Geology 101 Midterm 2, Geology 101, Midterm 2. Skinner 2016
What is the most frequent and lethal of all natural disasters?
Floods
What is a radial pattern river?
Forms along a mountain peak or volcano
What causes porosity?
Fractures and vesicles in basalt, solution cavities in limestone, space between grains in sandstone and conglomerate, fractures in granite
What is stratified drift?
Glacial sediment that has been reworked by water, usually a river that erodes into the till and carries it away
What is a glacier?
Glacier:A body of ice located on land, that flows under its own weight. If it doesn't move, it's not a glacier
What are alpine glaciers?
Glaciers eroding mountains
How does ice flow in a glacier?
Glaciers move by the slow deformation of the ice by an increase in pressure from the overlying ice. This includes shifting and rotation of grains of ice, pressure melting lubricates ice, and displacement along slip planes
Where does sand come from?
Glaciers, rivers, artificial sources (beach restoration), Reefs
What was the pleistocene glaciation?
Global event that disrupted hydrologic cycle Severe climate change shifted ecology Plants died and animals migrated
What are the causes of mass movement?
Gravity, Fractures in unconsolidated dirt and rocks, stability of slope (angle of repose), Water, Planes of weakness, fire, slope angle and undercutting,
Groundwater erodes by
Headward erosion
What are star dunes?
Isolated sand hill with pyramidal form Formed in areas with no single prevailing wind direction
What are barchan dunes?
Isolated, crescent shaped dunes with horns pointing downwind Develop in areas of limited available sand with moderate winds from one direction
What explains the shape of this delta?
It 's shape was made by fluvial (river) deposition
How does altitude affect the atmospheric pressure?
It drops the higher up you go because earth has a low density.
How is ice wedging important in preparing rocks for chemical weathering?
It enlarges fractures and cracks, thereby increasing the surface area of the rock
How much bigger does water get when frozen?
It grows by 9%
How do glaciers erode the surface they are on?
Ice wedging, and by plucking up loose fragments of rock. as the glacier moves, the rocks on the bottom are dragged along, creating striations.
What is a thermal spring?
If water percolates deeply enough into the crust, it will be heated as it comes into contact with hot rocks. The water from hot springs in non-volcanic areas is heated in this manner. In active volcanic zones such as Yellowstone National Park, water may be heated by coming into contact with magma. This water then travels to the surface because of pressure.
What is the difference between downcutting, headward erosion, and slope retreat?
In downcutting, the river becomes deeper. In headward erosion, the river becomes longer. In slop retreat, the river becomes wider.
What is a back swamp?
In geology backswamp is the section of a floodplain where deposits of fine silts and clays settle after a flood. Backswamps usually lie behind a stream's natural levees.
What is the difference between a rock fall and a rock slide?
In rock fall, single large rocks fall off a steep surface because of a push. In a rockslide, enormousxf entire sides of mountain travel quickly down a slope.
How do you classify a kind of mass movement?
Includes all types of slope failures Classified by Type of motion Type of material Rate of movement
What is a lateral moraine?
Lateral moraines are a product of rock fall onto the margin of a glacier. The rock debris are carried along the glacier edge as it moves towards the snout.
What are the factors that determine climate?
Latitude (proximity to the sun) Altitude (air molecules thin the higher up you go) Terrain Proximity to large water bodies Ocean currents Snow cover
Which of the following gases makes up the greatest percent of Earth's atmosphere?
Nitrogen (N2)
Which of the following gasses makes up the greatest percent of Earth's atmosphere?
Nitrogen (N2)
What is our atmosphere composed of?
Nitrogen, Oxygen, and Argon=99.9% Nitrogen=78%, Oxygen 21%, Argon .9%
Valleys carved by glaciers tend to be shaped like the letter _____, whereas valleys carved by water tend to shaped like the letter _____.
"U" ; "V"
This block diagram shows a karst area. Where is the sinkhole?
(A)
This block diagram shows a karst area. Find the cave
(B)
Where in this illustration does the total annual amount of snow fall exceed the total annual amount of snow melting?
(E)
What is the Magnetosphere?
5th sphere. the outermost layer of the atmosphere, where electrically charged particles are trapped by earths magnetic field. This layer protects other layers from solar radiation
Approximately what percentage of the Earth's surface is covered with water?
70
How much of the hydrosphere is in the oceans?
97%
What are parabolic dunes?
A "U" or "V" shaped dune with long trailing arms Common in coastal areas with abundant sand, and prevailing ocean winds Migrate landward Typically vegetated
How do particles of water move as a wave passes?
A Particle of Water Moves in an Orbit, a Nearly Circular Path, as the Wave Passes.
As the velocity of flow decreases, _____. flow tends to become more laminar the maximum flow velocity decreases suspended sediment starts to be deposited
All are correct
What is a slide?
All the land moves as one large unit, or several small ones along a well-defined slippage plane.
Longshore drift moves water and sediment
Along the beach in a zig zag path
This illustration shows the various features of a river floodplain. Where is the pointbar?
Along the inside edge of the curves in the river
What is wave refraction?
An example of refraction is when waves approach a straight shoreline at an angle. The part of the wave crest closer to shore is in shallower water and moving slower than the part away from the shore in deeper water. The wave crest in deeper water catches up so that the wave crest tends to become parallel to the shore.
What is an underwater landslide?
An underwater slide is like a landslide on land, except that it takes place under water. Slides occur when a slope fails to hold itself up. The San Andreas Fault could trigger an underwater landslide and a big enough one could generate a tsunami
Why is cross bedding present in sand dunes?
As more sediment piles on top the weight causes the underlying sediment to cement together and form cross beds. the wind is blowing the sand over the dunes and it is preserved as the water table rises.
What happens when a glacier reaches equilibrium?
At equilibrium, a glacier stays the exact same size. If input is less than output, the glacier shrinks and vice versa
What water feature is built from the crater of a volcano?
Atolls
This block diagram shows a karst area. Which letter shows a cave?
B
Which type of mass movement includes a large proportion of ash derived from a volcanic eruption? A. stromboli B. lahar C. debris flow D. wadi
B. Lahar
Which of the following types of mass movement takes place most gradually? A. slump B. creep C. rock slide D. mudflow
B. creep
The immediate cause of incidents of mass movement is A. electromagnetic attraction B. gravitation C. magnetism D. friction
B. gravitation
The principal difference between a debris flow and a mudflow is ____________. A. the shape of the path taken by the moving mass B. the grain size of the moving mass C. that the former mass contains abundant water whereas the latter is dry D. that the former mass contains pyroclastic debris from a volcanic eruption
B. the grain size of the moving mass
The lowest elevation to which a stream can downcut is the _____.
Base Level
What are the causes of climate change?
Causes for climate change may include Solar output is not constant Milankovitch cycles - Earth orbit and axis tilt Changes in atmospheric composition Position of continents and ocean circulation
What are the causes of glaciation?
