ULTIMATE QUIZLET PLANET EARTH

Saltation

"hopping" grains because size is too large for continuous suspension.

saltation

"hopping" grains because size is too large for continuous suspension. Typically falling grains dislodge more grains (transfer of kinetic energy)

cliff retreat on all sides produces?

"island of rocks" - inselbergs

Viscous

(fluids) y=x as linear regression of stress v. strain

thunderstorms

- local episode of intense rain + strong winds & lightening, occur when warm, moist air meets cold, dry air (mid-USA during the summer), convective lifting driven by solar radiation or orographic lifting, latent heat of condensation enhances the lifting eventually allowing anvil clouds to form., hail forms if updrafts are strong enough to take water to levels where it freezes, Precipitation indicates storm is in the "mature stage", as falling rain pulls air down with it creating strong downdrafts. Interaction of updrafts and downdrafts produces strong, gusty winds. Once downdrafts predominate, storm dissipates.

how do wave cyclones form?

- when air on one side of the cold front shears sideways past air on the other side., this warps the face of the front into the shape of a wave, warm air starts to move north and up and over the cold air mass, creating a warm front., Cold air circles around and starts to move south and downward, pushing the cold front forward., The two fronts meet in a "V", the point of which lies near the center of the low-pressure mass, forming a huge spiral mass of clouds., The cold front of a wave cyclone moves faster than the warm front, so the warm front becomes occluded and the cyclone dies out.

sanitary landfill

-A layer of compacted trash is covered by a layer of earth at least once a day, The soil keeps out vermin and confines the trash., Usually sited in abandoned gravel pits or surface mines., When full, a thick layer of earth is put on top and the area given over to other uses (parks, golf courses, car parks, etc.).

groundwater quality

-Dissolved Mg2+ and Ca2+ = hard water: scale on pipes and appliances, soap won't lather. Pipes can become clogged., Fe2+ also dissolves., H2S = "rotten eggs"., Arsenic from Arsenopyrite (FeAsS).

stratospheric ozone depletion

-Ozone (O3) is an important component of the stratosphere because it blocks harmful ultraviolet (UV) radiation. Chlorofluorocarbons (CFCs) catalyze destruction of ozone., A huge area of depleted ozone (termed an ozone hole although ozone is still present) has been measured in polar regions.

long-term causes of ice ages

-Plate Tectonics: drift to high latitudes;, Continents must be well above sea level; Ocean currents must be restricted - warm water doesn't move far from the equator, Greenhouse gas (e.g., CO2): input to atmosphere (from volcanoes, fossil fuel burning); output from atmosphere (plants; coal/oil formation, shells, limestone deposition, etc.).

how to prevent infiltrating water from accumulating in the landfill and eventually spilling over the liner:

-Use low-permeability materials above and below landfill to minimize this., Pump out leachate and treat before disposal., Plants growing on a finished landfill may uptake toxic chemicals - warning against using the site for farming.

when does stream velocity drop below settling velocity?

-a stream enters a standing body of water, the channel widens, the stream gradient decreases, discharge decreases due to evaporation, infiltration, or removal for irrigation, obstructions

supercontinent cycle

-all continents are joined in one land mass. Has happened ~4 times over the last 3 billion years, takes a few hundred million years to complete because plates move at 1-15 cm per year, land never rearranges exactly the same through two cycles

karst

-area of limestone underlaying the soil - lots of sinkholes defined by circular lakes., Sinkholes occur in limestone areas that have a lot of water, which can dissolve the rock., Surface streams uncommon and may disappear. Surface expression may not reflect the magnitude of cavern development beneath.

castle-bergs / pinnacle-bergs

-blocks that calve off valley glaciers are pointed, blocks that calve off continental ice sheets are tabular and can be >100 km across

consequences of sea-level changes

-continental shelves partly exposed, Britain connected to Europe, base level of streams lowered (more erosion), Bering Sea land bridge formed; Russia connected to USA

outwards

-do not retreat by moving uphill

stages that karst landscapes form in:

-establishment of a water table in limestone, formation of a cave network: after the water table is established, dissolution begins, a drop in water table level, roof collapse

features of desert land surfaces

-exposed bedrock, accumulated clasts, unweathered sediment, precipitated salt, windblown sand

erosion due to glaciers results in:

-fine rock powder called "rock flour", polished rock surface scraped clean of soil and vegetation

flood plain

-flat area adjacent to the river channel that periodically flows, flat area outside of the channel. velocity drops once water has spilled out of the channel and deposits fine sediments (muds/silts)

how does ice form?

-from snow that forms in layers (sedimentary rock) and then recrystallizes into ice (metamorphic rock)

what does lightening create?

-heat (8,000-33,000 Celsius), causes surrounding air to rapidly expand, produces an explosion

where do artesian springs form?

-if the ground surface intersects a natural fracture that taps a confined aquifer and the pressure is sufficient to allow water to get to the surface, where a perched water table intersects the side of a hill

gas pollutants from sanitary landfills

-initially aerobic decay (trapped air) - CO2 and SO2. Changes to anaerobic (CH4 & H2S)., These gases may percolate through the soil and naturally vent, but want to keep them in - CH4 is a greenhouse gas and both CH4 and H2S, if in high enough concentration, may cause asphyxiation., If kept in, quantity of CH4 produced could be used commercially. If not, it is burnt off.

groundwater usage problems

-lowering the water table, reversing groundwater flow, saline intrusion, pore collapse and land subsidence, contamination

suspended water is held by

-molecular attraction between water and rock, mutual attraction between water molecules

role of greenhouse gases

-most of the incoming visible light from the Sun penetrates the atmosphere and warms Earth's surface, this absorbed energy is released from the surface as infrared (thermal) energy, certain gases (H2O, CO2, CH4, NO2 and O3) in Earth's atmosphere absorb thermal energy and re-radiate it, warming the lower atmosphere

characteristics of deserts

-no permanent surface water, <15% vegetation cover, arid nature produced by high and low temperatures as well as orographic lifting, little chemical weathering: bare bedrock, wind blown sand, cobbles, salt precipitation

other factors of ice age theories:

-positive feedback mechanisms that enhance the processes that cause them, changing albedo, interrupting the global heat conveyor, biological controls on CO2 Production/consumption

groundwater contamination

-rocks are good filters - suspended solids can be removed and clays can act as exchange surfaces to remove pollutants, groundwater contains dissolved materials that can be toxic or non-toxic but unpleasant, some organic materials don't mix with water but get pushed through the system, bacteria from septic systems can go through an aquifer

roche moutonnee

-rounded rock steps, can form as isolated hills because of difference in rock strength (Edinburgh Castle)

shape of a delta is dominated by the river and is a function of:

-sediment supply, shifting of river mouth, waves and currents in the body of water, tides

consequences of climate change

-shift in climate belts and vegetation zones, the amount of precipitation across North America will be different a hundred years from now (drier in summers, wetter in winters), warming will modify the climate latitude of the states, increase number of threatening heat waves, stronger storms, greater evaporation, greater differential pressures, more vigorous hydrologic cycle, rise in sea level due to water added from melting glaciers, ice shelves, ice caps

lightening

-speculation: rubbing of water & air molecules creates positively charge ice and H that drift to the top of a cloud. Negatively charged OH- sink to the base, creating a zone of positive charge on the ground., As air is a good insulator, the charge separation can become very large, until a lightening flash jumps across the gap. This begins when electrons incrementally leak from the negatively charged cloud base to the ground creating a conductive path.

conditions under which springs form:

-where the ground surface intersects the water table (valley sides), where the water percolating downward intersects an impermeable layer and runs along the top of it until it intersects the surface, where the aquifer intersects a hill side, where a network of interconnected fractures allows channeling of groundwater to the surface, where flowing groundwater intersects a steeply dipping impermeable layer (can be caused by faulting)

variability of tides

0.1-15m

2 ways precipitation occurs

1) collision & coalescence, 2) Bergeron Process

eolian landscape features

1) dune-scale cross-bedding, 2) sediments are extremely well-sorted, 3) sediment grain composition dominated by quartz, 4) Frosted quartz grains due to abrasion and chemical etching, 5) terrestrial fossils

conditions for glacier formation

1) local climate - cold enough for snow to remain year round, 2) snowfall is sufficient for accumulation, 3) surface is gentle so snow does not slide away (glaciers do not exist on slopes > 30 degrees - avalanches)

theories of desert pavement formation:

1) they are a lag deposit, 2) product of sheetwash erosion, 3) wetting of soils causes clays to expand pushing larger stones upward. Drying shrinks the clays and the stones settle down fitting together tightly, 4) bubbles formed by bacteria metabolism gradually buoy stones upward, 5) wind blown fine sediment is deposited between the stones and washes down. The stones were never buried, but this is a way to increase the thickness of the finer layer between them

what is dune shape dependent upon

1) velocity and persistence of wind, 2) abundance of sand, 3) presence of vegetation

Factors of mass movement

1. Type of material involved 2. Velocity of movement, 3. Character of movement, 4. Environment

evolution of a rocky coast

1. flooding of coast -> irregular coast, 2. erosion of cliffs/headlands, 3. straightening of beach

glaciers have covered up to ____ of Earth's surface in the recent geologic past

1/3

on a global basis, how much glacial ice melts every year?

100 cubic miles (400 cm^3)

arid regions

10s of meters below surface

1. During abrupt, heavy rains (water falls faster than it can infiltrate);

2. After long periods of continuous rain (ground is saturated);

Groundwater accounts for _______% of all the liquid freshwater on Earth

2/3

sea-level changes up to _______ during the past 500 Ma

300 m

3. Heavy snows melt after winter;

4. When an artificial or natural dam breaks.

depth of the abyssal plains

4000-6000 meters

_____ % of the atmosphere lies below 5.6 km

50%

ionosphere

60-400 km (mostly Exosphere) where solar radiation strips N and O of their electrons. This layer reflects radio transmissions (short-wave). The aurora boreallis (northern) and aurora australis (southern) form here

composition of the atmosphere

78% nitrogen, 21% oxygen, 1% Ar, CO2, CH4, O3

__ % of the atmosphere lies below 16 km

90%

____ % of the atmosphere lies below 100 km

99.99

aerosols

<1 micro-meter particles that can remain suspended in air. Sea salt, volcanic ash, clay, soot, pollen, water, & acid droplets

Thermosphere

<1% of the atmosphere resides here, but gases absorb short-wavelength solar radiation

speed of a tropical depression

>38 mph

speed of a hurricane

>74 mph

What feature is found between two glacial valleys?

A arete

seawall

A barrier constructed to prevent waves from reaching the area behind the wall. Its purpose is to defend property from the force of breaking waves.

longitudinal profile

A cross section of a stream channel along its descending course from the head to the mouth.

badlands topography

A landscape with steeper slopes, sparse vegetation, thin soils, and extensive stream network.

What is an Esker?

A long sinuous ridge of water-deposited sediment

what has seismic profiling provided?

A much better understanding of the oceanic crust

jetties

A pair of structures extending into the ocean at the entrance to a harbor or river that are built for the purpose of protection against storm waves and sediment deposition.

What was the cause of the ozone hole over Antarctica?

A. Atmospheric release of chloro-fluorocarbons

subsidence of deltas

Abandoned delta lobes, starved of sediment, slowly compact, dewater, and subside. Abandoned delta lobes are eventually submerged.

Vertical stress

Acts on a horizontal plane at shallow depth, assuming a consistent body of rock above point

How do contaminants move within the saturated zone?

Advection and hydrodynamic dispersion

Rocks formed during orogeny

All types: magmatism promoted by subduction. Metamorphism promoted by temperature and pressure. Sedimentary rocks formed through erosion of uplifted arc/mountain range.

Strain

Amount of deformation

Porosity

Amount of void space

Plunge

Angle between line and horizontal (usually for fold/structure)

Strike

Angle between true north and horizontal line contained in any feature.

Q1. What percentage of the Earth's land surface do deserts cover?

Answer: 25

Q3. Deserts experience less than ____mm of rainfall a year

Answer: 250

Q2. What temperature can deserts reach in a day (degrees Celcius)?

Answer: 50

Q10. Australia is the second driest continent, which is the first?

Answer: Antartcia

Q3. What makes the gyres in the northern hemisphere circulate clockwise:

Answer: Coriolis Effect

Q6. What is the outermost layer of the atmosphere called?

Answer: Exosphere

Q6. The warm water current that goes up eastern sea coast of the US is called the:

Answer: Gulf Stream

Q9. How does human activity impact infiltration?

Answer: It creates impermeable surfaces and more runoff

Q8. What does the atmosphere do?

Answer: Keeps us warm, protects us from the sun, gives us gases we need to live, Keeps water in liquid form

Q9. Which of the resource can NOT be found in the desert?

