Final Exam Study Guide Flashcards
What are the different types of tectonic stress, their resulting strain, and the associated folding/faults?
- Tension tectonic stress -> stretching strain -> thinning surface -> normal fault
- Compression tectonic stress -> shortening strain -> folding surface -> reverse fault
- Shear tectonic stress -> shearing stress -> horizontal bending surface -> transform/strike-slip fault
What is the difference between an anticline and a syncline?
Anticline is where the crust folds up and syncline is where the crust folds down
Describe a normal fault
Hanging wall drops and foot wall rises up, creating mountains and basins/ranges (graben/horst); fault plane dips at an angle
Describe a reverse fault
Hanging wall rises and folding occurs; fault plane dips at an angle
Describe a strike-slip fault and the difference between left and right lateral
Lateral slide relative to areas across the fault with little to no vertical displacement; named for the side that moves toward you
-Left-lateral – When standing on one side of the fault, the opposite side moves to the left
-Right-lateral – When standing on one side of the fault, the opposite side moves to the right
What landscapes do normal, reverse, and strike-slip faults form?
-Normal - Fault block mountains (like the Tetons)
-Reverse - Contribute to mountain building
-Strike-slip - Offset streams, valleys, and other existing landscapes
What is horst and graben topography?
Horst - Upward-faulted blocks (range) landscapes
Graben - Downward faulted blocks (basin) landscapes
Interplate tectonics influence on earthquakes?
Between plate interactions, like divergent and convergent boundaries, which have more frequent earthquakes which are typically larger
Intraplate tectonics influence on earthquakes?
Within plate interiors, due to internal stress or reactivation of ancient faults, where which earthquakes are less frequent and can be large (but less common)
What is the focus of an earthquake?
The location below Earth’s surface where the motion of seismic waves that cause an earthquake begins; also called the hypocenter
What is the epicenter of an earthquake?
The location on Earth’s surface directly above the focus of an earthquake
What are asperities in earthquakes?
Irregularities along fault lines that serve as catching points, allowing the buildup of strain
Describe fault asperities in detail
Irregularities along fault that serve as catching points, allowing the buildup of strain, which a few of will break initially causing foreshocks when the strain becomes too great. This places additional strain on the remaining asperities, causing a mass breakage that manifests as an earthquake. Some remaining asperities may break afterwards causing aftershocks
What is liquefaction?
When waterlogged sediment loses structural integrity due to shaking from earthquakes
What is induced seismicity and what are its causes?
When the injection and extraction of fluids from the ground strains the pores and fractures in rocks leading to human caused earthquakes. The extraction of groundwater is one of its causes
What is the difference between weathering and erosion?
Weathering is the he breakdown of a solid mass into smaller particles, while erosion is the transport of weathered particles to another location by gravity, wind, ice, water, etc.
What is the difference between physical and chemical weathering?
Physical Weathering, aka mechanical weathering, is the breakdown of rock without chemical alteration, while chemical weathering is Breakdown of the constituent minerals in rock in the presence of water, which causes a change to the chemical composition of the rock and increases with warmer temperatures and increasing precipitation
Describe frost action/frost wedging
Type of physical weathering where when water freezes, its volume expands, creating a powerful mechanical force that can overcome the tensional strength of rock. Repeated freezing (expanding) and thawing (contracting) of water is frost action, or freeze-thaw, which breaks rocks apart through the process called frost wedging
Describe salt-crystal growth
Type of physical weathering where as the water on the surface of rocks evaporates, dissolved minerals in the water grow crystals – crystallization. Over time, as the crystals grow and enlarge, they exert a force to spread apart individual mineral grains and begin breaking up the rock. Often occurs in arid environments
Describe exfoliation (pressure-release jointing)
Type of physical weathering where rocks brought near the surface are exposed to lower pressure and expand, and layers of rock peel off in slabs or plate (sheeting). Creates arch and dome-shapes features
Describe hydrolysis
Type of chemical weathering where water changes the chemical composition of minerals in rock, making them less resistant to weathering. Common in granites and gneiss; makes granite appear etched, corroded, and softened
Describe oxidation
Type of chemical weathering where oxygen dissolved in water oxidizes (combines with) certain metallic elements to form oxides; most familiar is the “rusting” of iron in a rock or soil (Ultisols, Oxisols), which produces a reddish-brown stain of iron oxide
Describe dissolution of carbonates
Type of chemical weathering where water vapor + CO2 = acidic rainwater; certain minerals are highly reactive with acidic water and dissolve in solution and erode away. Common with limestone and marble
What is spheroidal weathering?
