Geography Final
FIGURE 20-31 (LOCATION OF CORAL REEFS GLOBALLY)
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What are playas?
(salinas) interior bed where water flows into (playa lake) extremely flat
Sediment budget
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Japan 2011
11 March 9.0 magnitude along Pacific and Okhotsk plates (shook for 3 minutes) more than 15,000 fatalities 10 minute lead time on... **missing notes**
Describe Death Valley
140 miles, 4-16 miles wide 282 feet below sea level fault-block mountains mountains and wingless glass canyons (picture in notes)
The Pleistocene Glaciation
18 or 19 glacial periods 2.5 million ybp to 10,000 ybp ended within the Wisconsin (Würm) Glaciation max extent 1/3 of land covered in ice up to a few thousand meters thick ice sheets originated in subpolar & midlatitudes FIGURE 19.5
Sumatra 2014
26 December 9.2 magnitude earthquake along fault line between Indo-Australia and Burma Plates ocean floor rose 16ft 28 min later- 80ft wave makes landfall 60 miles from epicenter estimated 227 **missing some notes**
What is ephemeral stream?
99% of desert and streams (only flow when raining) a stream that carries water only during the "wet season" or during and immediately after rains
Name and describe the 4 types of sand dunes.
Barchan- most common migrate quickly take crescent shape Transverse- not as universe, associated with "ocean of sand" surface (only difference from Barchan) Seifs- long/narrow/ form in groups common in Australia Star Dunes- pyramid type build up-shaped like star
What is lateral erosion? (include cutbanks and point bar)
Begins as the stream sways from side to side; the main flow of the current swings from one bank to the other, eroding where the water speed is greatest and depositing where it is least. The water moves fastest on the outside of curves (cutbank) On the inside of a curve where water is moving slowly, alluvium is likely to accumulate, forming a point bar along the inside bank of the stream
What are the Theories of Landform Development?
Davis' Geomorphic Cycle, Penck's Theory of Crustal Change and Slope Development, Equilibrium Theory
Name and describe the three types of desert landscapes.
Ergs- large area covered with sand regs- tight covering of coarse gravel, pebbles, and/or boulders from which all sand and dust have been removed by wind and water. desert pavement, desert varnish (can age rocks) hamada- exposed/barren bedrock exposed by salt
Yellowstone National Park (geologic setting, hydrothermal conditions, geyser basins, mammoth hot springs)
Geologic Setting (highest concentration of hydrothermal features) Hydrothermal settings (2004-2010 caldera began to rise) Geyser basin- 5 major geyser basins, a half dozen minor ones, and an extensive scattering of individual or small groups of thermal features Mammoth Hot Springs- remarkable aggregation of hot-water terraces in the world. Here, groundwater percolates down from surrounding hills into thick layers of limestone.
What is headward erosion?
It is the basis of rill, gully, and valley formation and extension Erosion that cuts into the interfluve at the upper end of a gully or valley
What are the components of basin-and-range landforms (3)?
Ranges- (v shaped) Piedmont Zone- alluvial fans(fan shaped depositional feature of alluvium laid down by a stream issuing from a mountain canyon) bajadas (continuous of overlapping fans) basins- flat floor beyond the mountain front with a very gentle slope from all sides to some low point
Penck's Theory of Crystal Change and Slope Development
Walter Penck (German geomorphologist) stressed that uplift stimulates erosion immediately and that slope form is significantly influenced by the rate of uplift or other crustal deformation.
What is an exotic stream?
a stream that flows into a dry region, bringing its water from somewhere else. The water that feeds them comes from an adjacent wetter area or higher mountain area in the desert and has sufficient volume to survive passage across the dry lands. (the Nile River)
Fumaroles
a surface crack directly connected to a deep-seated heat source. (hot spring that lacks liquid water) is marked by steam issuing either continuously from a surface vent
Geysers
a temporary ejection in which hot water and steam is spout upward, then the geyser subsides into apparent inactivity until the next eruption. The basic principle activity involves the building up of pressure is relieved by an eruption.
