Geology Exam 4
parabolic dunes
- At the beach -Some vegetation (block sand) -wind come off shore, into the cursive
Star dunes
-A lot of sand -Wind come in different direction and constantly - Irregular shape
Depositional of desert
-Alluvial Fan -Playas
Shore line budget
-Balanced budget (sand in = sand out) -Positive budget (sand in > sand out) --> beach grow -Negative budget (sand out > sand in) --> stringing -sand in and sand out
types of dunes
-Barchan -Transverse -Longitudinal -Parabolic -Star
Depositional at Beach
-Beaches -spits -Barrier island
Erosional in desert
-Desert Pavement - Ventifacts - Blowouts -Mesa -Butte
Glacial
-Have to fall in continent to make Glacial -
Pacific Coast
-Narrowing of beach (dam all the rivers.) -Diff erosion
Barrier island
-Parallel to the shore line but not connective -Low ridges of sand
Submergent
-Subsidence of land irregular coastline - lower - non active plate tectonic
Mesas
-Table shape, a big flat rock mountain in desert. -Differential weathering. the layer of the top resistant to weathering.
Desert
-Vegetation < 25% of surface -Rain <10 in average annual rainfall - High evaporation rates.
Erosional at Beach
-Wave cut cliff and platforms -cave, arches and stacks
Size of wave depend
-Wind speed -Length of time that wind blow -Fetch: area of sea
Blowouts
-a depression on the land surface caused by wind erosion -Hole of deflation
Jetties
-at harbor or marines -2 wall parallel, perpendicular to the shore, stop sand from long short current
Alluvial Fan
-big fan shape of deposit of sediment.
Where does the sand on beaches come from?
-longshore current -rivers
Atlantic
-loss of barrier island -Sea level rise, hurricane
Flash floods water erosion
-move big particle, move in specific direction -dissolved load -suspend load -bed load
Role of water in Desert
-not a lot precipitation -the ground is to dry so infiltration can't o underwater -become runoff water.
Longitudinal dunes
-not much sand -wind come in different direction and converging. parallel to the wind direction
Wind erosion
-small sediment carry any where -suspend load -bed load
Emergent
-uplift of an area -Wave-cut cliffs, platform, stacks. -Active plate tectonic.
Wave refraction
-wave bending, alway hit you head on. one part slow down because of fiction and other just keep going then bend, and arrived at shore line parallel
Transverse dunes
-win flowing across the dun -a lot of sand -wind flowing in constant direction -not a lot of vegetation -perpendicular to the dune
stop sand movement
1. Building structures -Jetties -Groins - Breakwaters and seawall 2. Beach nourishment: dump sand in to beaches.
Cirque
A bowl shaped basin carved by a glacier (erosional)
Glaciers
A mass of ice on land that moves by plastic flow and basal slip Contains most of earth Freshwater. Glacier is melting
horns
A pointed, mountain peak, typically pyramidal in shape, bounded by the walls of three or more cirques.
karst topography
A type of landscape in rainy regions where there is limestone near the surface, characterized by caverns, sinkholes, and valleys
Permeability
Ability of rock or soil to allow water to flow through it path way to pull water out of the ground
continental glaciers (ice sheets)
Big, cover entered continent, if they run out of land they will travel to ocean, don't care what under it
Basal slip
Bottom part can slide with little water at the ground
Groins
Built 1 wall to stop erosion of sand. perpendicular to the shore line to stop sand.
Glacial erosion
Bulldozing plucking Abrasion
Glacial Landforms
Created by Erosion
Desertification
Degradation of land, especially in semiarid areas, primarily because of human actions like excessive crop planting, animal grazing, and tree cutting.
Beach
Deposit of sediment that extending landward out of ocean or lake.
cave, sea arch, sea stack
Differential erosion. wave eat rock created cave then keep eating to created arch, then rock collage and created stack.
Spits
Elongated ridge of sand extending into ocean, connect to land.