Causes for climate shift are not well known Glaciation is an unusual event Earth's climate has generally been milder than today High precipitation rates are needed for glacial growth
How are caves formed?
Caves are formed by the dissolution of limestone. Rainwater picks up carbon dioxide from the air and as it percolates through the soil, which turns into a weak acid and mixes with the ground water. This slowly dissolves out the limestone along the joints, bedding planes and fractures, some of which become enlarged enough to form caves.
During _____________ weathering, the original minerals can be destroyed, and new minerals formed that are stable at Earth's surface.
Chemical
What is the difference between weather and climate?
Climate-Long term conditions (Ice Age). Weather-short term (two weeks or less)
What are emergent coasts?
Coasts where the sea is receding and more coastline appears
Most stream tributaries occur in which part of a river system?
Collecting System
What are Yardangs?
Columns of rock that are slowly flattened by abrasion. elongated, streamlined ridges. The flat surface at the front is directly created by abrasion, so you can tell which way the wind is blowing.
How does wind erosion in the desert effect reefs on the shore?
Coral and other organisms mistakenly eat dirt blown into the ocean by the wind. This kills reefs.
What is creep (in deserts)?
Creep is when the wind blows large boulders across the ground. They move slowly and cannot leave the ground because they are so heavy
What is solifluction?
Creep that occurs in permafrost. Melting of soil water occurs from the surface down, but the deep soil is frozen and so it doesn't accept any water. The surface soils get all the water and can't support it all, so they begin to flow
How are crevasses formed?
Crevasses are formed when parts of a glacier are moving more quickly than others.This can happen in any zone of the glacier
Which of the following factors DECREASES the risk of mass movement? A. nearby earthquakes B. excavation into the base of a hill C. adding weight to the top of a hill D. adding vegetation to the side of a hill
D. adding vegetation to the side of a hill
Which of the following types of mass movement is likely to move most rapidly? A. slump B. creep C. rock slide D. debris slide
D. debris slide
Which of the following types of mass movement is least coherent (most like a liquid)? A. slump B. creep C. rock slide D. mudflow
D. mudflow
What is a recessional moraine?
Recessional moraines are often observed as a series of transverse ridges running across a valley behind a terminal moraine. They form perpendicular to the lateral moraines that they reside between and are composed of unconsolidated debris deposited by the glacier.
What is a barrier reef?
Reefs separated from the mainland by a lagoon
What is a platform reef?
Reefs that grow in isolated oval patches on continental shelves.
What is differential flow velocity?
Refers to the different speeds at which a glacier (or any body of movement) is flowing.
What is regolith?
Regolith is a layer of loose, heterogeneous superficial material covering solid rock. It includes dust, soil, broken rock, and other related materials and is present on Earth, the Moon, Mars, some asteroids, and other terrestrial planets and moons.
Which minerals are least susceptible to chemical weathering?
Reistant Quartz Muscovite Feldspar Biotite Amphiboles Olivine Limestone Not resistant
What was the Gift of the Nile?
Rich soil washed down the Nile, giving farmers great plants. When the Aswan dam was put in, the Gift of the Nile no longer existed
What is a trellis?
Ridges of rock that are elongates cause a flowing river to create smaller offshoots flwing perpendicular to it.
What is a point bar?
River's deposit their sediment on the inside edges of the flow, creating point bars where sediment buildup occurs
Strictly speaking, which of the following types of mass movement is a landslide? slump creep rock slide mudflow
Rock Slide
What is joint block separation and how does it help chemical weathering?
Rocks breaking along a system of joints so one large rock becomes many smaller rocks, all with their own sides. This leaves more space for chemical weathering to occur.
What are ventifacts?
Rocks that have suffered abrasion from natural sandblasting. These have a polished rock surface
The type of mass movement shown in this drawing is a
Rockslide
How can atmospheric circulation move water?
Temperature helps evaporate the water, which goes into the air. Warm air holds more water, and also rises and moves towards the poles.
What determines temperature in global climate change?
Temperature is controlled by: Solar output Composition of the atmosphere* Albedo Ocean circulation and position of continents Changes in the Earth's spin or orbit
How does wind pick up sediments?
Through the bernoulli effect. Wind envelops the sand grain and exerts a lot of pressure below the grain and less above the grain, causing the grain to be lifted and dragged. (lift-formation of a zone of low pressure around the grain. Drag-impact of air molecules on the grain)
What is the source of water for the western and southern United States, respectively?
Western: Northwestern Pacific Ocean. Southern: Atlantic Ocean near the Caribbean Islands
What is deflation?
When a blowout gets water in it, which further erodes the surface of the rock. When the water evaporates, blowout takes more loose sediment that the water created. This is a cycle that lasts as long as the deflation stays above the waterbed
What are outwash plains from a glacier?
When a glacier ends, but water continues past the moraines
What is a rectangular river?
When a river creates new fractures to run through the bed rock. Often comes in perfect right angles
What is a baymouth bar?
When a spit completely blocks off a bay or estuary
What happens when a wave breaks?
When a wave gets big enough that the peak folds in on itself
What is a confined aquifer?
When an aquifer is underneath a layer of impermeable rock. This creates tension, which can result in artesian springs. They can only be recharged in the highlands.
What are alluvial fans?
When distributaries run into a dry area. This happens when it rains in the desert
What is isostatic adjustment?
When glacial ice pushes on a continent and makes it sink. Once the glacier is gone, the continent rises again. This is happening today.
What are natural discharge springs?
When ground water meets with a steep drop off and instead of following the landscape, simply comes out of the ground into a waterfall
What is a spit?
When longshore drift extends the beach across a bay or estuary.
What is leach?
When minerals dissolve directly in water and the ions are flushed away.
What is a solution valley?
When sinkholes grow merge to form irregular closed depressions.
What is recharge?
When water from an outside source enters the groundwater supply
What is abrasion/natural sandblasting?
When wind carrying particles of sand blows into a rock surface. The sand erodes the surface of the rock depending on which direction the wind is blowing
What are wind driven currents?
When wind impacts the surface layer of the ocean, it drives it forward. Prevailing winds push water in one direction and then water is eventually deflected by land. This forms roughly circular patterns
What is lag deposit?
When wind picks up all the small particles on the ground, only leaving the biggest rocks. These rocks left behind are lag.
What is avulsion?
avulsion is the rapid abandonment of a river channel and the formation of a new river channel. Avulsions occur as a result of channel slopes that are much less steep than the slope that the river could travel if it took a new course.