What is glacial equilibrium?
a theoretical line separating the ablation zone and accumulation zone of a glacier along which accumulation exactly balances ablation
Describe Loess Dunes
a wind-deposited silt that is fine grained, calcareous, and usually buff colored
What is glacial accumulation?
addition of ice into a glacier by incorporation of snow zone-the upper portion of a glacier where there is a greater annual accumulation of ice than there is wastage.
Barrier Islands & Barrier Island Lagoons
always parallel to shoreline barrier island lagoons (tidal and mud flats)
Base Level
an imaginary surface extending underneath the continents from sea level at the coasts and indicating the lowest level to which land can be eroded
Describe the arches and natural bridges of Mesa-and-Scarp Terrain
arch- can form when the lower portions of a narrow "fin" of sedimentary rock weak and collapse, leaving an arch of more resistant rock above natural bridge- can form anytime the rock over which water flows changes from erosion-resistant to a less resistant type
Beaches and Beach Profiles
backshore only covered with water in storms foreshore @ high tide nearshore- waves break/surfing offshore- doesn't affect beaches build during quiet weather
Spits, Baymouth Bar, and Tombolo
build up to one long feature connected to land on only one side Baymouth Bar (becomes lagoon) Tombolo
What is the difference between capacity and competence?
capacity- to carry certain amount of sediment competence- steeper gradient = larger particles
Sinkholes and Groundwater Extraction
caused by human activity, for example Central Florida and massive limestone bedrock which leads to formation of sinkholes.
Erosion by Mountain Glaciers
cirques (grows as ice gets bigger and bigger) aretes and cols- break in spine that allows passage through horns glacial troughs (U shaped valley) glacial steps hanging glacial troughs (tributary trough to main trough)
Coastal Processes: lake vs. oceans
coast is the meeting of the lithosphere, atmosphere, hydrosphere winds are most important processes have more of an effect with larger bodies of water lakes= no tides, so no effect lake level and sea level fluctuations caused by different things coral reefs not in lakes
What are the two types of non-arid dunes?
coastal and loess
Name and describe the different Structural Relationships.
consequent streams- subsequent streams- antecedent streams- stream that predates the existence of the hill or mountain through which it flows superimposed stream- look photoshopped because don't match
How do glaciers form and what are the three zones?
crystalline snow (compacted into granular snow-continues and gets neve-air squeezed out and gets its blue color) Accumulation Zone Ablation Zone Equilibrium Zone
What is aeolian erosion?
deflatation-shifting of loose particles as a result of their being blown either through the air or along the ground abrasion- caused by wind driven dust ventifacts- rocks so faceted by such wind "sandblasting"
What are the different drainage patterns?
dendritic- most common trellis- like garden trellis radial- streams radiating outwards centripetal- streams flow in annular- most complex (ring-shaped pattern on dome)
What is the difference between dissolved load, suspended load, and bedload?
dissolved load- minerals(salts) are dissolved in the water and carried in solution suspended load- fine particles of clay and silt are carried in suspension, moving along with the water without ever touching the streambed bedload- sand,gravel, and larger rock fragments, the smaller particles are moved along the general streamflow in a series of jumps or bounces (saltation and traction)
What is glacial deposition?
driff- anything deposited by glacier till glaciofluvial deposition
Describe the erosion of Mesa-and-Scarp Terrain
erosion of escarpment edge (butte-erosional remnant having very small surface area and cliffs and pinnacle-smaller and further denudation)
Jetties
forcing the water to channel (deposition upstream) usually built in pairs on either side of a river or harbor entrance interfere with longshore currents in the same way as groins, trapping sand on the upcurrent side while causing erosion on the downcurrent side
What is a floodplain and what are examples?
frequent with meandering flow along a wide level valley floor (definition: a low-lying, nearly flat alluvial valley floor that is periodically inundated with floodwaters) cutoff meander natural levee yazoo stream
What are the three types of coral reefs?
fringing reefs barrier reefs atolls- east to spot (color)
What is glacial erosion?
glacial plucking glacial abrasion subglacial meltwater erosion
Describe desertification (including the Process)
growth of deserts has happened on almost every continent in last 100 years Process: poor land use drought sparse vegetation disappears soil exposed to erosion increased drought in these areas with changing climate could lose 26.5 million acres of ag land in a year
Describe Coastal Dunes.