Answer: Logging

Q5. How does the packing of a material impact porosity?

Answer: Loosely packed soils have a higher porosity.

Q4. Which is NOT a greenhouse gas in Earth's atmosphere?

Answer: Oxygen, O2

Q4. How does particle shape affect porosity?

Answer: Rounder particles have a higher porosity.

Q7. What is the largest desert on Earth?

Answer: Sahara

Q6. How does the amount of sorting impact porosity?

Answer: Sorted materials have a higher porosity

Q3. Which layer of the atmosphere contains the ozone layer?

Answer: Stratosphere

Q5. How is the troposphere warmed?

Answer: The Sun warms Earth's surface, which warms the air above it.

Q7. What is permeability?

Answer: The ability of water to pass through a material.

Q3. What is the definition of porosity?

Answer: The amount of pore space in a material.

Q4. Which layer of the atmosphere is named after its high temperature?

Answer: Thermosphere

Q3. Why are certain compounds considered to be greenhouse gases?

Answer: They reflect infrared radiation back to the Earth's surface

Q8. Which human impact on the desert can be seen in the image?

Answer: Tourism

Q2. Within which layer of the atmosphere do you find rain, snow, and clouds?

Answer: Troposphere

Q4. Deeper, colder, nutrient-rich water that comes to the surface near coastlines is called a(n):

Answer: Upwelling

Q8. Which is true of vegetation?

Answer: Vegetation slows water down and increases infiltration

Q10. When is flooding likely to occur?

Answer: When soil is impermeable

Q7. A stream carries rocks and pebbles as

Answer: bedload

Q2. Older rivers often have large areas of flat land next to the river. This is called the

Answer: flood plain

Q6. CO2 concentrations have increased greatly in the last 100 years due to _________.

Answer: fossil fuel combustion

Q2. This process keeps Earth from being a frozen planet without life.

Answer: greenhouse effect

Q6. All water stored underground

Answer: groundwater

Q7. Your ears may pop on an airplane because pressure is moving from

Answer: high to low (gaining altitude)....

Q2. What do scientists believe is causing coral bleaching?

Answer: increased temperature

Q1. The seeping of water into the ground is known as

Answer: infiltration

Q7. Compared to historical trends, what is different about recent climate change?

Answer: it is warming at an accelerating rate

Q9. A curve in a river is a

Answer: meander

Q1. Ocean debris of trash, plastic, glass, and foam often collects where?

Answer: middle of Gyres

Q3. A river can build up thick deposits along its sides. This is called

Answer: natural levee

Q1. What is the most abundant gas in Earth's atmosphere?

Answer: nitrogen

Q5. A meander in a river cut off from the main stream is called

Answer: oxbow lake

Q7. What causes surface currents in the oceans?

Answer: prevailing winds

Q8. Which of the following is a possible affect from global climate change?

Answer: rising sea levels, species extinctions, increased drought and food shortages, stronger, more frequent storms

Q2. Precipitation that flows over Earth's surface is called

Answer: runoff

Q5. Most ocean pollution caused by humans comes from:

Answer: runoff from land

Q10. A deposit of sand near shore

Answer: sandbar

Q4. When the ground is holding all the water it can possibly hold it is

Answer: saturated

Q5. What is responsible for the increase in greenhouse gas concentrations starting around 1800?

Answer: the industrial revolution and fossil fuel emissions

Q9. Which layer of the atmosphere contains auroras (northern lights)?

Answer: thermosphere

Q8. The top or upper surface of the zone of saturation (for groundwater) is

Answer: water table

Q1. The land that drains into a single river

Answer: watershed or drainage basin

Q1. Climate is the pattern of __________ in an area over many years.

Answer: weather

Talus

Apron of debris sloping outward from cliffs

confined aquifer

Aquifers covered by an impermeable and confining layer impeding water flow in or out.

floods

Artificial levees can be counter-productive. They keep the water in the channel and as it goes downstream, the flood level rises higher than it normally would.

Deere & Miller

As elasticity increases, strength increases. Modulus ratio

toxic dissolved materials

As, Hg, Pb

Rock Quality Designation

Assessment of quality of rock mass

What was the cause of the ozone hole over Antarctica?

Atmospheric release of cholera-fluorocarbons

flood recurrence interval

Average time hiatus between floods of a given size

What does the Milankovitch Theory postulate?

B. Changes in Earth's eccentricity, tilt, and precession produce climate change

base of glacier

Basal sliding causes scouring, grinding, crushing, etc. Erosion is proportional to thickness.

Basins

Beds dip into center

Dome

Beds dip out from center

Hanging wall

Block above the fault

Footwall

Block below the fault

Recumbent

Both limbs approach horizontal

Continental Shelf

Buildup of biogenic material

which is the most efficient greenhouse gas?

C. CH4

travertine deposits

CaCO3 deposits around geyser at surface

what do coral polyps secrete?

CaCO3 shells

Joints/fractures/faults

Can cause mass movements. Jointing occurs during rock formation and faulting occurs in tectonically active regions, which also develop relief

Friction

Can hold dry regolith together.

Coriolis effect

Causes moving air and water to turn left in the southern hemisphere and turn right in the northern hemisphere due to Earth's hemisphere.

Longitudinal profile

Change in height

What does the Milankovitch Theory postulate?

Changes in the Earth's eccentricity, tilt, and precession produce climate change

Dip-slip faults

Characterized by blocks that move parallel to the dip of the fault. Subdivided into normal (extensional) and reverse (compressional)

Gyres

Circular flow patterns

seawater composition

Cl- 19.35%, Na+ 10.76%, (So4)2- 2.71%, Mg2+ 1.29%, Ca2+ 0.41%, K+ 0.39%, HCO2- 0.14%, Br- 0.067%

Rockslide

Coherent mass moves. Movement along a plane parallel to the surface.

Unconfined pressure test

Common method of testing rock behavior. Press really hard until failure

Triaxial test

Confining pressure can be applied to better mimic depth condition.

A craton consists of

Crust that has not been affected by orogeny for over 1 billion years.

Milankovitch Theory

Cycles recorded in tills and from oceanic cores suggest wobbles every 21,000, 41,000, and 100,000 years.

Drainage

Decreasing water content of the mass. Subsurface drainage wherever the substrate is permeable.