Wave
Energy travel through water. Energy come from storm that have potential energy. Energy travel in circular motion
City water systems in Texas replicate a flowing artesian system because in an artesian system the groundwater is not under pressure and needs to be pumped to reach the surface.
False
Erosion in a river will increase when velocity decreases and deposition in a river will stop if velocity decreases.
False
Granite, sandstone would generally make the best aquifers because it has high porosity and high permeability.
False
Karst topography is more likely to form in areas underlain by sandstone than by limestone.
False
Subsidence occurs slowly due to the erosion of limestone beneath the surface and sinkholes occurs slowly due to the withdrawal of fluids from the ground.
False
Erratics
Glacial move big rock way far away.
Spring water
Ground Water naturally flow out to the surface
cave
Groundwater dissolve rock
Artesion Well
Groundwater under super high pressure.
Porosity
Hold in the ground. Determine how much water hold under the ground.
water table
Is not fix because if there is a lot of rain the water table moves up. Changing seasonally
Ground water concern
Lowering of water table Easily contaminate
Weathering
Mechanical weathering -thermal expansion and contraction. -oxidation (iron in rock and oxidant in air)
Glacial Retreat
More melt in summer than snow fall in winter
Glacial Advance
More snow fall in the winter than melting in the summer
Sand come from?
Most of the sand on the beach come from river from continent and river.
U-shape Trough
Mountain area, V- shape valley change to U- shape valley called Glacial trough
Stratified drift
Move every small particle further because glacial melt in to water and only carry small pieces.
weathering at the beach
Physical: salt and Crystal grow, biological activity Chemical:solution, Hydrolysis, oxidation
Cause of Glacialtion
Plate tectonics Milankovitch cycles Volcanic Activity
Lateral Moraines
Rock and sediment that fall from ridges and are deposited on the sides of glacial valleys as the glacier retreats
Which would be the best structure to build in order to stop waves from eroding beach sand?
Sea walls
evolution of wave
Seas-->Swell--> Breakers
Water erosion
Sinkholes, Karst Topography, Cave
Hanging Valley
Small glacial can't cut down to reach to the bid glacial to go down and it stuck hanging in a higher place
How to make Glacier?
Snow (80%air, 20% solid)--> ice (10% air, 90% solid) snow keep falling get compression and compacted
Milankovitch Theory
The theory that cyclical changes in Earth's orbit and in the tilt of Earth's axis occur over thousands of years and cause climatic changes -Eccentricity: earth't orbit is vary, path we take around the sun change in 10000 year cycle from circle to elliptical. we can be way further or closer to the sun -Tilt: angle of tilt vary by a few degree. -Wobble: season change
As a wave travels through the ocean, water particles are actually traveling in a circular motion and simply end up where they originated as the wave travels through.
True
Caves are formed by erosion of limestone, but are often being "refilled" by deposition of limestone
True
City water systems in Texas repicate a flowing artesian system because in an artesian system the groundwater is under pressure and will rise above the level of the aquifer.
True
The water table will be lowered when more water is removed from an aquifer than is being replenished by infiltration.
True
Valley Glaciers
V shape flow from high to lower elevation follow the valley
Till
a jumble of many sizes of sediment deposited by a glacier
Sinkholes
a large surface crater caused by the collapse of an underground channel or cavern; often triggered by groundwater withdrawal
Arete
a sharp narrow ridge found in rugged mountains
Seawall
a wall to protect sand and beach from wave erosion
Medial
all the small lateral meet and move with glacial they meet up and make a big glacial.
Drift
any thing that glacial carry is call drift
Zone of accumulation
area snow fall in winter
Breakwater
built parallel to the shore line.
dripstone
calcium carbonate deposited by water droplets
Breakers
circular motion of energy hit the shore and break. -high, short length
abrasion (glacial erosion)
drag along with glacial
Fjords
drown glacial valley. sea rise and flood that valley. Narrow deep inlets of the sea set between high rocky cliffs
Playas
dry shallow lake bed in desert, crack.
ground moraine
end moraine move over time
zone of aeration
fill with air and water
Zone of Saturation
fill with only water
Barchan
flat floor, not vegetation, not a lot of sand
why wave refract
friction slow down at the certain part of wave.
