the limestone has been dissolved, the landscape is dominated by tall, steep-sided conical hills of limestone.
Patterned Ground
Areas where freezing and thawing of the ground create polygonal forms of arranged rocks at the surface; can be circles, polygons, stripes, nets, and steps.
Swelling Clays
Certain types of clay swell when they get wet and contract when they dry
Continental Glacier
Continents covered in Ice (Antarctica and Greenland)
Transported Material
Eroded and deposited at its present location, it is weathered elsewhere.
Plateau
Extensive flat land raised above its surroundings
Alpine Glacier
Found in mountainous areas.
Needleleaf & Montane Forests
Further north into colder climates, needleleaf trees become more dominant, such as pine, spruce, and fir. Much of Canada an Siberia. In mountainous areas with climates a similar forest ecosystem is found. Often the small streams will be dry in the winder and larger ones are perennial, but ice covered during the winter.
Mediterranean Shrubland
Hot and dry summers, cool and moist winters. Plants resistant to fire and drought thrive.
Nuée Ardente
Incandescent volcanic debris buoyed up by hot gases that moves downslope in an avalanche fashion.
Volcanoes & Climate
Large volcanic eruptions inject sulphate aerosols into the troposphere and stratosphere, reducing the amount of solar radiation reaching the surface, resulting in a negative radiative forcing.
Rock Types Involved
Limestone is the most common rock type involved, but other rock types are also dissolved by water, like gypsum, dolomite and salt.
Describe the overall impact of extensive alpine glaciation on the mountainous regions of British Columbia. What are some of the more important erosional and depositional landforms?
Medial moraine down the center of the Salmon Glacier, British Columbia, Canada.
Dowsing
Method of divination whereby water or other underground resources are located by use forked stick.
Ice ages and sea level
Most sea level changes are due to changes in the amount of ice stored in glaciers. When glaciers get larger, there is less water for the oceans, so sea level drops. As glaciers get smaller, sea level rises.
Decomposers
Organisms that break down the dead remains of other organisms
Describe the common landforms found in periglacial regions.
Patterned Ground- ground showing a pattern of stones, fissures, and vegetation, typically forming polygons, rings, or stripes caused by repeated freezing and thawing. Palsas- a turf-covered mound, with a core of ice that rises above the surrounding bog or water surface. Pingos- a low hill or mound forced up by hydrostatic pressure in an area underlain by permafrost.
Outline the various processes of physical, chemical, or biological weathering.
Physical: breakdown of mineral or rock material by entirely mechanical methods brought about by a variety of causes. Chemical: involves the alteration of the chemical and mineralogical composition of the weathered material Biological: disintegration of rock and mineral due to the chemical and/or physical agents of an organism
Travertine Deposits
Strange shapes that develop in caverns after they get above the water table and erosion generally ceases.
Factors of Wave Size
Strength of the wind, how long it blows, and the distance over which they have had to develop (called fetch).
Dome
The center of the area is raised up and the surrounding land is deformed plastically
Temperate Rainforest
The cool, dense, rainy forests of the northern Pacific coast; enshrouded in fog much of the time; dominated by large conifers
Cause of Tides
The gravitational pull of the moon
Plucking
The weight and moving force of the glacier moving will erode the underneath bedrock and incorporate the fragments into the glacier.
Decreasing Slope Resistance
This can be done by removing the base of a slope, which is done by nature when streams undercut a hill and when waves undercut a cliff. People do this by putting in a road or house.
Residual Material
Unconsolidated and partly weathered mineral materials accumulated by disintegration of consolidated rock in place.
Biomes
a broad, regional type of ecosystem characterized by distinctive climate and soil conditions and a distinctive kind of biological community adapted to those conditions.
Tropical Rainforest
a broadleaf evergreen forest found in wet and hot regions near the equator.
Psuedoscience
a claim, belief or practice which is presented as scientific, but does not adhere to a valid scientific method, lacks supporting evidence or plausibility, cannot be reliably tested, or otherwise lacks scientific status.
Creation Science
a creationist attempt to refute the evidence of evolution
Eskers
a long, winding ridge or stream formed when sand and gravel fill meltwater tunnels beneath a glacier
Basin
a natural depression in the surface of the land often with a lake at the bottom of it
Gleization
a process of humus and clay accumulation in cold, wet climates with poor drainage
Soil Classification
a system to describe the characteristics of a given soil in terms of its derivation and physical makeup
Increasing Force
add weight in hillside; water in soil; buildings
Arrangement of Rock Layers
affects the stability of a slope. If the layers are parallel to the slope then the slope is weaker than if they are perpendicular.
Cirque
an amphitheater-shaped depression with an opening where the glacier flowed out. (erosion)
Drumlins
an oval or elongated hill believed to have been formed by the streamlined movement of glacial ice sheets across rock debris, or till.
Moraines
any glacially formed accumulation of unconsolidated glacial debris that occurs in both currently and formerly glaciated regions on Earth, through geomorphological processes.
Coral Reefs
are formed by accumulation of calcium carbonate from shells of corals and other critters; they require warm and shallow water (so found in tropical areas)
Grabens
areas of land that have dropped down between faults
Tropical Savanna
biome characterized by grasses and scattered trees, and herd animals such as zebras and antelopes
Submergent Coasts
caused by subsidence of land adjacent to the sea or a rise in sea level
Factors Affecting Soil Formation
climate, parent material, vegetation, topography, and time.
Periglacial
cold environments that are not continuously covered in ice.
