Geomorphology Test 2 definitions
Terms
undefined, object
copy deck
- broad, flat area inundated during high tides and exposed during low tides
- mud flat
- remnant column of rock in the ocean near the coast
- sea stack
- tides that form at 90 degrees to each other.
- neap tides
- tides that form when the sun and moon are aligned
- spring tides
- water that is piled up returns to the sea
- rip current
- the periodic swell of lake water
- seiche
- steeply sloped, cone shaped hill that occurs in tropical karst areas.
- Tower karst
- A gentle sloping tower karst
- cockpit karst
- karst with large amounts of water, vegetation, and high temperatures
- trapical karst
- Darwin's model for the formation of an atoll (1st model)
- fringing reef forms around an island, island sinks and barrier reefs extend to the surface
- 2nd model for atoll formation
- Glacial Control. flat coral left after sea-level drop; rain falls leaving depression in flat surface, sea level rises.
- lakes formed by the changes in evaporation rates and precipitation brought about by worldwide temp drops.
- Pluvial Lakes
- latitudes where most of the EArth's deserts form due to descending of heated air.
- horse latitudes
- Methods of wind transport
- suspension, slatation, and surface creep
- wind moves weathered material
- deflation
- faces of rock pitting
- ventifacts
- low ridges of sand with wavelengths from 0.5-2.5m
- ripples
- very small amounts of sand with the spires pointing downward
- barchan dunes
- dunes that form in areas of prevailant winds spires pointing upward
- parabolic dunes
- elongate dunes forming perpendicular to the wind
- transverse dunes
- dunes forming parallel tot he wind direction
- longitudinal dunes
- last ice age
- Wisconsin glaciation (20ka)
- forming of ice lenses underneat the ground, favoring ground waters
- ice segregation
- uplift associated with freezing groundwaters
- frost heave
- general upward movement associated with frost heave.
- upfreezing
- ice propogates downward pulling stones from the soil
- ice pull
- boulder freezes faster from the bottom pushing the boulder up
- ice push
- cylindrical needles of ice can push particles upward
- needle ice
- freezing and thawing can often change the grain size distribution by sorting
- frost sorting
- creep associate with frost heave
- frost creep
- flowing of saturated soil
- soliflifluction
- solifluction associated with frozen ground
- gelifluction
- large lobate tongue shaped masses of rock debris frozen with interstituent ice
- rock glaciers
- piles of boulders on the side of a mountain formed by frost wedging
- delsenmeers
- flat areas associated with glaciation from 3-13 degrees
- blockfields
- occuring in a glacial setting, flat areas greater than 13 degrees
- block slopes
- streams confined by valley walls
- blockstreams
- the top melting layer of permafrost
- active layer
- a lens of unfrozen ground between active permafost layer and permafrost layer
- talick
- depth of permafrost at which temp is constant
- zero annual amplitude line
- cracks that fill with ice, more prevalent in fine-grained sediment
- ice-wedge
- multiple ice wedges come together forming polygons
- ice-wedge polygons
- small dome-shaped hill of mount that is cored with ice
- pingo
- composed of interwoven laters of ice and peat
- palsas
- the collapsed landforms associated with the thawing of ground ice
- thermokarst
- fields of conical mounts
- mima-mounds
- distinct symmetrical geometric shapes in paraglacial zones
- pattern ground
- pediment with no residual knob left only a flat gently sloping surface
- pediment pass
- landform formed as a stream exits an area of high relief and enters a broad flat plain
- alluvial fan
- flat depositional surface wehere many indicidual alluvial fans meet
- bajada
- fry lake bed
- playa
- triangulat shaped protuberance in the shoreline which forms when a river meets a large body of water
- delta
- flat erosional feature is the end product of the cycle of erosion
- peneplane
- meandering river goes back to the process of meandering back and forth flattening out an area
- lateral planation
- formed by something perturbing the system resulting in incision leaving areas to the side outside the areas of erosion
- fluvial terraces