has active winds in dune formation along many stretches of ocean and lake coasts, whether the climate is dry or not (ocean waves deposit sand along the beach)
Delta (formation)
helps to lengthen a stream, usually consist of a maze of roughly parallel channels called distributaries through which water flows slowly toward the sea. only one in US
Describe Mountain Glaciers.
highland icefields and nunatak(protruding pinnacles) valley glacier piedmont glacier alpine glacier cirque glacier
Wave Refraction
hits shoreline and changes direction
What are the different types of hydrothermal features?
hot springs, geysers, and fumaroles
Flow vs. Advance
ice always flowing but not necessarily advancing advancing means the outer edge is moving forward there is even flow when a glacier retreats
What is stream capture? (captor stream, beheaded stream, elbow of capture)
illustrated when a portion of the drainage basin of one stream is diverted into the basin of another stream by natural processes (relatively uncommon in nature) Stream A is called the captor stream and the upper part of Stream B is called the captured stream and lower is the beheaded stream The abrupt bend in the stream channel where the capture took place in the elbow of capture
Describe the impact of the melting of Antarctica
impacts all aspects of the world environment ice shelves are disintegrating along peninsula loss primarily due to warmer currents melting from below (mostly in western part)
Describe badlands of Mesa-and-Scarp Terrian
intricately rilled and barren terrain of arid and semiarid regions, characterized by a multiplicity of short, steep slopes. Utah Bryce Canyon?
Groins
is a short wall or dam built out from a beach to impede the longshore current and force sand deposition on the upcurrent side of the structure
What is karst topography? (4 types)
karst derives from Kras Plateau region of Slovenia, a rugged hilly part area that has been shaped almost entirely by solution action in limestone formation (sinkholes, sinkholes and groundwater extractions, surface drainage, and tower karst)
Name several characteristics of tsunamis
long wavelength (125 ft) abrupt movement on ocean floor can travel upward 435 mph, slows near coast can get 130 ft water retreats from coast prior to landfall then get a surge of water because of connection to earthquake, relatively easy to warn
Graded streams
long-term tendency is toward a profile in which the amount of sediment entering a stretch of a stream is equal to the amount leaving it.
coral polyps
love volcanoes (tropical) extracts calcium carbonate from the seawater and secretes a limy skeleton around the lower half of its body
What is glacial transportation?
most happens under glacier melt streams
Wave erosion
most notable feature (Even tiniest) most because of storm waves the sandier the coast line, the quicker the erosion
What are the two types of glaciers?
mountain and continental
Describe Continental Glaciers
only 2 exist today outlet glacier ice shelf iceberg
What is the difference between overland flow and streamflow?
overland flow- water flowing overland & not in channel streamflow- digging in to surface creating channels, can carry more sediment (condensed flow)
Describe glacial movement.
partial melt aids movement plastic flow of ice basal slip movement is very slow and erratic
What is the difference between perennial, intermittent, and ephemeral streams?
perennial stream- a permanent stream that contains water the year-round intermittent stream- a stream that carries water only part of the time, during the "wet season" or during and immediately after rains ephemeral stream- a stream that carries water only during the "wet season" or during and immediately after rains
Periglacial Environment
periglacial= "on the perimeter of glaciation" over 20% of land patterned ground prological lakes (small & temporary) Washington's channeled scablands
What are saline lakes?
permanent desert lake extremely full of salt Dead Sea
What is tower karst?
residual karst features, in form of many steep sided hills, dominate some parts of the world- referred to as tower karst because of their almost vertical sides and conical hemispheric shapes
What is a fossil dune?
sandstone feature cross bedding- wind blown sand deposits
Coastal submergence: ria shorelines and fjords
sea level about 20 ft higher 125,000 years ago (inter logical) Ria- coastline with long series of estuaries Fjorded- deep glacial trough with bottom below sea level
Coastal Emergence
sea level about 400 ft lower 20,000 years ago (last glacial peak) wave-cut cliffs wave-cut platforms (make "L" shape) marine terrace- formed when a wave-cut platform is uplifted along a tectonically rising coast
What are tsunamis also called?
