Geography Final Exam
3 Crustal Orders of Relief
1. Continental Landmassesand Ocean Basins 2. Major Continental and Ocean Landforms 3. Genetic Landform Features
6 Major Factors Influencing Geomorphology
1. Geology 2. Topography 3. Chronological 4. Climate 5. Biological (organic activity) 6. Abiotic Processes (water, wind, ice, gravity) *** Human Factor
2 Hypothesizes for desert pavement
1. deflation blows away loose or non cohesive sediment, eroding fine dust and sand leaving behind a compacted concentration of pebbles and gravel 2. windblown particles settle between and below coarse rocks and pebbles, rain washes the dust downward creating the pavement
Sediments are moved by... (4 processes)
1. solution 2. suspension 3. saltation 4. traction
Slide types
2 forms: translational & rotational
Continental Glaciers
3 type: Ice sheets, ice caps, ice fields; the largest type of glaciers
Slopes
A curved, inclined surface that bounds a landform (also known as a hillslope)
Dune
A depositional feature of sand grains deposited in mounds, ridges, and hills
Landform
A distinct geographic feature
Joints
A fracture or separation in rock that occurs without displacement of the sides; increases the surface area of the rock exposed to the weathering process
Glacier mass balance
A glacier is in equilibrium when the accumulation and ablation of snow is equal
Karst Topography
A landscape formed from the dissolution of soluble rocks such as limestone; poorly developed surface drainage and features that appear bumpy and pitted
Base Level
A level below which a stream cannot erode away anymore and thus the lowest operative level for denudation processes
Cave
A natural underground area large enough for humans to enter; generally form just below the water table
Stream Discharge
A stream's volume of flow per unit of time; channel width X channel depth X stream velocity
Yardangs
A streamline rock structure formed by deflation and abrasion; appears elongated and aligned with the most effective wind direction
Landslide
A sudden rapid movement of a cohesive mass of soil, regolith, or bedrock; a large amount of material falls simultaneously
Q: Particles that are dragged, pushed, or rolled along the bottom of a stream comprise the stream's: A. Bed Load B. Suspended load C. Dissolved load D. Braided load
A. Bed load
Q: Watersheds are defined by: A. Drainage Divides B. Stream Orders C. Fluvial Units D. Continental Divides
A. Drainage Divides
Q: Most of the sandy regions of the world are located: A. near sub-tropical high pressure B. Near ITCZ C. In the western hemisphere
A. Near sub-tropical high pressure
Q: The level below which a stream cannot erode its valley is... A. Base level B. Slope C. Deposition D. Drainage density E. Drainage rank
A. base level
Which of the following is incorrectly matched? A. point bar - area of erosion B. Braided stream - maze of interconnected channels C. Aggradation - sediment accumulation in the stream channel D. Cutback - outer portion of meander stream
A. point bar is not an area of erosion; it is an area of deposition
Drainage Patterns
An arrangement of channels in an area; defined by variations in rock resistance, climate, and hydrology (7 main types)
Outwash Plain
Area of glacial stream deposits of stratified drift with meltwater-fed, braided, and overloaded steams; occurs beyond a glacier's morainal deposits
Parallel Drainage
Associated with steep slopes
Q: If the load exceeds a stream's capacity, sediment accumulates in the bed in a process called: A. Downcutting B. Aggradation C. Degradation D. Saltation
B. Aggradation
Q: Elongated, streamlined ridges aligned parallel to the most effective wind directions are called: A. Desert Pavements B. Yardangs C. Ventifacts D. Alluvial rock structures