Lahars
dangerous volcanic mudflows
Describe some of the landforms common to environments influenced by eolian processes.
deflation hollow, pans, sand dunes
Solution (Weathering)
dissolving of rocks or minerals by rainwater. This is a means of transportation as well as an erosion process.
Midlattitude Grasslands
dominated by grasses. Lack of water is the main reason for no trees in these regions found mostly in North America.
Slide
downslide movement along a flat surface; associated with rock layers
Texas Beaches
eroding coast (losing land) since mid 1800 because of decreased sand supply from the damming of rivers, and a rise in relative sea level---since last ice age has risen 120 meters, during same time it subsided 30 meters
Arctic and Alpine Tundra
extreme cold, low precipitation, short growing season, permafrost, perennials, dwarf shrubs
Solution Sinkholes
form when water dissolves the surface rock, creating a depression. The sinkhole slowly gets bigger over time
Collapse Sinkholes
form when water flowing underground erodes a cavity in the rock. As the cavity gets bigger, the overlying rock or soil will eventually fall in to the hole.
Sea Waves
formed due to continuous motion of water combined with the gravitational forces of the sun and the moon, and the blowing winds
Mass Balance
gains and loses of ice on glaciers.
Accumulation
gains ice mostly from snow, rain, and avalanches.
What factors often trigger mass movement?
gravitational force, weight of the material occurring at some point on the slope, angle of slope
Soil Horizons
horizontal layers that reveal a soil's history, characteristics, and usefulness
Ablation
ice lost by melting, sublimation, evaporation, and calving.
Wave Breaking
in shallow water, wave deforms because it's in contact with sea floor (to steep); water is slowed by friction and is greatest at the bottom of the wave while top is less affected therefore it travels faster
Kettles
is a shallow, sediment-filled body of water formed by retreating glaciers or draining floodwaters. The kettles are formed as a result of blocks of ice calving from glaciers and becoming submerged in the sediment on the outwash plain.
Winter Beaches
is the season of big, strong waves where sand is eroded off beach and deposited offshore--small, narrow beach and steep drop off under water
Summer Beaches
is the season of small, gentle waves where sand is pushed back onto beach--broad beach and gentle drop off under water
Erratics
large boulders that have been transported into an area by a glacier.
Batholith
large mass of intrusive igneous rock believed to have solidified deep within the earth
Sill
magma cooled horizontally
Dike
magma cooled vertically
Humus
material formed from decaying leaves and other organic matter
Flow
material moves as a viscous fluid
Safety Factor
measure of slope stability
Marine Terraces
old flat terraces that were below sea level that are exposed due to uplift
Neap Tides
one week after each spring tide---the moon and sun are at right angles and the lowest high tide occurs (in month of quarter moon)
What five factors are important in pedogenesis?
organisms, topography, time, parent material, and climate
Permafrost
permanently frozen ground.
Fall
pieces break off and fall down
Leaching
removal of dissolved materials from soil by water moving downwards
Cuestas
ridges are often asymmetrical
Scour
rocks carried on the bottom of the glacier wear away at the bedrock acting like a large piece of sandpaper.
Fiord Coasts
sea fills valleys that were carved by glaciers
Tides
sea level rising and falling along beaches twice a day
Littoral Drift
sediment that is transported through the combined processes of longshore drift and beach drift
Lysenkoism
strongly affected the agricultural and biological sciences in the SU with disastrous consequences
Describe some the important characteristics of soil.
texture, clay, soil ph, color, profiles
Cation Exchange Capacity
the ability of a particular soil to absorb and release cations
How does beach drift and longshore drift move sediment along coastlines?
the angle of the wave running along the surface, back wash, rip currents
Abrasion
the grinding away of rock by other rock particles carried in the glacier.
Texture
the look and feel of a rock's surface
Longshore Drift
the movement of material along a coast by waves that approach at an angle to the shore but recede directly away from it.
Rupture
the rock breaks
Elastic Deformation
the rock is compressed, but if the stress is removed, the rock will return to its original shape.
Plastic Deformation
the rock slowly flows to a new shape. Even if the stress stops, the rock will maintain its new shape.
Creep
the slow downhill movement of weathered rock material
Beach Drift
the transport of sediment in a zigzag pattern along a beach caused by the uprush of water from obliquely breaking waves
Subsidence of Coast
the weight of sediment deposited off shore can be enough to cause the surrounding land to subside which lowers the coast; sinking relative to sea level
Astrology
theory of the influence of planets and stars on human events
Scientific Heretics
those who challenge established scientific thought
Horn
three cirques meet, a peak is formed that is also jagged.
Horsts
two normal faults paralleling each other and if the rock in between rises
Tsunamis
underwater earthquakes, volcanoes, and landslides generate these waves; usually low height in the open water, but they rise up to 30 meters as they hit the coast; highly destructive
UFOs
unidentified flying objects
Wave Refraction
wave arriving to the coast at an angle because the wave doesn't touch the sea floor all at the same time so this results in the bending of waves
Describe the various processes that operate in periglacial regions.
weathering, ground ice, ice wedges, segregated ice, mass movement, erosion,
Hanging Valley
when the main valley has been widened and deepened by glacial erosion, leaving the side valley cut off abruptly from the main valley below.
Ria Coasts
where river valleys are frequently flooded, leaving indentations in the coastline
Spring Tides
where sun and moon align and make highest tides every two weeks---full and new moon
Arête
where to cirques meet, the ridge becomes jagged.