seismic sea waves (tidal waves)
How do caverns form?
solution along joints and bedding planes in limestone beneath the surface often creates large open areas called caverns. they are found almost anywhere there is massive amounts of limestone deposit at or near the surface
What are the different types of erosion by overland flow?
splash erosion-smallest sheet erosion rill erosion gully erosion
What is the difference between stalagmites and stalactites?
stalactite- where water drip hits the floor this companion feature forms where there drip hits the floor the companion feature called stalagmite forms growing upward they may grow until they form a column
What are the different channel patterns?
straight- very uncommon/very short sinuous- common/ bends&turns meandering- a lot curvier braided- Cimarron
What are the Glaciofluvial Features?
stratified drift outwash plain (material washed out of glacier area) esker (till that forms from clogged meltwater steam when ice is stagnant) kame (steep hells- sporatically pop up) lake
Describe the structure of the Mesa-and-Scarp Terrain
structure- plateaus erosion of escarpment edge (butte-erosional remnant having very small surface area and cliffs and pinnacle-smaller and further denudation)
Equilibrium Theory
suggests that slopes are adjusted to geomorphic processes so that there is a balance of energy- the energy provided is just as adequate for the work to be done. (has serious shortcomings in areas that are tectonically stable or have limited stream flow)
Deposition by Mountain Glaciers
terminal and recessional moraines lateral moraine medial moraine- forms in middle from 2 laterals "black and white candy cane"
Hot Springs
the appearance of hot water at Earth's surface usually indicates that the underground water has come in contact with heated rocks or magma has been forced upward through a fissure by the pressures that develop when water is heated. The result produces bubbling water out either continuously
Describe Davis' Geomorphic Cycle
the first and in many ways most influential model of landscape development 3 stages: youth maturity (drainage basin expands/ tributaries) old age (peneplain- flat, featureless landscape with minimal relief) rejuvenation- stream terrace, entrenched meanders
What are sinkholes?
the most common form of karst topography, occur by the hundreds and sometimes the thousands. They are rounded depressions formed by dissolution of surface carbonate rocks at joint intersections.
What are the different things that shape the shoreline?
tides eustatic sea-level change ice-push (as water freezes and thaws-pushes in to shorelines) organic secreations (coral reefs) Stream outflow (stream deposite) Coastal sediment transport (longshore currents- develop right off shore due to waves hitting at angle) beach drifting
What are the different types of erosion by streamflow?
undercutting rock fragments corrosion- erode and break down river sediment flow speed
Knickpoint Migration
upstream shift in location of a knickpoint due to erosion knickpoint- a sharp irregualarity (waterfall, rapid, or cascade) in a stream-channel profile
What is geothermal energy? What are the advantages and disadvantages?
uses heat of Earth's interior advantages-self sustaining/ doesn't run out disadvantages- not perfect/ if you extract more than can be pumped back
What is the difference between valleys and interfluves?
valleys- created by streamflow interfluves- high ground between valleys
What is glacial ablation?
wastage of glacial ice through melting and sublimation the lower portion of a glacier where there is a net animal loss of ice due to melting and sublimation
What are drainage basins?
watershed all water and terrain that drains toward the valley drainage divide- divide drainage basins usually reserved for major streams
What are special conditions of the desert?
weathering soil and regolith (bedrock exposed, weathered/rocky terrain) soil creep (helps smooth out landscape impermeable surfaces (when it does rain=lot of runoff) sand rainfall fluvial deposition wind basins of interior drainage (no outside outlet) vegetation
What is surface drainage?
where sinkholes occur in profusion, they often channel surface runoff into the groundwater circulation, leaving networks of dry valleys as relict surface forms. Most rainfall and snowmelt seep downward along joints and bedding planes, enlarging them by dissolution.
Wave Motion
wind generated swells- when wave moves past invitation point common during storms waves of oscillation waves of translation- break at shore swash- turbulance (rushes onshore after breaks) backwash- movement as it goes back out to sea