B. yardangs
Q: A crescent-shaped dune with horns pointed downwind is a: A. parabolic B. barchan C. transverse D. longitudinal E. star
B.Barchan
Physical Weathering (Mechanical Weathering) *3 main types
Breaking up rock without any chemical alteration; produces more surface area! (occurs primarily by: frost wedging, salt-crystal growth, & exfoliation)
Q: Desert pavement is formed by the process of: A. Abrasion B. Stream erosion C. Deflation D. Stream deposition E. Saltation
C. Deflation
Q: A wind-sculpted accumulation of sand is a: A. Yardang B. blowout depression C. Dune D. Desert pavement
C. Dune
Q: For purposes of discussing eolian processes, wind acts like a: A. Gas B. solid C. Fluid D. Plasma
C. Fluid
Meandering Stream
Channel slope is gradual, stream develop a sinuous (snakelike) form, weaving back and forth across the landscape; the portion of the stream flowing at maximum velocity moves diagonally across the stream from bend to bend
Salt-Crystal Growth/Salt Wedging
Crystals in rock grow and enlarge overtime by cryallization and force apart mineral grains and break up the rock (common in the Southwest with shale and sandstone)
Q: A drainage basin is defined by: A. Proximity to coast B. Salinity of the stream water C. steepness of the stream bed D. its drainage divides
D. Drainage divides
Q: Why is glacial ice analogous to metamorphic rock? A. it has a crystalline structure B. it is a solid C. it has a definite chemical composition D. it forms as a result of recrystallization caused by pressure
D. it forms as a result of recrystallization caused by pressure
Q: As the discharge of a stream increases, which of the following also happens? A. The rate of flow decreases B. Channel width increases but channel depth decreases C. stream channels narrow, become shallower and lose velocity D. width, depth and velocity all increase
D. width, depth, and velocity all increase
Q: With no clear geometry and no true stream valley, this drainage pattern occurs in area such as glaciated shield regions:
Deranged
Q: A landform created by erosion on the outside of a bend in a meandering stream channel is a: A. Point bar B. Mid-channel bar C. Oxbow lake D. Suspended load E. Cut bank
E. Cut bank
Topography
Elevation and relief of the Earth's surface
Relief
Elevation differences in a local landscape
Eolian/Aeolian
Eroded, transported, or deposited material by the wind; air is a fluid and has similar properties to water
Q: The upper portion of a glacier flows ____ the lower portion of the glacier. A. Faster than B. slower than C. At the same speed as
Fast than
Sediment
Fine-grated mineral matter that is transported and deposited by air, water, or ice
Floodplain
Flat, low-lying area adjacent to a channel and subjected to recurrent flooding; area that is inundated when the river overflows its channel during times of high flow; as the water recedes, it leaves behind alluvial deposits that mask the underlying rock
Hydraulic Action
Fluvial erosion in which flowing water alone loosens and lifts rocks
Fluvial Abrasion
Fluvial erosion in which rock and sediment grinding and carving the stream bed like liquid sandpaper
Frost Wedging/Frost Action
Freeze-thaw cycle that can overcome the tensional strength of rock and eventually breaks the rock apart (Important in humid continental and subarctic [humid mircothermal], & polar climates)
Alpine Glaciers
Glacier in a mountain range; 3 Types: Cirque, Valley & Piedmont
Karst Springs
Groundwater emerged as pool or stream
Q: Which of the following is not a mechanical weathering process? A. Salt crystal growth B. Hydrolysis C. Frost Wedging D. Exfoliation
Hydrolysis
Q: In terms of areal extent, order the types of glaciers from largest to smallest.