Thalweg

Deepest part of channel

Submarine fans

Deposits form submarine fans on the abyssal plains.

rain shadow deserts

Desert formed on the leeward side of a mountain range because the height of the mountain prevents most moisture from crossing over it

How could global climate change trigger an ice age in the Northern Hemisphere?

Dilution of seas water shuts down ocean currents

Dry wash (wadi)

Dry stream bed (courtesy of an ephemeral stream)

How could global climate change trigger an ice age in the Northern Hemisphere?

E. Dilution of seawater shuts down ocean currents

axis tilt

Earth's rotational axis is inclined to its orbit around the sun, but this varies between 22.5-24.5 degrees over ~41,000 years

Open folds

Either form from bending or buckling.

____ form where river valleys have been flooded, whereas ____ forms where glaciated valleys have been flooded.

Estuaries, fjords

mountain glaciers (alpine glaciers)

Exist in or adjacent to mountain ranges. Include valley glaciers, mountain ice caps (cover the mountains), piedmont glaciers.

Accretionary orogens

Exotic terrains are accreted to the edges of shields

Flow

Fast, downhill

Blind faults

Faults that do not reach the surface until revealed by erosion

Abyssal plain

Flat, extends into ocean basin

Tidal bore

Flood tides can produce a wall of water

Mudflow (lahar)

Flowing mixture of debris and water, usually moving down a channel. Can occur after heavy rainfall or due to volcanic activity. Typically occurs in areas where vegetation is sparse...lahar is when volcanic ash mixes with rain or glacial ice.

Stress

Force per unit area. Types include hydrostatic, tensional, compressive, shear

What is the Matric potential of unsaturated zone material?

Forces that act against gravity

Point bars

Form in corners of meanders, accentuate curvature

alluvial fans

Form when a constrained channel becomes unconstrained - velocity decreases and coarser grains get deposited. Typically form when rivers emerge from a mountain range.

Alluvial fans

Form when a constrained channel becomes unconstrained. Typically form where a stream emerges from a mountain range

deltas

Form when river enters a body of water and velocity decreases

Slot canyon

Formed by downcutting which leads to wall slumping

V-shaped canyon

Formed by downcutting which leads to wall slumping

Fall

Free-falling motion

Tidal friction

Friction between ocean and basin cause the tidal bulge to lag slightly behind the movement of the Moon.

Stream velocity

Function of stream gradient and frictional resistance

What is Glacial Advance?

Glacial accumulation exceeds wastage

transport of sediment by ice

Glaciers act as large-scale sediment conveyor belts. Sediment falls onto a glacier and gets plucked up from below. This material is transported to the toe where it piles up as an end moraine (if toe is stagnant)

when global temperatures fall

Global warming

example of loess

Gobi Desert

Mohr's circle

Graphical representation of shear and normal stresses on inclined planes.

What causes tides?

Gravity

Due to latitudinal variations in insolation, the ____, ____, and ____ circulation cells develop in each ____.

Hadley, Ferrel, Polar, hemisphere

Isoclinal folds

Hairpin. Parallel limbs

Oblique-slip faults

Have components of both dip-slip and strike-slip faults

Stream capture

Headward erosion allows one stream to capture another

Nonplunging folds

Hinge is horizontal. Dips switch as you go from limb to limb.

Plunging folds

Hinge is inclined. Anticlines point in the direction of plunge, synclines point the other way.

What describes a Barchan sand dune?

Horns point downward, bows into the wind, limited sand

glacial lakes

Ice-margin lakes due to melting, deltas, beaches, lake clays remain = Proglacial lakes (ice dammed).

Stream terraces

If base level drops and/or uplift occurs, streams cuts alluvium and forms stream terraces.

Shear strength

If shear stress exceeds shear strength, failure occurs.

Seismic reflection

Imaging technique for sea floor

Creep

Imperceptibly slow down-slope movement. Affects the upper few meters only. Enhanced by frost heaving, wetting and drying cycles, washing away of fine particles

Slip

In contact with surface beneath

Joints

In sedimentary rocks, joints are typically vertical. Joints allow water to flow and decrease rock strength.

ultimate fate of the earth

In some 5 billion years, the Sun will run out of hydrogen and collapse inward. This will generate enough heat for the outer layer of gases to expand and form a red giant. The red giant phase will expand the remnant Sun past the orbit of Earth. Earth will vaporize, another in a long series of cycles.

Urbanization

Increases run-off and peak discharge amounts due to concrete/tarmac (prevents infiltration).

urbanization

Increases run-off and peak discharge amounts due to concrete/tarmac (prevents infiltration).

plastic deformation

Internal plastic deformation involves recrystallization, stretching, and rotating of grains. It occurs in both wet- and dry-based glaciers

what happens when a storm reaches tropical depression status?

It is given a name; names of particularly notorious storms are never used again

Vein

Joint filled with minerals precipitated from groundwater.

largest glacial lake

Lake Bonneville. 50,000 km2, 335 m deep. Salt deposits of Salt Lake City formed as part of it dried up.

Ox-bow lakes

Lakes formed by meanders that eventually cut themselves off

cravasses

Large cracks in the ice sheet- they can be more than 100 feet deep.

submarine fans

Large fan-shaped deposits of fine-grained sediments that accumulate on the abyssal plains

pluvial lakes

Large lakes formed as a result of greater precipitation and overall cooler temperatures - far away from glaciers

varves

Light and dark layers of sediments deposited in a yearly cycle

Hinge line

Line defining the fold axis (in one dimension)

Fold axis

Line made by the intersection of the axial surface with the beds. If axis is not horizontal, it is plunging

Thrust faults

Low angle reverse faults. Can juxtapose old rock on top of young rock. Can transport sheets 100s of Kms and are common features at the leading edge of orogenic formation

local and ultimate base level

Lowest point overall and in a specific region

Changing slope angle

Major cause of instability

Artificial levees

Man-made structures that slow flow and prevent tributaries from joining, prevent floods

Slumping

Mass of regolith detaches from its substrate along a spoon-shaped, sliding/failure surface; slips coherently downhill., Failure: surface along which the slump occurred. Toe may end up at higher elevation and break into smaller slices.

Brittle

Material breaks

outwash

Material deposited by glacier as it melts, similar to deposits. Sorted and separated by the size of its particles.

Ductile

Material flows

stream capacity

Maximum load stream can carry. Streams are rarely loaded to capacity because weathering & erosion are slow processes.