This drawing shows _____ dunes.
barchan
The lowest elevation to which a stream can downcut is the _____.
base level
Braided streams _____.
consist of a series of intertwined channels that are overloaded with sediment
Water flowing from hot springs _____.
contains more dissolved minerals than does water flowing from cool springs
two things required for an ice age to happen are:
continents in polar regions, tilt in the earth's axis
Which of the following is NOT a type of physical weathering?
conversion of feldspar minerals to clay and soluble material
Which of the following types of mass movement takes place most gradually?
creep
salinity: salty water is more ____ than fresh water
dense
anything behind the line of equilibrium on a coast line is considered the zone of _____
deposition
alluvial fans occur in ______ and when the river meets a _____ valley floor
deserts, flat
What are Horizons?
different layers of soil down to bedrock
What happens when a chunk of sediment is removed from a river bed, making the river into a waterfall?
Whenever a factor in a river changes, it moves towards equillibrium. In this kind of situation, a river would begin to deposit more sediment into the space until the space is filled again.
What is a hanging valley?
Where a valley is met with a steep cliff drop-off because the glacier that formed the valley was not able to continue eroding the surface
What precipitation is expected in a desert climate?
Where precipitation rate is less than evaporation rate. Precipitation is less than 25 cm/year.
What are the distributaries of a river?
Where the river runs into the ocean
What is the main source of erosion in the desert?
Wind
Strictly speaking, is a slump a landslide?
Yaaaas
What are the three parts of a glacier?
Zone of accumulation - snow Zone of ablation - melt Snow line - boundary
What creates this unique river pattern?
a braided stream has more sediment than it can carry
Crevasse
a break in the levee - during flood season
What are headlands?
a coastal landform, a point of land usually high and often with a sheer drop, that extends out into a body of water.
What are stacks?
a column of rock standing in the sea, remaining after erosion of cliffs.
What are crevasses in a glacier?
a deep open crack, especially one in a glacier. Crevasses cause a glacier to become brittle and more easily breakable. Crevasses usually form at a right angle to the flow of the glacier
splay
a delta formed by the water diverted by the crevasse
What is a natural Levee?
a deposit of sand or mud built up along, and sloping away from, either side of the flood plain of a river or stream
What is the Ozone?
a gas in the stratosphere, absorbs uv
What are cirques?
a half-open steep-sided hollow at the head of a valley or on a mountainside, formed by glacial erosion. the head or top of a glacial valley
What is a joint plane?
a joint is a fracture dividing rock into two sections that have not moved away from each other. A joint sees little or no displacement. In other kinds of fracturing, like in a fault, the rock is parted by a visible crack that forms a gap in the rock.
What stripped the slope (in the middle of this photo) of trees and other vegetation?
a large landslide
What is a drumlin?
a low oval mound or small hill, typically one of a group, consisting of compacted boulder clay molded by past glacial action.
What is salinity?
a measure of all the dissolved salts in sea water
What is a terminal moraine?
a moraine deposited at the point of furthest advance of a glacier or ice sheet. After deposition, the glacier dies
trellis drainage pattern
a pattern in which the tributaries join the main stream at right angles
What are atolls?
a ring-shaped reef, island, or chain of islands formed of coral. Originating from a volcano that is now submerged
graded stream
a stream at equilibrium (no waterfalls)
What is a rip current?
a strong, localized, and rather narrow current of water. It is strongest near the surface of the water, and it moves directly away from the shore, cutting through the lines of breaking waves.
What is the jet stream?
a very fast moving stream of cold air delineating unstable polar air and the warm moist air from the south
loess is ____ from glaciers and ____ all over the world
dust, blown
What is geothermal energy?
energy from groundwater
regular shoreline
energy is different on different places on the shoreline
The cone of depression surrounding a well
enlarges and deepens as the rate of pumping increases
With regard to global atmospheric circulation, moist warm air ascends in the
equatorial regions
if you build a dam on a river, the beach created by that river will eventually ____________
erode
The migration of sand dunes results from
erosion of sand on the windward side and deposition on the slip face.
When sea level rises, the ocean may invade a river valley, producing a nearshore body of water of mixed and variable salinity termed a(n) _____.
estuary
Major sources of water in the continental hydrologic system comes from_____...
evaporation from oceans at 20 to 40 degrees north and south
debris flow
everything falls down a hill, rock fragments, mud, water
An atoll normally
evolves from a fringe or barrier reef
Which of the following common rock-forming minerals weathers to form most of the clay found in soils and regolith?
feldspar
What is the saltation load?
fine particles bouncing along the river bottom because they are too large to be picked up and carried
what 3 things trigger a landslide?
fire (loss of vegetation), water, earthquake
When sea level rises, causing the ocean to fill a glacially carved valley, a _____ results.
fjord
Which of the following increases the risk of mass movement?
flooding the sediment with water beyond saturation
Where are rocky coasts found?
in Areas of High Wave Energy.
Large continental glaciers are found today
in Greenland and Antarctica
Joints aid in chemical weathering by
increasing the surface area exposed to weathering agents
how do we get hematite?
iron-rich minerals are oxidized
The topography of the water table _____.
is a subdued (less steeply sloping) mimic of surface topography
Moving away from its headwaters, the flow of a stream becomes more _____.
laminar
exfoliation
spheroidal weathering - rock breaks apart in layers
In this cross section of a valley, slope A is diagonal plane of rock, and a highway built into it. slope A is downhill from the highway
stable. There are no planes of weakness sloping toward the highway.
What does groundwater deposition create?
stalactites, columns, stalagmites, fossils,
on land crossbedding
steep angles
Chesapeake bay was formed by
stream erosion and a rise in sea level
Alluvial fans tend to form where
streams flow into dry basins in arid regions
deserts are formed in
subtropical high pressure belts
Most of the world's major deserts are located in the
subtropical high-pressure belts
What are the different types of deserts?
subtropical, rain shadow, cold wind, distance, and polar.
urbanization, cement and roads increase:
surface runoff
The products of ice wedging often accumulate at the bases of cliffs to form piles of angular rock fragments called
talus
A lake that forms within a bowl-shaped depression formed by a mountain glacier is termed a(n)_____.
tarn
What are the characteristics of temperate climates?
temperature ranges from 0C to 25C. Between 35o and 60o N & S of the equator. Temperature varies throughout the year. Precipitation may fall at any time. Large rivers may form. Moderate weathering & rich soils
If you found ancient rocks in Antarctica that had formed in an organic reef, what could you suggest?
that the climate has changed and that Antarctica has moved
What is the major source of water that falls as precipitation on the southeastern United States?
the Atlantic Ocean near the Caribbean islands
What is a slump block?
the block that moves in a landslide on a spoon shaped slippage plane. Block moves downward and outward Usually has multiple slippage planes. Displacement of the bedding plane provides evidence for movement
What is thermohaline circulation?
the circulation of ocean water caused by changes in temperature and density. This circulation affects the both the top and bottom layers of the ocean and can turn over the entire world ocean.
hydraulic head
the difference in elevation in the water table, causing flow
talus cone
the dirt that accumulates at the base of a cliff
This is a map of Anvil Cave, Alabama. The growth of this cave system was probably controlled by
the distribution of fractures along which ground water flowed.