Ice sheet, Ice cap, ice field, alpine glacier
Columnar Jointing
Igneous rocks cool and develop shrinkage joints along pillar-like columns
Column/Pillar
Joined stalactites/stalagmites
Oxbow Lake
Lake that was part of the channel of a meandering stream, isolated when a stream eroded its outer bank, forming a cut off through the neck of the looping meander; may become part if the river again when it floods
Dissolved Load
Material that travels in a chemical solution in a stream derived from minerals such as limestone
Ice Cap
Mini Ice sheet that is roughly circular
Q: Exfoliation occurs because:
Overlying rock is removed, thereby allowing underlying rock mass to expand and fracture
Soil Creep
Persistent, gradual mass movement of surface soil; dry and slow; caused by freeze-thaw action of the soil
Weathering
Physical or chemical breakdown of rocks
Kettle
Post-glacial depressions or lakes
Exfoliation (Sheeting)
Process whereby rock peels or slips off in sheets instead of breaking up into grains; exfoliation domes are probably the largest weathering features on Earth (most active in igneous rocks, Yosemite)
Fluvial
Processes that are related expressly to streams and rivers
Erosion
Removal or transportation of weathered material by water, wind, ice, or gravity
Bedrock
Rock below the soil that is basically unweathered *Parent rock from which weathered regolith and soil develops
Q: The weathering of limestone can create circular depressions known as:
Sinkholes
Rotational Slide
Surface material moves along a concave surface, rotates
Competence of a stream
The ability of a stream to move particles of a specific size and is a function of the stream velocity and the energy available to move materials
Chemical Weathering *4 main types
The chemical breakdown, in the presence of water, of the constituent minerals in rock (hydration, hydrolysis, oxidation, carbonation)
Mass Movement/Mass Wasting
The downslope movement of a body of material made up of soil, sediment, or rock propelled by the force of gravity
Differential weathering
The effect of different resistances in rock, coupled with variations in the intensity of physical and chemical weathering
Delta
The level, or nearly level depositional plain formed where a river enters a lake or ocean
Drainage Basin
The portion of landscape from which river systems receive their water
Deposition
The process by which weathered and eroded materials are laid down or placed in a location that is different from their source
Regolith
The rock overlying the bedrock that undergoes continual weathering * Is the basis for soil development
Traction
The rolling or dragging of materials along the streamed
Geomorphology
The study of the formation, shape, spatial distribution and evolution of landforms on Earth
Ultimate vs Local Base level
Ultimate = sea level; local = cannot go any lower but isn't as low as sea level, can be artificial (like a dam)
Carbonation
Water vapor dissolves carbon dioxide creating rain with carbonic acid, then the acid can dissolve minerals containing calcium, magnesium, potassium, or sodium
Oxidation
When certain metallic elements combine with oxygen to form oxides; the most common form is "rusting" of iron
Sediment Transport
When stream energy is high and supply of sediment is present, streamflow propels sand, pebbles, and gravel downstream
Aggradation
When the load exceeds a stream's capacity and sediment accumulates in the stream bed building up the channel through deposition
Cirque Glacier
a glacier that forms within the snow filling a bowl-shaped recess at the head of a valley
Firn
a granular, partly compacted snow that is intermediate between snow and ice
Desert Pavement
a hard, stony surface that commonly occurs in arid regions; in general, these surfaces are fragile and protect underlying sediment from further deflation and erosion
Cavern
a large cave formed by chemical processes
Multiple-Thread Stream Channels: Braided Stream
a stream with excess sediment becomes a maze of interconnected channels; often occur when reduced discharge lower a stream's transporting ability; commonly occur in glacial environments
Point bar
accumulation of sediment on the inside of the curve due to the slowest water velocity
Till plain
also called a ground moraine; deposition of till the formed behind a terminal moraine as the glacier retreats; composed of coarse till with low and rolling relief, and a deranged drainage pattern
Ice sheet
an extensive, continuous mass of ice that may occur on a continental scale; common in Antarctica and Greenland; biggest type of continental glaciers
Denudation
any process that wears away or rearranges landforms; processes include: weathering, mass movement, erosion, and deposition
Drainage Divides
boundaries of drainage basins
Trellis Drainage
characteristics of dipping/folded topography; drainage is influenced by rock structures that vary in resistance to erosion
Sinkholes
circular depressions in the ground surface; can trigger a collapse
Bed Load
course materials that are dragged along the bed of a stream by traction or saltation because the particles are too large to remain in suspension
Barchan dune structure
crescent shaped with horns pointed downwind; found in areas with constant winds, little directional variability, where limited sand is available
Parabolic dune structure
crescent shaped with opening end facing up-wind; U-shaped blowout and arms anchored by vegetation