A chemical weathering process in which the sharp edges and corners of boulders and rocks are weathered in thin plates that create a rounded, spheroidal formWhat is spheroidal weathering?
Why do Georgia’s soils consist of red clays?
The warm, moist climate leads to oxidation, which produces red color, and hydrolysis, which produces clays
In what environments does mechanical weathering dominate? Chemical weathering?
-Chemical weathering – Common in warm, wet environments
-Physical weathering – Common in cold, moist environments
What are driving forces that govern slope stability?
Gravity, water pressure, seismic shaking, windthrow
What are resisting elements that govern slop stability?
Frictional resistance, cohesion, root strength
What factors influence slope stability and what changes in this increase the chance of failure?
Material strength/cohesion, water content, and slope changes. Removing vegetation, weathering, shaking, increasing water content, and increasing slope can all decrease stability by either decreasing resisting elements or increasing driving elements
Describe the type of mass movement of rockfall?
Dry, fast, individual rocks, forms a talus slope
Describe the type of mass movement of soil creep?
Dry, slow transport of material downslope, particle by particle; can be caused by freeze-thaw cycles of moistness and dryness cycles
Describe the type of mass movement of landslides?
Sudden rapid movement of a cohesive mass that is not saturated with moisture
Describe the type of mass movement of debris avalanches?
Fast-moving, unconsolidated, larger material mass wasting event with high moisture, often caused by heavy rains
Describe the type of mass movement of mudflows?
Fast-moving, unconsolidated, smaller sediment and more water mass wasting event, often caused by heavy rains
What is a talus slope and what mass movement type is it associated with?
Formed by angular rock fragments that cascade down a slope along the base of a mountain; poorly sorted, cone-shaped deposits and associated with rockfall (dry, fast mass movement)
What is karst topography? In what environments does it occur (rock type, climate)?
Topography formed in a region of chemically weathered limestone with poorly developed surface drainage, where the surface appears pitted and bumpy and caverns may appear below the surface
What type of weathering dominates in karst landscapes?
Chemical weathering, specifically the dissolution of carbonates
What are sinkholes and how do they form?
The weathering of limestone landscapes creates sinkholes, formed in circular depressions. Process: Sediments (overburden – mostly clay) spall into a cavity; As spalling continues, the cohesive covering sediments form a structural arch; The cavity migrates upward by progressive roof collapse; The cavity eventually breaches the ground surface, creating sudden and dramatic
What are karst valleys and how do they form?
Valleys part of karst topography which are created through the chemical weathering process of dissolution of, so often are found in areas with soluble rocks like limestone, etc. They may have steep walls and uneven floors due to underground drainage, caves, or sinkholes
What are disappearing streams and how do they form?
Surface streams that abruptly vanish into the ground, often through sinkhole or fissures, common in regions with karst topography. The stream will enter the existing underground system and continue its path below the surface, before later often reemerging
What is tower karst and how does it form?
A type of karst landscape characterized through tall, steep-sided limestone towers that rise from the ground, which form through continuous chemical weathering and erosion in tropical regions with high rainfall, as water dissolves limestone along its fractures
How do stalactites and stalagmites form and what’s the difference?
Both are formed as the calcium carbonates that was dissolved into an aqueous solution elsewhere then precipitates out upon evaporation of the water as it drips in the cave.
-Stalactites - Grow down from the ceiling (hold on tight to not fall to the ground)
-Stalagmites – Build up from the ground (might grow up to the ceiling)
What is a watershed?
Terrain that contributes water to a stream also called a drainage basin or catchment, which is the area of landscape that drains to a given point in a river system and exist at many scales
What is a drainage divide?
Ridges that separate watersheds and mark drainage basin’s boundaries
Describe dendritic drainage pattern
Resembles the branches of a tree, with randomly branching pattern and no dominant alignment of channels
Describe trellis drainage pattern
Resembles a garden trellis, with parallel mainstreams and short tributaries joining at nearly right angles, and common in regions of folded or tilted rock layers
Describe radial drainage pattern
Streams radiate outward in all directions from a central high point, like spokes on a wheel, and it develops around this central elevated feature
Describe parallel drainage pattern
Nearly parallel streams running in the same direction with very little branching, common in areas with consistent directional slope and elongated topography
What is drainage density and what factors affect it?