- each terrace is an erosional surface, not a depositional surface
- cut in bedrock terrace
- constructed by deposition, river incises into new level and then fills
- fill terrace
- river meanders back and forth creating deposition then cuts down through it and while dutting fills it back up
- cut and fill terrace
- similar to a pediment, relics of former flood plain, now dissected
- cyclic erosional surface
- surface formed by selective stripping of the low resistance surgace from high reisitance rocks leaving behind a low relief plane
- stripped structural surface
- due to uplift around a meander, the meander is stuck in its course
- entrenched meander
- ease at which fluids travel through rock
- permeability
- ratio of the colume of water that is drained by gravity from saturated sediments to the total volume of the material
- specific yield
- ratio of volume of water retained to the total volume
- specific retention
- volume of water at a given viscosity that will move in a porous medium in a unit time under a unit hydraulic gradient through a unit area measured at right angles to the plane
- hydraulic conductivity
- Darcy's Law
-
Q=PIA
Q=discharge
P=hydraulic conductivity (m/s)
I=Hydraulic gradient (no units)
A=cross sectional area (m^2) - upper surface of the zone of saturation
- water table
- subsurface area in which all porosity is filled with water
- zone of saturation
- geologic unit that can store and transmit economic quantities of water
- aquifer
- extends continuously from a land surgace downward through a material with high permeability
- unconfined aquifer
- bound both above and below with impermeable or nearly impermeable layers
- confined aquifer
- aquifer under enough pressure that, if allowed to connect to surface, water would flow freely to surface
- artesian aquifer
- groundwater becomes heated to high temps due to a heat source in the subsurface
- thermal spring
- landscape formed from dissolution
- karst
- compound sinkhole
- uvala
- large closed depression with flat alluvial fill
- polje
- dissolution depression intersecting the water table
- karst lake
- center of a sinkhole gets clogged with clay so no water can escape
- sinkhole pond
- dissolving of limestone walls along fissures or bedding planes that are structurally controlled
- solution chmney
- cercular cylinders with vertical walls that cut across fissures and bedding planes
- vertical shafts
- river flows into karst features under ground
- disappearing stream
- valley where large percent of drainage is underground
- karst valley
- remnant valley with all present drainage underground
- dry valleys
- fluvial valley that bruptly ends at a sinkhole
- pocket valleys
- valley flows away from a sinkhole
- blind valley
- area with an abundance of estuaries
- coast of submergence
- areas that are submerged during high tide
- tidal flat
- predominantly found in temperatures between 77 and 86 degrees and live less that 60 m of water
- coral reefs
- Darwins Atoll formation
-
1)seamount above surface
2)fringing reef forms around it
3)seamount sinks under weight and reef continues to grow
4)central island erodes or sinks enough to be completely submerged - big integrated root system of trees captures sediment and forms land
- mangrove
- masses of ice or granular snow formed by compaction or recrystallixation of snow lying largely or wholly on land and showing eveidence of past or present movement
- glacier
- the state between snow and ice
- firn
- under great pressure, ice can melt and still have a temp above freezing
- pressure melting
- melting and refreezing due to changes in pressure
- regelation
- glacier slides over it's bed
- basal sliding
- minor movement taken place by rotating of crystal grains within a glacier
- intergranular shifting
- crystals of ice are sheared (parallel to movement)
- intragranular shifting
- ice melts the refreezes downslope
- recrystalization
- decrease velocity and ice thickens
- compressive flow
- velocity increases and ice thins
- extending flow
- crevasse forming perpendicular to the flow direction
- transverse crevasse
- crevasse forming along sides of the calley pointing at an angle up-flow
- chevron
- crevasses forming parallel to the flow
- longitudinal crevasses