Cohesive strength
the force keeping material stationary on the earth (gravity fights it)
What is glacial plucking?
the glacier plucks up large fragments of rock from the ground and moves them along with the ice. When they rip up the ground, it's called abrasion.
The major force in the generation of tides is
the gravitational attraction of the Moon
What is sea ice?
the ice on the polar regions
What is base level?
the lowest level to which a river can erode its channel. It has to get to either the ocean, lake, or an even bigger river or stream
What is saltation?
the movement of hard particles such as sand over an uneven surface in a turbulent flow of air or water. The wind blows the particles and they bounce along the surface of the earth
What is longshore drift?
the movement of material along a coast by waves that approach at an angle to the shore but recede directly away from it.
snow in the wasatch mountains comes from...
the northern pacific ocean
What is the major source of water that falls as precipitation on the western United States?
the northwestern Pacific Ocean
What is the bed load?
the particles that roll along the bottom of a stream
What is headward erosion?
the process by which a river erodes its source region, seemingly lengthening its channel in a direction opposite to that of flow. When water falls on a planer surface, it has a tendency to flow along slope in form of an oscillating stream.
Locally, the climate may differ from that dictated simply by latitude (position north or south of the equator) because of
mountain ranges that alter atmospheric flow patterns. cold and warm surface currents in the oceans. high elevations **all of the above**
the type of mass movement shown in this drawing is (mountain rain and mud coming out of rock canyon)
mud flow.
Sediment buildup on either side of a stream channel produces _____.
natural levees
dendritic drainage pattern
normal - treelike - from mountains to ocean
Chemical weathering would progress most rapidly in which location?
northern South America
long shore drift has ________ angles
oblique
three orbital irregularities that cause an ice age are:
obliquity, eccentricity, precession
sheeting
the rock that basically cleaves horizontally because of release of pressure (not cleavage)
Weathering is a near-surface phenomenon, but in some regions chemical decomposition may operate tens of meters below the surface if
the rocks are highly fractured
competence
the size of the largest particle the stream is able to carry. Can change with velocity.
Angle of repose
the steepest slope at which the loose material will remain at rest
The water table is
the surface that marks the top of the saturated zone
What is a bedding plane?
the surface that separates each successive layer of a stratified rock from its preceeding layer
What is Surface water?
the thin, warm layer of water on top of the deep water
What is the coriolis effect?
the winds spinning on the earth because of the planet's rotation. In the northern hemisphere, earth deflects winds to the right, and in the southern hemisphere, they are deflected to the left. In the end, the spin of the earth is greater at the equator and smaller at the poles.
The majority of fresh liquid water within the Earth exists in _____.
pores within rock and sediment
After granite has weathered and most of the igneous minerals have been altered to other minerals, which igneous mineral will probably NOT have been affected?
quartz
__________is not weathered because it's resilient
quartz
In the region immediately surrounding an isolated volcano, a _____ drainage network is expected.
radial
Ice is a substance with a high albedo, which means it _____.
reflects most of the light that falls upon it. This keeps glaciers from melting.
The general term for the blanket of loose rock debris that covers large areas of Earth's surface is
regolith
coasts are slightly modified by modern marine processes because of:
rise in sea level
v shape valleys come from
rivers
beach sand comes from ______ and are acted on by ______ ________ _________
rivers, long shore drift
Wind transports material by
rolling saltation sliding suspension
sand moves through
saltation, creep, deflation, lift
The zone below the water table is the zone of
saturation
Which of the following is the most likely trend in the evolution of coastal features?
sea cave, sea arch, sea stack, sea cliff
Which of the following is NOT a depositional feature?
sea stack
nuclear waste should be buried in
shale
wind blows on the ______ end of a sand dune
shallow
Why is the Chesapeake bays shoreline irregular?
there was a river that created a valley, then the sea level rose and filled the valley with water
Sediments deposited directly by glaciers as they melt are termed _____.
till
the sand bar connecting an island to the mainland is called a ______
tombolo
in a river cross section, the ____ ______ of the river contains the fastest flow
top middle
waves _____ energy and create _______ motion
transfer, circular
What are greenhouse gases?
trap heat in the troposphere - carbon dioxide
we live in the
troposphere
The most important layer of the atmosphere for geologic development of the surface is the
troposphere, because this is where weather and the decay of rock occurs.
The atmosphere is divided into several layers based on temperature gradients. In order upward, they are:
troposphere, stratosphere, mesosphere, magnetosphere.
How do you classify a mass movement?
type of motion, type of material, rate of movement
In this cross section, slope B is likely to be
unstable because of bedding plane slippage.
In this cross section, slope B is likely to be? Slope B is above the highway on a slanted angle
unstable because of bedding plane slippage.
In this drawing, the net movement of sand is
up the coast (toward the upper side).
As compared to humid climates, rates of chemical weathering in deserts are _____.
slower
Which of the following types of mass movement travels down a curved surface?
slump
What is a creep?
soil and regolith moving extremely slowly. Caused by a combination of heaving of soil (expansion & contraction is the primary cause), Wet-dry cycles, and Freeze-thaw cycles
gelisols
soil in polar regions that's gelato
What are mollisols?
soil that's organic rich and morbido
The source of energy that "fuels" motion in the ocean-atmosphere system is
solar energy
_____ _________ drives ocean currents through convection heat
solar radiation
What do strong trade winds do to the Ocean?
They cause deep, cold, nutrient-rich water to well upward.
What is oxidation?
combination of oxygen and another mineral to make a new mineral.
What is an arete?
• Area between two glaceris-a sharp crested ridge bounded by two cirques
What is the mineral that weathers to form most of the clay found in soils and regolith.
Feldspar
What are three things the coriolis afect does?
-the inertial force generated by the planet's rotation -it divides atmospheric circulation into latitudinal zones -it deflects surface winds
How much of the hydrosphere is in ground water?
.6%
What is wave base?
1/2 of Wavelength
At the present, glaciers cover about _____ of the surface of the continents.
10%
The current interglacial interval began a little more than _____ years ago.
10,000
How much of the hydrosphere is in glaciers?
2%
What is the stratosphere?
2nd Sphere. ozone layer helps to absorb UV rays. Temperature increases with altitude because of the ozone layer. Will not mix with the troposphere. This is already higher than planes fly
What percentage of seawater, on average, consists of dissolved salt ions?
3.5%
What is the angle of repose?
34 Degrees
How much salt is in the ocean?
35 g/kg average 35,000ppm (<500 in drinking water)
What is the mesosphere?
3rd Sphere. Temperature increases with altitude.
What is the thermosphere?
4th sphere. Traps the sun's heat and so the temperature increases with altitude. Gas ions form here and UV rays are absorbed
What is an ephemeral stream?
A basin in the desert that only flows when it rains
What is a hydraulic head?
A combined measure of the elevation and the water pressure at a point in an aquifer which represents the total energy of the water; since ground water moves in the direction of lower hydraulic head (i.e toward lower energy), and hydraulic head is a measure of water pressure, ground water can and often does flow 'uphill'.