Hydrolysis
decomposition of a chemical compound by reaction with water; produces a new mineral through the chemical process (unlike hydration)
Dripstones
deposit formed from dripping solution and precipitates
Till
direct ice deposits that appear unstratified and unsorted; a specific form of glacial drift
Rectangular Drainage
dune formed by a faulted and jointed landscape with directs stream courses in patterns of right angles
Ice field
elongated pattern over a mountainous region and is not large enough to from the dome of an ice cap; can be found in South America
Deflation
erosion of the ground surface from the lifting and removal of individual particles
Cutbank (undercut bank)
erosive action from the outer portion of the curve being subject to the fastest water velocity
Suspended Load
fine particles held in suspension in a stream and the particles are not deposited until the stream velocity hits zero
Permafrost
frozen ground
Alluvium
general term for clay, silt, sand, gravel, and other mineral fragments transported by running water
Stalactites
grow from the ceiling downward
Stalagmites
grow from the ground up
Mudflow
high moisture content, fast; can pick up more debris as it moves
Drumlin
hills of deposited till that are streamlined in the direction of ice sheet movement
Alluvial Fan
in arid, and semiarid climates, cone-shaped deposits of fluvial sediments; produced when flowing water abruptly loses velocity as it leaves the constricted channel of a canyon and drops layer upon layer of sediment along the base of the mountain block
Glaciers
large mass of recrystallized, perennial ice, resting on land, or extending shelf-like over the land into the sea
Loess
large quantities of fine-grained clays and silts blown by the wind great distances and redeposited as a generally unstratified homogeneous blanket of material covering existing landscapes; the soils derived from loess are the basis for some of Earth's "breadbasket" farming regions
Lateral Moraines
lengthy ridges of till along each side of a glacier in areas that have undergone alpine glaciations
Alluvial Terraces
level areas that appear as topographic steps above a stream, created by the stream as it scours with renewed downcutting into its floodplain; rejuvenation
Longitudinal dune structure
linear, slightly sinuous, ridge-shaped; aligned parallel with the wind direction
Natural Levees
low ridges of course sediment that forms on either sides of a river formed by flooding
Moraine
marginal glacial deposits of unsorted and unstratified material; mark glacial retreat
Debris Avalanche
mass of falling and tumbling rock, debris, and soil traveling at a high velocity owing to the presence of ice and water the fluidize the debris
Valley Glaciers
masses of ice confined within a valley that originally was formed by a stream action
Sediment Load
material carried by the stream; increased discharge moves a greater amount of sediment
Translational slide
movement along a flat surface roughly parallel to the angle of the slope
Deranged Drainage
no clear geometry
Annular Drainage
occur on structural domes with concentric patterns of rock strata guiding steam courses
Star dune structure
pyramidal-snapped, 3 or more sinuous arms extending outward from a central peak resulting from effective winds shifting in all directions
Ventifacts
rocks that are pitted, grooved, or polished from eolian erosion
Graded Stream
stream in which the channel slope has adjusted so that stream velocity is just enough to transport the sediment load
Glacial Drift
the general term for all glacial deposits, both unsorted (till) and sorted (stratified drift)
Abrasion
the grinding and shaping or rock surfaces by the "sandblasting" action of the particles captured in the air
Ablation
the processes that cause losses to the glaciers mass
Saltation
the way particles may bounce along in short hops and jumps; these particles are too large to remain in suspension but are not confined to traction
A dune cross section includes:
the windward slope, the leeward slope, slip faces
Capacity of a Stream
total possible sediment load that it can transport and is a function of discharge
Dendritic Drainage
tree-like pattern
The wind has to reach a particular _____ in order to move particles of a certain size.
velocity; the bigger the particle, the stronger the wind must be to move the particle
Rockfall
volume of rock that falls through the air and hits a surface; dry and fast
Weather influencing weathering processes
wet, warm = speed up chemical weathering processes; cold = freeze-thaw cycles that cause physical weathering
Degradation
when sediment is eroded along a stream causing channel incision
Radial Drainage
when streams flow off a central peak or dome (ex: volcanic mountains)
Nickpoints
when the longitudinal profile of a stream contains an abrupt change in gradient, such as a waterfall or an area of rapids
Medial Moraines
when two glaciers with lateral moraines form
Hydration
where water becomes part of the mineral; involves little chemical change but a change in the structure; rocks that undergo this often expand creating a mechanical wedging effect on the rock
Piedmont Glacier
wherever several valley glaciers pour out of their confining valleys
Any variation or bump in a longitudinal profile of a stream will....
will be smoothed out over time as the stream adjusts toward a graded condition