- crevasses causing ice preading in a radial pattern
- radiant crevasses
- alternations of light and dark on the surface
-
ogives (ridges and swells)
ridges form during summer
swells form during winter - glacier forming near pressure melting point
- temperate glacier
- glacier forming well below pressure melting point
- polar glacier
- glacier forming between the polar and temperate glaciers
- subpolar glacier
- glacier confined by walls everywhere
- alpine glacier
- smaller size alpine glacier
- cirque
- glacier much larger than a cirque glacier
- valley glacier
- glacier that drains ice from an ice cap or ice sheet to a lower elevation
- outlet glacier
- glacier connected to the ocean
- tidewater glacier
- glacier that discharges broad, radiating, flowing lobes
- piedmont glacier
- ice formation not confined by topography
-
ice sheet/cap
sheet= >50,000 km^2
cap = <50,000 km^2 - ice is added to a glacier
- accumulation
- ice is lost from a glacier
- ablation
- boundary between zone of accumulation and zone of ablation
- equilibrium line
- abrupt advance in glacial advancement rates
- glacial surge
- rock debris is picked up by a glacier and is dragger and scraped across the bed causing erosion
- abrasion
- melt-water freezes, as glacier moves it pulls rocks loose
- plucking
- curved depressions formed by the removing of rock flakes by plucking
- chatter marks
- sediment directly deposited by glaciers
- till
- sediment deposited from melt-water from glaciers
- outwash
- rocks acarried by glaciers not from original bedrock
- erratic boulder
- couplets of sediment deposited annually
- varves
- silt-sized quarts formed as glacer moves across landscape
- glacial flour
- wind-blown silt of glacial origin
- loess
- semi-circular hollow set in a mountain slope characterized by a steep headwall
- cirque
- shallow depression formed by nivation of the permanant snow banks
- nivation hollow
- freeze and thaw and mass wasting
- nivation
- a narrow thin ridge between two cirques
- arete
- spire between three or more cirques
- glacial horn
- horn sticking out through and ice sheet or cap
- nanatuk
- callet formed by a glacier rather than a river
- glacial trough
- step-like longitudinal profile of a glacial valley resembling a giant staircase
- cyclopean stairs
- chain of small lakes connected by streams within a glacial valley
- paternoster lakes
- a glacial trough that has been flooded by the arm of a sea
- fjord
- glacial valley that fills completely with a lake
- finger lakes
- depositional ridge built by material transported by glaciers
- moraine
- moraine forming where a glacier ends
- end moraine
- moraine formed by the advancement of a glacier
- push moraine
- moraine formed by the retreat of a glacier
- dead-end moraine
- multiple end moraines formed as a glacier retreats
- recessional moraine
- moraine formed on teh side of a glacier
- lateral moraine
- moraine formed by the accumulation of debris that form as two tributary glaciers come togher and later moraines become caught up between two tributary glaciers
- medial moraine
- moraine formed by two lobes of glaciers come together
- interlobate moraine
- moraine formed by till covered areas of low relief blacken ridges
- ground moraine
- linear ridges or hilss composed of till. streamlined forms with elongate axes oriented parallel to movement
- drumlins
- once streams that formed on top of the glacier, when glacier melts, a glacial ridge is formed
- esker
- depression within a glacier fills with sediment. when glacier melts you are left with a deposit
- kame
- depressions often filled with water formed by the melting of buried ice
- kettle
- deposit of sediment associated with lake between glacier and valley wall
- kame terrace
- deposits formed in fornt of the glacier from meltwater streams
- outwash plane
- broad celss of atmospheric circulation taht control climate
- hadley cells
- terminal velocity
-
when air resistance = acc due to gravity
V = (4PpgDp/3PCd)
Pp = density of particle
Dp = diameter of particle
Cd = drag coefficient
(sphere = .7, square = 2)
P = atmospheric density
g = acc of gravity - elongate erosional ridges parallel to the wind
- yardangs
- long longitudinal dune
- seif dune
- 3 or more sharp ridges taht extend radially froma point
- star dune