What is a subtropical desert?
A desert that lies too close to the ocean so when evaporation happens, the clouds are too high up in the sky right away to come down on it. All the rain passes it up.
What is granular disintegration?
A form of weathering where the grains of a rock become loosened and fall out, to leave a pitted, uneven surface.
What is a playa?
A lake in the desert that only fills during flooding
What stripped the slope (in the middle of this photo) of trees and vegetation?
A large landslide
What is a river crevasse?
A local break in a levee that forms during periods of high runoffs and causes flooding from the stream.
What is a spit?
A long piece of sand that was slowly deposited by beaches further up
What is the longshore current?
A longshore current is an ocean current that moves parallel to shore. It is caused by large swells sweeping into the shoreline at an angle and pushing water down the length of the beach in one direction.
What is a medial moraine?
A medial moraine is a ridge of moraine that runs down the center of a valley floor. It forms when two glaciers meet and the debris on the edges of the adjacent valley sides join and are carried on top of the enlarged glacier.
What is crystal growth?
A part of physical weathering. Salt particles get inside rock and wood and grow, splitting the materials apart
What is a divide?
A piece of land that separates rivers
What is a plunge basin?
A plunge pool (or plunge basin or waterfall lake) is a depression at the base of a waterfall created by the erosional force of falling water and rocks where it lands.
What is a delta?
A river delta is a landform that forms from deposition of sediment carried by a river as the flow leaves its mouth and enters slower-moving or standing water. This occurs where a river enters an ocean, sea, estuary, lake, reservoir
What is downcutting?
A river that erodes downward through it's bed
What is a sand dune?
A sand dune forms when a hill or ridge disrupts the flow of air. The air must drop sediment to get over the ridge, so one side of the ridge becomes full of sand, and eventually a hill forms.
The principal difference between a slump and a debris slide is ____________. A. the shape of the path taken by the moving mass B. the grain size of the moving mass C. that the former mass contains abundant water whereas the latter is dry D. that the former mass contains pyroclastic debris from a volcanic eruption
A. the shape of the path taken by the moving mass
What is a laminar flow?
A straight flowing body of water, usually a river. This is caused by either high velocity or low velocity.
What is a perennial stream/?
A stream that is always flowing
What is a braided stream?
A stream that splits into many smaller streams due to containing more sediment than it can carry
What is a beach?
A strip of Sand or Gravel that Extends from the Low-Water Line Inland to a Cliff or Permanent Vegetation.
What is a Talus Cone?
A talus cone is formed by the dry accumulation of loose. scree material. The debris cones come out of a high—angle. bedrock ravines and accumulate against the valley bottom.
What is a trellis stream pattern?
A trellis drainage pattern occurs where subparallel streams erode a valley along the strike of less resistant formations. These beds are usually steeply dipping and may be part of a fold system. The tributaries often intersect at right angles where a notch called a water gap cuts through a harder formation.
What is a truncated spur?
A truncated spur is a ridge that descends towards a valley floor or coastline from a higher elevation, that ends in an inverted-V face and was produced by the erosional truncation of the spur by the action of either streams, waves, or glaciers.
Which of the following types of mass movement always travels down a curved surface? A. slump B. creep C. rock slide D. mudflow
A. slump
Ventifacts are a product of
Abrasion
What are blowouts?
Blowouts are sandy depressions in a sand dune ecosystem (psammosere) caused by the removal of sediments by wind. Commonly found in coastal settings and arid margins, blowouts tend to form when wind erodes into patches of bare sand on stabilized vegetative dunes.
What is a rock fall?
Boulders and other debris are dislodged from a steep cliff, falling to the ground below.
How are seasons decided?
By the angle of tilt between the earth's axis and the sun
These drawings show the various stages of evolution for a hypothetical coastline. The correct order for these drawings is
C, A, B, D.
Moisture among sediment grains ____________. A. always increases the likelihood of mass wasting B. always decreases the likelihood of mass wasting C. can promote stability if present in small amounts, but promotes mass wasting if sediment is saturated D. can promote stability if the grains are saturated, but a small amount of moisture has little effect on the likelihood of mass wasting
C. can promote stability if present in small amounts, but promotes mass wasting if sediment is saturated
The principal difference between a debris flow and a debris slide is ____________. A. the shape of the path taken by the moving mass B. the grain size of the moving mass C. that the former mass contains abundant water whereas the latter is dry D. that the former mass contains pyroclastic debris from a volcanic eruption
C. that the former mass contains abundant water whereas the latter is dry
What is a caprock?
Caprock or cap rock is a harder or more resistant rock type overlying a weaker or less resistant rock type.[1] Common types of caprock are sandstone and mafic rock types. In processes such as scarp retreat, the caprock controls the rate of erosion of the scarp. As the softer rock is cut away, periodically the caprock shears off. Caprock is also found on the top of mesa formations.
The principal difference between a lahar and a mudflow is ____________. A. the shape of the path taken by the moving mass B. the grain size of the moving mass C. that the former mass contains abundant water whereas the latter is dry D. that the former mass contains pyroclastic debris from a volcanic eruption
D. that the former mass contains pyroclastic debris from a volcanic eruption
What is coastal upwelling?
Deep, cold, mineral rich ocean water coming up on the coast. Winds blowing across the ocean surface push water away. Water then rises up from beneath the surface to replace the water that was pushed away. This process is known as "upwelling."
How are deserts formed?
Deserts are formed as less water becomes available. Because of global warming, deserts are growing by 23,000 square feet every year
What are polar deserts?
Deserts in regions like antarctica and the north pole. Although they have ground moisture, so little snow falls every year that it is considered a desert
What are cold wind deserts?
Deserts like the Atacama where cold, dry wind comes off the ocean, whipping up all the moisture from the air and ground. This is the literal driest place on earth (including ground moisture and precipitation)
What are rain shadow deserts?
Deserts that are placed next to large mountains that keep the clouds from coming over
What are distance deserts?
Deserts that are too far away from the ocean. The Gobi desert is one that is so far away that evaporation all lands in Europe and never makes it there.
What are longitudinal dunes?
Develop in areas of limited available sand with strong, bi-directional winds Form evenly spaced ridges
What is the suspended load, and the dissolved load?
Different sizes of particles being carried by the stream
What is global climate change?
Different than continental movement. Changes the size of global climate zones Temperature is most important
What are the factors affecting stream flow?
Discharge Gradient Velocity Sediment Load Base level
How can you distinguish a rip current and how can you get out of one?
Discoloration of water and sea foam. Swim parallel to the shore until you are out of the current and then swim into shore
What is dissolution?
Dissolution is an especially effective method of chemical weathering in rocks that contain either magnesium carbonate or calcium carbonate, two substances which are easily dissolved by water or other acidic solutions.
What are the affects of overpumping?