Drainage density = total length of all stream channels in the basin / area of the basin. It’s determined by climate (higher precipitation areas will have higher drainage densities), landscape characteristics (steep slopes and low infiltration rate materials will lead to higher drainage densities), and surface material (silty clay = high runoff potential = high drainage density)
Describe flash hydrographs
Steep rising and rapid peak discharge, with a short lag time, often caused by thunderstorm or similar events and increased as well by urbanization and wildfires
Describe subdued hydrographs
Gentle, gradual rising and lower peak discharge, with a long lag time, often caused by snowmelt or prolonged, less intense rainfall
What is sinuosity and how is it calculated?
Measures how meandery a stream is, with high meaning very and low meaning not very. Calculated as Sinuosity = stream length (length along channel) / valley length (aka straight-line length)
What is bed-load transport, and what’s the difference between saltation and traction?
The transport of coarser materials in streams, where saltation is bounding and traction is sliding
What is suspended load?
Fine-grained particles held in stream until stream velocity decreases
What is dissolved load?
Materials carried in chemical solution in a stream, derived from minerals such as limestone and dolomite or from soluble salts
What is sediment transport capacity and how is it related t discharge or velocity?
The amount of sediment that a stream can carry. Mean velocity increases with greater discharge at a given point along a stream, and as discharge and velocity increase, so does sediment transport capacity
What is sediment load?
The total amount of sediment transported by a river or stream, which includes materials such as soil, sand, gravel, and dissolved substances
Describe aggradation?
The general building of a land surface because of deposition of material, which occurs when the sediment load of a stream exceeds its capacity to carry it, the stream channel accumulates material through this process
Describe degradation?
The process occurring when sediment is eroded along a stream, causing channel incision, which occurs when sediment load is lower than its capacity
What is an oxbow (lake) and how is it formed?
A lake that was formerly part of the channel of a meandering stream; isolated when a stream eroded its outer bank, forming a cutoff through the neck of the looping meander
What is a point bar and where in a meander do they occur?
In a stream, the inner portion of a meander, where sediment fill is redeposited as stream velocity decreases
What is a cutbank and where on a meandering river do they occur?
In a stream, a steep bank formed along the outer portion of a meandering stream; produced by lateral erosive action of a stream; area of maximum stream velocity; sometimes called an undercut bank
What is a braided river and in what conditions do they form?
A stream carrying a high sediment load that becomes a maze of interconnected channels; occurs with a reduction of discharge that reduces a stream’s transporting ability or with an increase in sediment load
Under what conditions do meandering rivers form?
In conditions where water discharge is consistent and sediment supply is lower
Explain the mass balance principles of how glaciers form?
Accumulation zone is where buildup occurs at upper area of glacier; ablation zone is where loss of glacial ice occurs at lower area, with a downhill flow between the two
In which conditions do glaciers advance and recede?
-Cold, wet periods -> positive mass balance where accumulation > ablation and glacier grows and advances (creeps downslope)
-Warm, dry periods -> negative mass balances where ablation > accumulation and glacier shrinks and recedes (moves upslope)
What is the ELA?
The Equilibrium Line Altitude on a glacier where inputs = outputs
What is the firn line?
The line on a glacier above which snow survives the summer
What is a glacial terminus?
The end of the glacier, which can reflect the overall mass balance based on its movement
How can you tell if a glacier is advancing?
The terminus moves forward (downslope) and the glacier appears to grow in length and thickness, while the mass balance is positive, indicating accumulation > ablation and there is a net gain in glacial mass over time
How can you tell if a glacier is receding?
The terminus moves backwards (retreats upslope) and the glacier appears to shrink, with thinning ice and a reduction in its extent, so the mass balance is negative, with ablation > accumulation, indicating a net loss in glacial mass over time
What is latitude?
The lines that run East-West, are parallel and are measured North-South, starting at 0 degrees (the Equator) and ending at 90 degrees (the N and S Pole)
What is longitude?
The lines that run North-South, are non-parallel and are measured East-West, starting at 0 degrees (the Prime Meridian) and ending at 180 degrees (the International Date Line)
What are parallels?
A line, parallel to the equator, that designates an angle of latitude
What are meridians?
A line designating an angle of latitude
What is a positive feedback loop?
A mechanism that tends to amplify or encourage responses in a system. It induces progressively greater changes in other parts of the system; “snowball effect”
What is a negative feedback loop?
A mechanism that tends to slow or reduce responses in a system and promotes self-regulation of the system. This tends to keep the system in its original condition, inhibiting change
What is axial tilt?