Stream competence

Maximum particle size a stream can carry

Angle of repose

Maximum stable slope, which is a function of rock type and climate. (Dry = steep, wet = shallow). And size and shape of grains (determine amount of friction)

future climate change

Model calculations of extent of global warming with variation in CO2 input; even low emissions model shows substantial warming.

Orogeny

Mountain building, plate convergence. Mountains occur in curvilinear belts unless a volcano hotspot is involved. Involves geologic processes including deformation, jointing, faulting, folding, partial melting, etc.

dry-bottom glaciers

Movement occurs through plastic ice crystal deformation and pressure solution. Typifies polar glacier movement. Slower than above.

Generalized Stress-strain curve for rock

Not linear. Region 1: closing of void spaces. Region 2: Approximately elastic behavior. Region 3: Approximately plastic behavior. Failure: rock breaks and loses all shear strength

Bars

Obstruction/formed by alluvium

Bathymetry

Ocean depth, measured using SONAR

parallel

On a uniform, fairly steep slope, several streams with parallel courses develop simultaneously. Typically form on on the sides of steep escarpments of weak substrate. If the weak substrate has no sediment on top of it, it is called badlands topography

Overturned

One limb is now the wrong way.

Folds

Open, isoclinal (tight, hairpin), Chevron, tight overturned folds (one limb upside down), recumbent fold (both limbs flat, one limb upside down)

Weakest Link Principle

Overall strength of a rock not determined by bulk properties, but by strength of weakest link. When rock mass undergoes stress, it will preferentially fail along existing planes of weakness

What did life need to develop beyond single-celled organisms?

Oxygen and Ozone

Intrinsic permeability

Permeability defined by the property of the material., size, shape, packing of grains; degree of cementation; degree of fracturing

Normal stress

Perpendicular to the plane

ice bergs

Pieces of ice sheet/glacier calve off the main mass and float in the sea. 4/5ths below sea level

Elastic Limit

Point at which ductile material begins to act in plastic fashion

Septics systems and leaky petroleum tanks are examples of ____ sources of contamination, whereas fertilizers and pesticides are examples of ____ sources.

Point, nonpoint

unsaturated zone (zone of aeration or Vadose zone)

Pore spaces only partially full of water, lies between the water table and the surface, only partially full of water

secondary porosity

Porosity produces after the rock formed. Dissolution, faulting, jointing, etc.

how do geysers erupt?

Pressure eventually pushes water passed the constriction - pressure drop and flash boiling +eruption

Landslide potential maps

Rank regions according to likelihood a mass movement will occur.

Slope reduction

Reduce slope angle, place additional supporting material at foot of slope to prevent a slide or flow, reduce the load by removing rock high on slope

Ductile

Respond elastically until the Elastic Limit, then in plastic fashion until failure

Brittle

Respond in a mostly elastic fashion until failure

Rockfall

Rock free falls due to undercutting

pollutants

SO4^2-,NO3^- : react with water to form acid rain., CO2 from fossil fuel burning - greenhouse gas., Chlorofluorocarbons (CFCs) - destroy ozone. Accumulates over the poles to form "ozone holes"

how are hurricanes classified?

Saffir-Simpson Scale

glacial striations

Scratches and grooves on bedrock caused by glacial abrasion

Avulsion

Sediment deposition builds out the toe of the delta and reduces the gradient. Eventually, the river cannot flow in this channel - the natural levee is topped upstream and the river makes a new path to the sea.

avulsion

Sediment deposition builds out the toe of the delta and reduces the gradient. Eventually, the river cannot flow in this channel - the natural levee is topped upstream and the river makes a new path to the sea.

Cohesion

Slightly wet regolith can be held together by surface tension

Cause of instability

Slope undercutting, Overloading slopes, Adding water

primary porosity

Space that remains between solid grains/crystals after sediment accumulates or rocks form.

Air pressure

Storm surge can push high tides higher

Elastic

Strain is recoverable, slope of regression line is modulus of elasticity, i.e. spring

Downcutting

Stream erodes and makes channel deeper

Headward erosion

Stream migrates upward, flow is more intense at entry to channel

Avalanche bridges

Strong bridge over a road when avalanche is channeled so as not to take out cars

Retaining structures

Sturdy walls that help keep regolith upright, prevent collapse, fall, slide

Drilling

Sub-seafloor sampling

Olistostromes

Submarine slumping. Semi-coherent blocks slip downslope on weak mud detachments. Occasionally, the layers constituting the blocks become contorted as they move

Axial surface

Surface that divides the fold as symmetrically as possible (aka Axial Plane)

Water table

Surface that is the contact between saturated and unsaturated zones.

Flood hazard maps

Takes data of flood recurrence intervals and maps out most dangerous areas

Layering developed by the alignment of grains in response to deformation is called

Tectonic foliation

Solifluction

Thawing away permafrost on slopes promotes slow downhill movement.

air flowing from high to low pressure is affected by?

The Coriolis Effect

polar front

The convergence zone in the atmosphere at latitude 60 degrees

hydrologic cycle

The cycle through which water in the hydrosphere moves; includes such processes as evaporation, precipitation, and surface and groundwater runoff

Plunge pool

The deep part at the very base of waterfall

coriolis effect

The effect of Earth's rotation on the direction of winds and currents.

What is the property hydraulic head?

The elevation to which groundwater would rise in a pipe penetrating the aquifer.

Dip

The maximum angle by which a planar feature deviates from the horizontal, always measure in the plane perpendicular to the strike (orientation where dip is zero)

zone of accumulation

The part of a glacial system where snow and ice are accumulating faster than they are melting away.

What is the Ghyben-Herzberg relationship?

The saltwater-freshwater interface is 40 x the height of the water table above seas-level

Hydraulic gradient is roughly equal to

The slope of the water table

dewpoint temperature

The temperature at which air becomes saturated with water so it precipitates.

Horst

Uplifted block due to fault

Debris slide

Upper part of earth flow where rotational sliding typically occurs. Regolith slides

downcutting < wall slumping forms a ______

V-shaped valley

Chevron folds

V-shaped, tight. Axial plane is not vertical

Graben

Valley due to fault

Failure envelope

Varying principle stresses (both axial and confining) allows for creation for multiple Mohr's circles and definition of failure envelope

continental glaciers

Vast ice sheets covering continents - Greenland, Antarctica. Flow out from the thickest point. Front edge may form several tongue-shaped lobes due to differential speed.