Dry wells, cone shaped depressions, saltwater intrusion, settling
What is undercutting?
Erosion of material at the base of a steep slope, cliff, or other exposed rock.
What is sheeting?
Exfoliation. Physical weathering. The process by which thin sheets, slabs, scales, plates, or flakes of rock are successively broken loose or stripped from the outer surface of a large rock mass in response to release of load.
the Mississippi delta is a
FLUVIALLY dominated -BIRD FOOT DELTA
Who was Louis Aggassiz?
Father of glacial geology, the first guy to study it. Found that Europe was in an ice age and that there were no dinosaurs in the ice age.
What is the crest of a wave?
High point of a wave
What are the characteristics of a tropical climate?
High temperatures, average annual temp exceeds 20c. High rain, rainforests, large rivers, deeply weathered soils
What is wavelength?
Horizontal Distance Between Two Crests
What do geysers and thermal springs require to be created?
Hot rock bodies to heat groundwater Fractures system to transmit water Large supply of groundwater Geysers such as Old Faithful are the results of this process
What are continental glaciers?
Huge ice sheets, make up 95% of glacier ice Cover most of underlying terrain Occur mostly in antarctica and greenland
What is hydrolysis?
Hydrolysis occurs when silicate minerals react with water so that the mineral recombines with the water molecule to form a new mineral. For example, consider the mineral potassium feldspar. Potassium feldspar is a fairly common mineral and can be found in igneous, metamorphic and sedimentary rocks. When potassium feldspar reacts with slightly acidic water, it can be transformed into kaolinite
What are valley glaciers?
Ice streams that flow from mountain areas down into valleys. There are about 200,000 of these on earth and only make up about 1 or 2% of all ice on earth
how does a glacier erode it's surface?
Ice wedging happens first, and it is accompanied by plucking and abrasion.
What is scouring?
It is the process of abrasion, but only with a glacier.
What is Karst topography?
Karst topography is a landscape formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. This also leaves behind large hills of material that is not easily soluble
When there are floods, how will you know where the rivers are?
Levees
Sinkholes are a concern for residents whose dwellings are constructed atop _____.
Limestone
What is glacial loess?
Loess is fine-grained material that has been transported and deposited by the wind. The sediments come from glacial outwash plains, where glaciers deposit fine particles of silt and clay, or from desert areas that have little vegetation to anchor small particles.
What is backwash?
Long, offshore islands of sediment, trending parallel to the shore. Many develop from spits.
The first scientist to theorize the past presence of glaciers in Europe was _____.
Louis Agassiz
What is the trough of a wave?
Low point of the wave
What is the troposphere?
Lowest sphere. This is where we live. turbulent movement of air, wide variations of humidity and temperature. Temperature decreases with altitude.
What are the Milankovitch Cycles?
Milankovitch cycles are responsible for the rise and fall of glacial periods on the earth. These cycles include variations in the Earth's eccentricity, axial tilt, and precession
What is a mud flow?
Mixtures of water, mud, rock, and liquified soil flows downhill. Water lubricates mass of soil and rock and other debris, making it able to carry a lot. Boulders & building etc. may be carried
What are beaches made of?
Most Beach Sediment is Quarts Sand, as it is Resistant to Chemical Weathering
How does snow affect ice flow?
Movement of ice is dependent on snow accumulation because gravity pulls harder on heavier things. slope Accumulation is greatest at glacier head. Gravity pulls ice downward & outward As ice at the bottom of the glacier is pushed by the ice above it, it flows upward toward the snout because it has nowhere else to go
How does wind in the desert cause erosion?
Much like water erodes, wind carries sediment off the ground when there is no vegitation to protect it. Sand is transported near the earth, while dust is able to rise higher and is transported high in the air
The major dissolved constituent of the ocean is
NaCl (salt)
What is an aeolian system?
Open system driven by heat from the sun.
What are the human causes of desertification?
Overgrazing Cultivation Poor irrigation Destruction of vegetation
Which gases are unique to our solar system?
Oxygen, Water Vapor. Other planets have oxygen, but it is bound up with iron. Minor gasses like these absorb light and energy to retain heat
What is eccentricity?
Part of the Miankovitch cycle, Eccentricity is, simply, the shape of the Earth's orbit around the Sun.
What is precession?
Part of the Milankovitch cycle, Precession is the Earth's slow wobble as it spins on axis
What is axial tilt?
Part of the Milankovitch cycle, the inclination of the Earth's axis in relation to its plane of orbit around the Sun
What is the difference between physical weathering and chemical weathering?
Physical weathering is where an actual force breaks down a rock. Includes ice wedging and sheeting. In chemical weathering, the outside composition of the rock is changed because of its surroundings. Includes dissolution, oxydation, and hydrolosis.
what period of time was the last ice age?
Pleistocene
What kind of sea water is found in polar regions?
Polar = colder waters, low rainfall, & high salinity Dense surface waters in polar regions sinks
What is the difference between permeability and porousness?
Porous means the actual amount of pore space. This allows water to be inside a rock, but unless the pores are linked by fractures, the rock does not allow water to flow through it. This is permeability.
What is chemical weathering?
Proceeds by the removal or addition of chemical components to the minerals, changing the composition. Includes dissolution, hydrolisis, and oxydation
Which of the following minerals is most stable at Earth's surface?
Quartz
what mineral in granite is resistant to erosion?
Quartz
What are pluvial lakes?
Rain fed lakes developed in arid & semi-arid regions Formed in isolated basins Evidenced by remaining shoreline features and salt flats Lake Bonneville -> Great Salt Lake
Which part of the hydrological cycle starts the whole thing?
Rainfall
What is a landslide?
Rapid movement of large blocks of rock Slippage plane usually associated with: Bedding plane Joint plane Structural weakness Blocks generally degrade as they move
In general, the dominant erosional landforms in desert regions are developed by
Running Water
Lake Bonneville was the predecessor of
Salt Lake
How does the salinity of the ocean affect earth's climate?
Salt water has a higher heat capacity, which can be transferred to the overall climate.
How do grains move?
Saltation, creep, suspension
How are sinkholes formed?
Same way as caves, but they are still underground. With just a little bit of pressure, the top soil collapses.
What are sand sheets?
Sand sheets are flat, gently undulating plots of sand surfaced by grains that may be too large for saltation. Wind is generally lower in these areas, and rocks are generally larger
What happens when we build jetties to interfere with sand build up on the beach?
Sand will build up on one side of the beach and starve the other side
what rock would be the best to store nuclear waste in?
Shale
Where would you expect to see solifluction?
Siberia
What are transverse dunes?
Similar environment to Barchan dunes Greater availability of sand
What is soil?
Soil is earth material that is capable of sustaining rooted plant growth
What is the idea of soil structure?
Soils are more weathered at the top. Dissolved matter from the top of a soil column travels downward, and is deposited in the lower portions.