Earth is tilted 23.5 degrees off of vertical due to a collision with a large body, which is perpendicular to the plane of the ecliptic (plane of Earth’s orbit around the sun)
What is rotation?
The spinning of the Earth on its axis. It makes 1 turn about every 24 hours, defining day and night, which causes daily (diurnal) rhythms (light, temperature, humidity, human and animal behavior), affects wind and ocean currents (Coriolis Force), and affects Earth’s shape
What is revolution?
The movement of Earth around the Sun (elliptical orbit), where 1 revolution is 365.2 days, which is NOT a reason for the seasons
What’s the difference between the aphelion and the perihelion?
-Aphelion – Furthest point away from the Sun on July 3rd, at about 152 million k-Perihelion – Closest point to the Sun on Jan 3, at about 147 million km
What does sphericity (curvature) do?
-Beam spreading – Insolation is spread over a greater area near the poles since the sun angles are less direct, so more intense at the equator
-Beam depletion – Energy from the sun has to pass through more of the atmosphere near the poles due to less direct sun angles and longer path through the atmosphere, which weakens insolation at the surface
What causes the seasons?
Axial tilt, revolution, and curvature of the Earth all combine to produce an annual cycle in both intensity (amount of beam spreading) and duration (daylength) of insolation
How does daylength vary with season at varying latitudes?
Due to the Earth’s axial tilt, different latitudes vary in the amount of daylight hours they receive depending on how much each location is tilted towards the sun
Describe the December Solstice?
The time when the Sun’s declination is at the Tropic of Cancer, at 23.5 degrees S latitude, on December 21-22 each year. The day is 24 hours long south of the Antarctic Circle and the night is 24 hours long north of the Arctic Circle
Describe the March Equinox?
The time around March 20-21 when the Sun’s declination cross the equator (0 degrees latitude) and all locations on Earth experience equal day and night
Describe the June Solstice?
The time when the Sun’s declination is at the Tropic of Cancer, at 23.5 degrees N latitude, on June 20-21 each year. The night is 24 hours long south of the Antarctic Circle, and the day is 24 hours long north of the Arctic Circle
Describe the September Equinox?
The time around September 22-23 when the Sun’s declination crosses the Equator (0 degrees latitude) and all places on Earth experience days and nights of equal length
What is the order of the atmospheric vertical temperature profile layers?
Troposphere, tropopause, stratosphere, stratopause, mesosphere, mesopause, thermosphere, thermopause
Describe the atmospherical vertical temperature profile and how temp changes throughout?
-Troposphere - Somewhat higher temp but decreases with height
-Tropopause - At -57 degrees C
-Stratosphere - Higher temp which increases with height
-Stratopause - 0 degrees C at 50 km mark
-Mesosphere - Decreasing temp with altitude
-Mesopause - Coldest part of atmosphere (~80 degrees C)
-Thermosphere - Temp increases with altitude, highest temps but not “hot”
What is the heat source of each layer of the atmospheric temperature profile?
-Troposphere – Heat source is radiation absorbed at the surface, which increases temp but it decreases with altitude—Stratosphere – Heat source is absorption of UV rays by ozone layer which causes increase in temp
-Mesosphere – Decreasing temp with altitude because heat source is mainly the stratosphere located below
-Thermosphere – Heat source is solar radiation from the powerful Sun’s rays, which causes temp increase
How does pressure (density) vary with height in atmosphere?
Pressure and density decrease with altitude due to less air molecules being present because gravity pulls them closer to Earth’s surface
What is radiation and where does it come from (i.e., what objects emit radiation)?
Radiation is energy that travels through space in the form of waves or particles (coming from unstable atoms attempting to become more stable). All objects emit radiation, but the type and amount of radiation is a function of the temperature of the source
What are wavelength and frequency, how do they relate, and how do they relate to energy?
Two of ways of describing the same phenomenon, electromagnetic wave motion. Fewer long wavelengths pass a point in a unit of time, so they are lower frequency; more short wavelengths pass a given point during a unit of time, so they are higher frequency (inverse relationship). As wavelength increases, energy decreases (inverse), but as frequency increases, energy also increases (direct)
What are the different classes of EM radiation (UV, Infrared, etc.) and what are their relative locations on the EM spectrum?
- Gamma
- X-ray
- UV
- Visible
- Infrared
- Microwave
- Radio
What is the Stefan Boltzmann Law?
E = σ x T4, which means the hotter an object, the more radiation it emits
What is Wein’s Law?
λpeak = 2898 / T, which means the hotter an object, the shorter the wavelength that is most abundantly emitted by that object
What is conduction?