Incised meanders

Very deep, curvy meanders

Fluid

Viscous and plastic. Plastic = No strain until some critical stress value has been reached; then continuous deformation

carbon cycle

Volcanic CO2 is added to the atmosphere, where it can be removed by:

what are dry washes/arroyos called in the middle east

Wadis

Productive wells

Water table reaches entrance to well

Nor'easters

Wave cyclones affect Atlantic coast - winds out of the Northeast, huge storms ("perfect storm") can build seas to 11 m

Direct shear test

Way to test shear strength. Variable shear and normal stresses can be applied.

Bedding

Weak horizontal surface

Foliation

Weak layered surface

Exfoliation

Weak tilted surface

isostatic readjustment

Weight of ice causes uppermost mantle to move aside, crust sinks. When ice melts it takes a while for the mantle to flow back. Rebound occurs over thousands of years

Orogenic Collapse

Weight of mountain causes warm crust at depth to flow laterally.

Confining pressure

Weight of overlying rock applies pressure in all directions to given body of rock. Not always equal in all directions.

Dry wells

Well not deep enough to reach water tables

beveling topography

When base level drops, a new

How is the matrix potential measured?

With a tensiometer

Ungraded and graded streams

Young stream becomes graded as it ages, gets deeper

Normal fault

Younger strata over older. Hanging wall moves dow relative to footwall

Syncline

Youngest rocks at center, beds dip into youngest rocks. If age of rocks is unknown, it is called a synform.

Greenland ice

_____ of plankton shells in marine sediments gives a record of millions of years

ratio of 18-O to 16-O is large in snow that forms in warmer air and smaller in snow that forms in colder air

______ _____ gives a record back > 120,000 years

a rise in the average surface temperature of just a few degrees is enough to melt the polar ice caps and cause a dramatic sea-level rise

________ % of world population lives at/near coasts

air mass

a body of air (at least 1,500 km across) that has recognizable physical characteristics.

the atmosphere is separated into layers depending on:

a change of temperature decrease to increase and vice versa

what does each continental margin have?

a continental shelf/continental slope

plunge pool

a deep basin excavated at the foot of a waterfall by the action of the falling water.

what is estuary?

a drowned river valley

pollution

a material that contaminates air, water, soil. Modern society generates a vast array of solid, liquid, and gaseous contaminants that overwhelm natural attenuation mechanisms. Contaminating materials may be natural or synthetic

conduit

a pipe or channel through which something passes

oases

a place, usually in a desert, where water can be found - formed by the surface water fed aquifers

what forms if there is sufficient water flowing into a desert basin?

a salt lake due to great evaporation concentrating the dissolved ions

horn

a sharp peak formed where several cirques meet at the same point

tarn

a small mountain lake

weather system

a specific set of weather conditions that affects a region for a period of time

bioremediation

a technique that utilizes bacteria to clean groundwater

what feature is between two glacial valleys?

a. an arete

what was the cause of the ozone hole over Antarctica?

a. atmospheric release of chloro-fluorocarbons

Generalized rock deformation curves show 3 segments, which are (starting at low deformation):

a. closing of void spaces, elastic behavior, plastic behavior

What are chevron folds?

a. folds with angular apexes

what causes tides?

a. gravitational forces

what describes a barchan sand dune?

a. horns point downwind, bows into the wind, limited sand

Slow movement of material downslope in a cold climate is called

a. solifluction

Streams that cut through unconformities are called

a. superposed streams

what is the property hydraulic head?

a. the elevation to which groundwater would rise in a pipe penetrating the aquifer

exosphere

above the heterosphere

how are pot holes formed?

abrasion

volcanic features (Ocean basin floor)

abyssal hills, seamounts, aseismic ridges, guyot

terminus advances

accumulation < ablation

the balance between addition by accumulation and loss by ablation

accumulation > ablation

acidification

acid rain and acid runoff

continental margins divide into ?

active and passive

Swelling clays

addition of water promotes swelling of clays as water is absorbed between clay sheets. Dehydration causes shrinkage.

other sources of pollutants

agriculture, destruction of permafrost, methane deposits, etc.

human-caused contamination

agriculture, industry, effluent from "sanitary" landfills and septic tanks, petroleum products, radioactive wastes, acid mine drainage

loess

air above ice-free land is warmer and rises. cold air off the glacier rushes in - katabatic wind. Picks up fine material from the glacier's toe and deposits it

convergence lifting

air converges, spirals up in a low pressure zone or where 2 winds that have been deflected around an obstacle meet and have nowhere to go but up

deserts of the polar regions

air has moved north and cooled by cold oceans (reduced moisture). Now it rises, expands and rises further. Above 66º N and S latitude there is very little moisture in the air due to cold temperatures. Air circulation carries air to the polar regions, but it is so cold, the air can't hold any moisture.

jet streams

air is thicker and warmer at the top of the troposphere over the equator compared to the poles. This causes the higher altitude air to flow north (or south). The Coriolis Effect makes these "high-altitude westerlies" that move at 200-400 km/hr

Coriolis Effect in the Northern Hemisphere

air moves counterclockwise (creating a cyclone) around a low-pressure mass, and clockwise (creating an anticyclone) around a high-pressure mass

adiabatic cooling

air moves from high to low pressure, without adding or subtracting heat, it expands and cools

adiabatic heating

air moves from low to high pressure, without adding or subtracting heat, it is compressed and heats up.

orographic lifting

air rises over landmass/ mountain range

saturated zone (phreatic zone)

all of the pores in the rock or sediment are filled with water

a graded stream can carry

all the sediment that has been supplied to it

where do coral reefs develop

along coasts, 0-30 degrees latitude

dam construction

alters river ecosystems by decreasing water and

Dam construction

alters river ecosystems by decreasing water and sediment/ nutrient flow downstream. Positive side - irrigation for agriculture, hydroelectric (clean) power.

unconfined aquifer

an aquifer made of porous rock covered by soil out of which water can easily flow

drainage basin

an area in which all runoff flows into a single stream (e.g. Mississippi River and on more local scale)

Drainage Basin

an area in which all runoff flows into a single stream.