How is the atmosphere heated?
Solar radiation heats the atmosphere and so temperature varies widely with latitude and altitude/ the distance to the sun. It will lower the further north and south you go
How is the atmosphere circulating?
Solar radiation produces differential heating of the earth. Warm air naturally rises, and cool air naturally sinks and these moving air masses balance global temperature
The type of dune formed by winds blowing from at least three directions is a
Star Dune
How do valley glaciers change the valleys they go through?
Straighten, Deepen, Widen
What is the effect of longshore drift on structures?
Structures built like harbors are filled with sand because longshore drift brings it across no matter what.
Where are the most deserts?
Subtropical high-pressure belts.
In what season are beaches generally bigger?
Summer Beach is Wide -Waves are Smaller -Beach Builds Out -Bar is Eroded Winter Beach is Narrow -Waves are Larger -Beach is Eroded -Sand Stored Offshore
What is suspension caused by wind?
Suspension can only happen with very small particles like dust because they are completely suspended in the air and move freely. Dustbowl, Dust storms, etc
What temperatures are present in a desert climate?
T varies from very hot to very cold Slow rates of weathering Erosion by wind Evaporite deposits Low rainfall produces Dry soil (10" rain) Little vegetation (15%) No streams High evaporation
What controls the density of sea water?
Temperature and salinity. Cold water is denser than warm water. High salinity and denser than low salinity.
What is the amplitude of a wave?
The amplitude, a, of a wave is the distance from the centre line (or the still position) to the top of a crest or to the bottom of a trough. Be careful with this quantity - the centre line is not always given in a diagram. Amplitude is measured in metres (m).
What is an inclined aquifer?
The geologic conditions necessary for an artesian well are an inclined aquifer sandwiched between impervious rock layers above and below that trap water in it. Water enters the exposed edge of the aquifer at a high elevation and percolates downward through interconnected pore spaces. The water held in these spaces is under pressure because of the weight of water in the portion of the aquifer above it. If a well is drilled from the land surface through the overlying impervious layer into the aquifer, this pressure will cause the water to rise in the well. In areas where the slope of the aquifer is great enough, pressure will drive the water above ground level in a spectacular, permanent fountain.
What is the potentiometric surface?
The height to which water in a confined aquifer rises (if given the opportunity).
What is a berm?
The highest water mark for the previous year
What helps circulate the water in the ocean?
The ocean is driven by: Wind Variations in density Function of temperature and salinity. The ocean has a layered structure and the density varies with temperature.
What is hydrostatic pressure?
The pressure within a fluid at rest, exerted on a given point within the body of the fluid.
What is differential weathering?
The principle that rocks weather at different rates. the difference in degree of discoloration, disintegration, etc., of rocks of different kinds exposed to the same environment.
What is spheroidal weathering?
The principle that weathering happens most rapidly at the corners of a rock, so a once square rock becomes a circle.
What is snow metamorphism?
The process by which a snowflake becomes solid ice. The snowflake is first put under pressure, which melts the needles. After that, the water freezes into huge ice particles, which are called firn. From here, compaction pushes all the snowflakes together to create a solid block of ice. This is how snow falling on the top of a glacier becomes ice.
What is coastal straightening?
The process where waves erode any surfaces sticking out of the coast and slowly the coast becomes straight.
What is slope retreat?
The same thing as scarp retreat. Scarp retreat is a geological process through which the location of an escarpment changes over time. Typically the cliff is undermined, rocks fall and form a talus slope, the talus is chemically or mechanically weathered and then removed through water or wind erosion, and the process of undermining resumes. For river banks, this makes the bank wider.
What is gradient?
The steepness of the slope the stream is on. River runs faster the steeper the slope is and the higher up it is.
The thickest soils are produced by weathering in which type of climate?
The thickest soils are produced by weathering in which type of climate? Equatorial rain forests.
What happens when we dump trash on permeable sediment?
The trash sinks into the sediment until it reaches the water table
The ocean has two important layers. Which of the following is true of the upper layer as compared to the lower layer?
The upper layer is well-mixed and turbulent.
Where is the highest velocity in a river?
The very middle.
What is discharge?
The volume of water flowing past a given point in the river. Discharge will vary with time and weather conditions
What is the water table?
The water table defines the boundary below which all pore spaces are filled with water
What is the zone of aeration?
The zone above the water table that is dry
What are dunes shaped like?
They are assymetrical, Shallow upwind slope, 10-12 degrees Steep downwind slope, 33-34 degrees, angle of repose Sand transported up the windward face by saltation and surface creep, accumulates at crest Crest becomes unstable, sand avalanches down the slip face (cross bedding)
Why can't bedding planes carry water?
They are permeable but not porous
Why can't vesicles like basalt carry water?
They are porous, but not permeable
What are some influences of soil formation?
Topography-soil will not appear on cliffs becuase of gravity. The steeper the slope, the less soil you will find. Parent material-Qaurtzite makes bad soil, but shale is very good for planting Vegetation Time-some rocks weather quicker than others Climate-At the equator, the soil profile is very deep. The warmer and wetter it is, the better weathering will occur.
A geologist drills down into the continental crust and discovers this sequence of sedimentary rocks (top to bottom): glacial tillite-stream sediments-sand dunes-coal and shale. Assuming the changes were caused by the movement of the continent ("continental drift"), which way was the continent moving?
Toward a pole.
A geologist drills down into the continental crust and discovers this sequence of sedimentary rocks. Glacial tillite-Stream sediments-Sand dunes-Coal and shale. Assuming the changes were caused by the movement of the continent, which way was the continent moving?
Toward a pole.
What does water vapor do for the atmosphere?
Traps heat, reflects solar radiation. Water vapor is made from evaporation and precipitation
What is an unconfined aquifer? (water table aquifer)
Underground water that is connected to the whole surface through pores. It can be recharged simply by rainwater. You can dig anywhere and get water
What is till?
Unsorted rocks deposited by a glacier
What is wave height?
Vertical Distance Between Crest & Trough
What are horns of a valley?
Very peaks of mountains eroded by a glacier. formed when a sharp peak is surrounded by three or more cirques
What is ice wedging?
Water expands when it freezes, volume increases by 9%, pushing the rock more and more open. This is most effective in areas that freeze and unthaw alot.
What are the tributaries of a river?
Water flowing off the mountains to fill the river
Where can water be found under the earth's surface?
Water is found at some depth everywhere beneath the Earth's surface
What is the basal slip?
Water lubricates the bottom of the glacier and allows it to slip forward
How does water cause mass movement?
Water may act to increase or decrease cohesive strength Dry regolith or soil has little or no cohesion. Damp regolith or soil is sticky. Saturated regolith or soil flows easily
Which of the following statements is NOT a good description of ocean waves? Wave height is the vertical distance between crest and trough. Energy is imparted to waves by winds. Waves originate by the frictional action of wind on water. Water particles in waves move along at the same velocity as the wave. Wave refraction causes irregular distribution of energy along the coast.
