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