Reach

any segment along the length of the stream

reach

any segment along the length of the stream

An aquifer not overlain by an ____ is called ____ whereas if it is it is called ____

aquitard, unconfined, confined

intertidal zone

area covered at high tide and exposed at low tide

discharge

area where water leaves an aquifer system

desert

area with less than 25 cm of precipitation annually

desert

area with less than 35 cm of precipitation annually, defined by aridity not temperature

deserts are defined by ____ not by ______

aridity, temperature

saline intrusion

around the coast, salt water will replace freshwater in an aquifer. This replacement is permanent

graded

as a stream smooths its longitudinal profile to concave-up shape, it becomes this

interrupting the global heat conveyor

as climate cools, evaporation from the sea decreases so the sea is less salty. This can alter ocean currents and may cut off warm ocean currents to high latitudes. This may also occur with global warming as more freshwater may enter the system due to higher rainfall, also reducing salinity in some parts of the oceans.

granular snow

as ice compacts, flakes undergo pressure solution

u-shaped valley

as opposed to "v-shaped" valleys caused by rivers or water flow. these can be recognized on topographic maps

lowering the water table

as the cone of depression expands, the regional water table is lowered, destroying wetlands and rivers

Cuesta

asymmetric ridge developed due to gently dipping strata

how is discharge measured?

at a Stream-gauging station

where is the flow more intense?

at the entry to the channel

nonliving reservoirs

atmosphere, crust, oceans

Flood recurrence intervals

average time hiatus between floods of a given size

climate

average weather conditions during the year or longer

what does the Milankovich Theory postulate?

b. Changes in Earth's eccentricity, tilt, and precession produce climate change

what is an estuary?

b. a drowned river valley

streams that maintain their flow patterns as the ground rises in a tectonically active area are called

b. antecedent streams

what is the definition of wave length?

b. distance between two adjacent wave crests

what is glacial advantage?

b. glacial accumulation exceeds wastage

how is the modulus ratio of rocks defined?

b. ratio of the modulus of elasticity to the unconfined compressive strength

hydraulic gradient is roughly equal to

b. the slope of the water table

where is the jet stream located?

b. tropopause

crescentic dunes

barchan dunes, parabolic dunes

breakwaters

barriers built offshore and parallel to the coast to protect boats from breaking waves

ordinary well

base penetrates the aquifer below the water table. Water seeps in and fills it to the level of the water table. Some may be dry part of the time. Either drop a bucket down or pump water out.

what do longshore currents produce?

beach drift - beaches are "moved", spits and baymouth bars

irregular sand dunes

beach dunes, star dunes

patterns produced depend strongly on the nature of the _____

bedrock

pediment

bedrock surfaces that extend out from the mountain front to the alluvium-filled valleys

pediment

bedrock surfaces that extend out from the mountain front to the alluvium-fitted valleys. Formed by sheetwash

Headwater

beginning of the streams, high elevation in the drainage basin

headwater

beginning of the streams, high elevations in the drainage basins

River

big stream

river

big stream

size of the conduits

bigger is better

ground moraine

blanket of till

Strike-slip faults

blocks move parallel to fault plane strike. Divided into right lateral and left lateral. Named by standing on one side and seeing which way (right or left) the other side has moved relative to the side you are standing on.

stream

body of running water that flows in a channel

erratic

boulder transported from a distant area and deposited (usually) in a geologically different region

front

boundary between air masses

Rocks exhibit two general responses to deformation: ___ and ___ behavior.

brittle, ductile

plateaus

broad, flat-topped areas elevated above the surrounding land and bounded, at least in part, by cliffs

mesa

broad, flat-topped hill bounded by cliffs and capped with a resistant rock layer - wider than it is high

mesa

broad, flat-topped hill bounded by cliffs, wider than high

trees, corals, stalagtites/stalagmites. Bristelcone pines extend the record back 4,000 years. Go back further by logs dated by radiocarbon that overlap with live trees

bubbles in ice

recessional

built up during the retreat (defines periods of no retreat or small advances)

which is the most efficient greenhouse gas?

c. CH4

what is a bajada?

c. Sediment deposits of coalesced alluvial fans

which of the following terms is NOT associated with the process of mountain building?

c. cratonic platform

An array of interconnecting streams together constitute a

c. drainage network

Streams that do not flow year round are called

c. ephemeral streams

a defense used to slow the undercutting of cliffs by wave action is called

c. riprap

what is the amount of deformation a rock experiences called?

c. strain

what is the boundary between the stratosphere and the mesosphere?

c. stratopause

identify the FALSE statement. Mountains don't get infinitely high or exist forever because:

c. they are eventually subducted in the plate tectonic cycle

dune migration

can be >15 miles/year, but this depends upon wind velocity, persistence, obstacles.

Abyssal hills

can be up to 1,000 meters high. (volcanic)

wind erosion

can carry sediments long distances, including uphill

Just above the water table the ____ ____ is subdivided into the ____ ____ just above the water table, and the ____ ____ just above that.

capillary fringe, funicular zone, pendular zone

-dissolving in oceans (eventually) as HCO3^- ions, Absorption by organisms for food, dissolving in rain and being used in chemical weathering reactions, precipitation as CaCO3, burial and removal as fossil fuels

carbon is put back into the atmosphere by:

changing climates

cause desert encroachment on cities = desertification; caused by overuse of land. Violent storms especially in tropics. Wind power.

stream rejuvenation

caused by uplift and/or base level drop. can also cause incised meanders

eolian landscapes

caused by wind

expansion of deserts

caused by: overgrazing, overpopulation, water diversions., Too many people = over farming and increased water use., Diversion of water for agriculture upstream, climate change - drought

where is flow velocity the greatest in a glacier?

center

hydraulic gradient

change in hydraulic head between 2 locations as measured along the flow path

Strain

change in shape due to deformation

global change

change in the steady state situation (i.e. relative proportions of a chemical held in a reservoir at a given time)

how does a dam interrupt a graded stream

changes base level, changes stream grade, modifies sediment movement. sediment builds up behind the dam - downstream is then sediment-starved

eustatic sea-level changes caused by:

changes in volume of mid-ocean ridge, glaciation/deglaciation

biogeochemical cycles

chemical fluxes between living and nonliving reservoirs

Atolls

circular reefs that rim lagoons and are surrounded by deep water; small wave-built islands

thermohaline circulation

circulation due to density contrasts. Water in polar regions sinks (cold/more salty); water that is warmer/less salty rises

features found at the head of a glacial valley include ____, ______, and _______, and the overall profile of the valley is ____-______

cirques, horns, tarns, U-shaped

Clastic load

clasts of sediment being moved by the river (made up os suspended and bed loads)

what do coral reefs need?

clear, well lit, warm (18-30 degrees) water with normal salinity

what do oceans regulate?

climate, cycle mass, energy

depth to water table depends on ___ and _____

climate, season

CO2 in the atmosphere has steadily _____ since the first direct measurements in 1958

climbed

surface currents: _____ in the N. Hemisphere, ____ in the S. Hemisphere

clockwise, counterclockwise

generalized rock deformation curves show 3 segments, which are (starting at low deformation)...

closing of void spaces, elastic behavior, plastic behavior

what does adiabatic cooling form?

clouds

fog

clouds at the surface

humid regions

cm to m below surface

lag deposit

coarse material left behind by wind

older ice is _____ grained

coarser

what happens when a cold front moves in?

cold air mass pushes below a hot air mass, the hot air rises, cools adiabatically, and water condenses and heavy rains ensue

katabatic wind

cold air off the glacier

Bergeron Process

cold air, tiny ice crystals form and lead to growth of snow flakes. If the air below is very cold, it falls as powder snow; if the air is close to 0˚C, it falls as "wet snow"; if the air is >0˚C, it falls as rain.