Water particles in waves move along at the same velocity as the wave
Which minor gasses in the atmosphere absorb light and energy to retain heat?
Water vapor, CO2, Ozone, Methane
What happens when the energy of the wind is transferred to the ocean?
Wave height, length, and speed can change. These are all dependent on wind speed, length, and fetch.
What is weathering?
Weathering is the physical and/or chemical alteration of rocks and minerals where the lithosphere, hydrosphere, atmosphere, and biosphere meet
Globaly most deserts are found?
above 66 degrees north and south latitude (near the poles). near 30 degrees north and 30 degrees south latitude (subtropics).
feldspar is turned into clay through ____ ______
acid hydrolysis
Which of the following factors decreases the risk of mass movement?
adding vegetation to the side of a hill
artesian water question:
all of the above
What is a watershed?
an area or ridge of land that separates waters flowing to different rivers, basins, or seas.
What is a Graben?
an elongated block of the earth's crust lying between two faults and displaced downward relative to the blocks on either side, as in a rift valley.
What is fetch?
area of ocean or lake surface over which the wind blows in an essentially constant direction, thus generating waves. The term also is used as a synonym for fetch length, which is the horizontal distance over which wave-generating winds blow.
Ice wedging would be most effective in
areas where freezing and thawing occur many times a year
To qualify as a desert, a region must be _____.
arid, with less than 25 cm annual precipitation and very low relative humidity
What are the characteristics of polar climates?
average temperature below 10 C. cold as crap. Regions N & S of 60o latitude. less than 0C for most of the year. Low precipitation, often classified as deserts Low rates of weathering. glaciers
What is permeability?
capability of a rock to transmit fluid, high perm rocks include conglomerate, sandstone, basalt, limestone because of interconnected pore spaces or fractures
An important long-term factor determining whether glacial ice will form on the continents has likely been the proportion of which gas in the atmosphere?
carbon dioxide
antarctica was tropical because: (2 reasons)
change of continental position and climate change
Human manipulation of the groundwater system may result in
chemical changes. change in the water table level. salt water invasion. subsidence.
The path of movement of a water particle in a wave at sea is
circular
talus slopes are made of ______
coarse angular rock fragments
A talus accumulation consists largely of
coarse, angular rock fragments
What are tidal flats?
coastal wetlands that form when mud is deposited by tides or rivers. They are found in sheltered areas such as bays, bayous, lagoons, and estuaries.
Which of the following increases the risk of mass movement? adding a small amount of moisture to loose, dry sediment waves breaking before they reach sea cliffs flooding the sediment with water beyond saturation reducing the grade of the slope
flooding the sediment with water beyond saturation reducing the grade of the slope
The flat-lying area surrounding a river channel is termed the _____.
floodplain
As the velocity of flow decreases, _____.
flow tends to become more laminar the maximum flow velocity decreases suspended sediment starts to be deposited All of the above are correct.
the Mississippi river delta is a ______ ______ delta, also called a _____ ______ delta
fluvially dominated, bird foot
What is a yazoo stream?
formed parallel to the river because of backswamp
The principal difference between a lahar and a mudflow is the _____.
former mass contains pyroclastic debris from a volcanic eruption
Much carbon dioxide was removed from Earth's original atmosphere by
forming calcite (CaCO3) and other carbonate minerals in limestones.
drilling into the water table
forms a v, lowers the water table, salt water invasion
The prevailing wind direction at the time that these ancient sand dunes were deposited was
from the left.
u shape valleys come from
glaciers
moraine
glaciers are bulldozers
Saltation of sand involves _____.
grains hopping into the air, traveling for a short distance, and returning to the ground
A lag deposit, or desert pavement, is a concentration of
gravel-size particles left behind as wind selectively moves sand and dust from the surface.
The immediate cause of mass movements is _____.
gravity
ground water discharge
has several sources
levies form from flooding rivers, and
heavier particles fall first
if a river floods, you can still see the original outline because of
levees
Which of the following common rocks would be most susceptible to chemical weathering?
lilmestone
What type of rock is most susceptible to chemical weathering?
limestone
earth's atmosphere is no longer like venus because of
limestone
groundwater dissolution is common in:
limestone
rock most susceptible to chemical weathering
limestone
sinkholes are common in
limestone
karts topography: south china, mountains
limestone dissolution
barchan dunes have _____ sand
little
Which of the following is eolian in origin?
loess
What is an aridosol?
low latitude desert
During glacial epoch, global sea level is
lower because water is stored on the continents
Pumping vast quantities of water locally _____.
lowers the local water table, forming a cone-shaped depression
What is the water like at the bottom of the ocean?
mineral rich, cold, and very deep
faster the river velocity, the ____ ______ it carries and the ____ the grain size
more sediment, bigger
Cirques and horns are features associated with _____.
mountain glaciation
Within a meander, where is sediment most likely to be deposited?
on the inner banks of the meander
Which statement does NOT apply? Desertification occurs
only in small areas affecting at most a few million people of central Africa
A meander that is cut off to become completely isolated from the main channel, but which retains water, is a(n) _____.
oxbow lake
The minerals hematite and limonite result from the chemical weathering of iron-rich minerals like olivine or pyrite by what process?
oxidation
water table runs _______ to the ground, even if uneven
parallel
permafrost
permanently frozen ground
The ability of a porous solid to transmit a fluid is called
permeability
last ice age:
pleistocene
What is the El Niño affect?
upwelling stops because winds decreases, and the warm waters aren't as mineral rich, putting fisherman out of work because the fish can't eat the plankton.
rock glacier
usually at the head of glacial valleys. they work just like a glacier, but are rocks
Sediments deposited directly by glaciers as they melt are characterized by _____.
very poor sorting
What angles can be found in subaqueous crossbedding
very shallow angles
lahar
volcanic debris flow
What is capillary water?
water that remains in the soil after gravitational water is drained out, that is subject to the laws of capillary movement, and that is in the form of a film around the soil grains
What is humidity?
water vapor
the greenhouse effect
water vapor warms the earth
The horizontal distance between two successive waves' crests is called
wave length
This photograph of a shoreline in Washington shows a
wave-cut platform.
What kind of sediments are best for permeability?
well rounded, well sorted, and those with no cement
Groundwater discharge occurs at
wells geysers springs streams
stream piracy
when a river intersects with another one and changes headwaters
artesian water
when the water is under pressure
backswamp
where the floodplain is lower than the river, so it is swampy
Excessive pumping of a well
will create a cone of depression may cause saltwater invasion in coastal areas may cause adjacent wells to become dry will lower the water table locally
Ordinary ocean waves derive their energy from
winds
What are the different parts of a sand dune?
windward face, slip face, cross bedding
long shore drift comes in obliquely and leaves perpendicularly, creating a _________ pattern
zig-zag
zone below the water table is the
zone of saturation