The slow molecule-to-molecule transfer of heat through a medium, from warmer to cooler portions
What is convection?
Transfer of heat from one place to another through the physical movement of air; involves a strong vertical motion
What is radiation?
The transfer of heat in electromagnetic waves
What is net radiation and how is it calculated?
Energy in minus energy out, which is calculated as Rnet = SWin – Swout + Lwin – Lwout
How does net radiation relate to temperature?
-If Rnet > 0, temp increases
-If Rnet < 0, temp decreases
How does Earth’s energy budget (i.e., net radiation) vary with latitude and why?
Heating is not uniform; so at the poles, more energy is lost than gained and at the equator, more energy is gained than lost. Overall a surplus of energy at the equator and a deficit at the poles
What is the greenhouse effect?
A natural phenomena where SW radiation transmits freely through atmosphere, while greenhouse gases absorb LW radiation emitted by the Earth, then re-emit some of that longwave radiation back toward the surface which holds in heat. Without it, Earth would be 0 degrees F
What are the principle controls on temperature (4)?
Latitude, elevation, continentality/marine effect, and cloud cover
Describe latitude’s effect on temperature?
Higher (more poleward) latitudes experience cooler overall temperatures and a larger annual temperature range (and vice versa)
Describe elevation’s effect on temperature?
Temperatures decrease and daily temperature ranges increase with increasing altitude because thin air has a low ability to absorb and radiate sensible heat
Describe the continentality/marine effect’s effect on temperature?
-Continental effect refers to areas less affected by the sea and therefore having a greater range between maximum and minimum on both a daily and yearly basis-The term marine effect describes locations that exhibit the moderating influences of the ocean, usually along coastlines or on islands; so a smaller temperature range with overall cooler summers and warmer winters than inland areas
Describe cloud cover’s effect on temperature?
Under overcast skies – Reflection of SW and lower daily temperature, absorption and reemission of LW and higher daily minimum temperature; overall reduced daily temperature range
Define relative humidity?
The amount of water vapor relative to max possible, which is most commonly referenced
Define specific humidity?
[Grams of water vapor/kg of total air] = [g/kg], which increases via evaporation and decreases via condensation
How are relative and specific humidity related?
As specific humidity increases, so does relative humidity if temperature is constant (although depends on temperature because warmer air can hold more moisture)
Define SSH?
Max water vapor at a given air temperature
How does SSH relate to temperature?
-Increasing temp – SSH increases because the capacity of air to hold water vapor expands, but actual water vapor content (specific humidity) might remain constant; relative humidity decreases because the air’s capacity to hold moisture increases, making the same amount of water vapor a smaller proportion of the capacity-Decreasing temp – SSH decreases because cooler air holds less water vapor, so if specific humidity remains constant, relative humidity increases because the air’s capacity to hold moisture is reduced, making the same amount of water vapor a greater proportion of the capacity
What is true at saturation?
RH = 100%, Tair (air temp) = Td (dewpoint temp), and SH = SSH
What is the difference between adiabatic and diabatic heating / cooling.
-Adiabatic – Temperature changes occur without the transfer of heat to or from the surrounding environment due to changes in pressure
-Diabatic – Temperature changes occur with the transfer of heat to or from the surrounding environment due to energy exchanges through processes like radiation, convection, or latent heat transfer
What is the pressure gradient force?
The force that results from differences in air pressure across a given distance, which initiates air motion and air moves HIGH to LOW pressure; PGF = Change in Pressure / Change in Distance
How does the Coriolis force influence the wind in the northern hemisphere? Southern hemisphere?
Caused by Earth’s rotation and causes an apparent deflection. In the Northern Hemisphere, deflection to the right; in the Southern Hemisphere, deflection to the left. Zero at equator; maximum near poles; only affects large-scale motions and air already in motion (can’t initiate); proportional to wind speed
How does air circulate in high vs low-pressure systems in the Northern Hemisphere?
-High-pressure – Air moves outward, clockwise, and down due to the Coriolis effect
-Low-pressure – Air moves inward, counterclockwise, and upward due to the Coriolis effect
Vertical motion and weather associated with high-pressure systems?
Air is caused to move outward from the high-pressure area, creating an area of descending air. Associated with clear, calm weather because the descending air inhibits cloud formation and vertical air movement
Vertical motion and weather associated with low-pressure systems?
Air is forced upward from the low-pressure area, leading to rising air that can cool and condense, resulting in cloud formation and often stormy weather