Which of the following structures would be the best to build in order to build up the sand deposits on a particular stretch of beach by trapping the sand being transported by longshore current?
groins
Which of the following statements is correct about groundwater movement?
groundwater can sometimes flow above the level of the aquifer groundwater will generally move from areas of high water table to areas of low water table groundwater will move from areas of high pressure to areas of low pressure
zone of wastage
ice melt
seas
irregular, form far away from the shore. hight wave length not constant.
Calving
is a way of wasting; when a piece of glacial bake off and flow in to the water
Tradewinds
located 30^o to the equator, blow east to west. -Warm moist air rise, and condense and fall rain back down in the equator but the hit in the air still travel to the 30 north and 30 south.
Eskers
long, winding ridges of sediment deposited by meltwater streams that flowed in tunnels within, or under glaciers
Subsidence
low process with draw liquid under the ground
Hot spring
magma heats water, the water rises to the surface in West
Plastic flow
middle part can flow plastic, under pressure, ice deform plastically
Trade wind desert
moist air hit mountain and drop rain and hot air travel to the other side of the mountain created hot dry air.
plucking (glacial erosion)
pick up and carry rock along the way
Which of the following affect how much solar radiation reaches the earth, thereby affecting whether or not ice ages can occur?
precession of earth's rotational axis tilt of earth's axis eccentricity of earth's orbit
flowing artesian well
pressure surface is above the ground
non flowing artesian well
pressure surface is below ground level
Bulldozing glacial erosion
pushing glacial along the way
Sweels
regular of wave away from the origin, same high and length.
Ventifacts
rocks shaped by wind blown sediments sand flow and hit rock in one side.
Habood
sand storm
Aquifer
sandstone make the best Aquifer. layer of rock that we get water from.
What are some features that you would expect to find in an area with karst topography?
sinkholes caves disappearing streams karst towers
Balance budget
snow fall = snow melt
currency of glacial
snow fall and snow melt
Geysers
springs that shoot hot water and steam into the air
Buttes
steep, vertical erosion. Differential weathering in the vertical erosion.
Which of the following statements about glacial deposits is correct?
stratified drift is finer, sorted sediment carried by the meltwater of glaciers glacial till consists of sediment of various sizes deposited when a glacier melts erratics are large boulders carried long distances by glaciers
Abrasion
striations : scratch Glacial polish rock flour: glacial grant rock into flour
Which statements below are correct about the water table?
the water table represents the boundary between the zone of aeration and the zone of saturation the location of the water table can vary seasonally the water table can be lowered by over withdrawal of groundwater from an aquifer
What is true about a basic groundwater system?
the zone of aeration has pore spaces filled with air and water while the zone of saturation has pore spaces filled only with water The zone of saturation contains rock and soil in which only water fills the pore spaces while the zone of aeration contains rock and soil in which the pore spaces are filled with air and water.
Crevasses
top part, brittle
Which of the following statements about valley glaciers is correct?
valley glaciers follow existing topography and flow from high to low elevations
Water moves
water under the ground want to move to the ocean latterly Water wants to go where from the higher pressure to where the lower pressure.
Wave cut cliff and platforms (erosion)
wave slowly eat the rock, left with the steep cliff, by time land will move back ward, over time leave cut flat from.
Drumlins
whale shape mountain of glacial material, glacial move to the end of the tail.
End moraine
when glacial end and deposit all the material
Desert Pavement
wind come through and move all the sand and leave rock behind.
Dunes
wind push sand, sand stay in certain degrees,30-35 degree will fall and whole pound of sand will move that dunes