Compression, due to plate ____ and ____ shortens the crust ____ and thickens it ____.

collision, convergence, horizontally, vertically

flash floods

common in deserts

active margins are ___ relative to passive margins

compressed

hydraulic action

compression of air in joints/cracks/planes of weakness

Rocks can undergo three types of stress:

compression, extension, shear

homosphere

comprises Mesosphere, Stratosphere, Tropopause and each layer has the same composition

ice crystals move in a _______ ______ profile which is important for meteorite collections

concave upward

groundwater flows along _____ paths, indicating that some groundwater can flow down deep into the crust

concave-upward

pumping may produce a ______ which may lower the water table if pumping exceeds replenishment, and may also cause shallow wells to dry up

cone of depression

reversing groundwater flow

cone of depression creates a local slope that induces pollutants to flow into the well

types of aquifers

confined and unconfined

The strength of a rock increases with increasing ___ ___ and decreases with increasing ___.

confining pressure, temperature

why aren't barrier islands good to live on?

constantly

if human-caused contaminants get into groundwater, they produce a ______ _____ as they flow away

contaminant plume

The two glacier types are ____ and ____, and these can be further subdivided into ____ and ____.

continental, mountain, temperate, polar

Principle of Isostasy

continents float by displacing the asthenosphere

air rises through several mechanisms:

convective lifting, frontal lifting, convergence, orographic lifting

compression stress at convergent plate margins is due to plate ______ and ________

convergence, collision

compression stress at convergent plate margins is due to plate ____ and ____, which shortens the crust ____ and thickens it ____.

convergence, collision, horizontally, vertical

combination of surface and deep water circulation produces a ______

conveyor belt of ocean circulation

any process that decreases the amount of greenhouse gases:

cools the atmosphere

the ____ ______ is a phenomenon created by Earth's rotation and causes a deflection of _____ or ____ flowing over Earth's surface

coriolis effect, wind, water

which of the following terms is not associated with the process of mountain building?

cratonic platform

why does groundwater flow much slower than surface water?

crooked pathways and friction (including electrostatic attraction between water and the conduit walls)

what does dune migration produce?

cross bedding

cloud types

cumulus, stratus, cirrus

Meander

curving reach

meander

curving reach

what are hurricanes called in the indian ocean?

cyclones

What is the Bergeron Process?

d. formation of ice crystals at the expense of rain drops

what causes waves to break?

d. friction

turbidity currents produce what kind of sedimentary structure

d. graded bedding

which of the following cloud types forms lowest in the atmosphere?

d. stratus

Quick Clay

damp clay flakes behave as a solid when still--water-coated flakes held together by surface tension

industry contamination

dangerous organic and inorganic compounds

without greenhouse gases, earth would be a:

dead, frozen world

Earthflow

debris moves downslope as a viscous fluid, slow or rapid movement, typically after heavy rains. Produces a scarp at the top and hummocky toe or lobe at the end.

As river flows towards the mouth, gradient _________, discharge _______, channel ______ in size and is ____ constrained (i.e., floodplain increases)

decreases, increases, increases, less

Dry Washes/Arroyos

deep channels with steep sides

thalweg

deepest part of the channel

initial movement of wind erosion =

deflation - requires dry grains that are not restricted by vegetation (or water)

what is human-induced ecosystem a consequence of?

deforestation, overgrazing, agriculture, urbanization

alluvial fan

deposit of sediment at the mouth of a valley

talus slope

deposit of weathered material along a steep slope

kettle

depression in glacial outwash formed by the melting of a detached block of ice

blowout

depression scooped out by deflation, erosion stops when the water table is reached

blowout

depression scooped out by deflation, erosion stops when water table is reached

Thermocline

depth below which water temperature decreases abruptly.

velocity changes with

depth of channel, river bendiness

the transformation of non-desert areas to desert is called _____

desertification

land overuse, wind, climate change, diversion of water, unprotected fields

desertification caused by:

water erosion

deserts get most of their rain all at once. Lack of vegetation means loose material is easily moved. streams are ephemeral.

Individual faults in a system may merge at depth with a near horizontal

detachment fault

latitude

determines the amount of solar radiation that reaches a given region (along with the season)

darcy's law

determines the volume of water that flows through an area of aquifer in a given time (discharge, Q)

meanders

develop on the floodplain as river changes from vertical to lateral erosion - it "wanders" over the floodplain

tidal reach

difference between high and low tides

what causes groundwater to flow uphill?

differences in pressure

rock steps & rock basins

differential erosion down a valley

main control on the development of southwest features?

differential erosion rates - differential hardnesses

trellis

dipping beds of sedimentary rocks of alternating resistance to erosion (e.g. alternating limestone and sandstone)

groundwater usage problem "fixes"

direct surface run-off to recharge areas or pumping surface water back into the aquifer

Darcy's Law states that ____ depends on the hydraulic ____ and the ____.

discharge, gradient, permeability

shape of delta controlled by interplay of river ____ and _____ currents

discharge, offshore

perched water tables

discontinuous aquitards

4 ways stream erosion occurs:

dissolution, scouring, breaking & lifting, abrasion

why is seawater more dense than freshwater

dissolved ions, -products of chemical weathering of rocks and transported to the sea via rivers

streams pick up sediment, which is carried as the ___ load, the ___ load, and the ____ load.

dissolved, suspended, bed

how does groundwater produce sinkholes?

dissolves rock, especially limestone

chemical weathering in deserts

does occur, but slowly. Dew and some rain percolates in cracks and fractures and leaches material out of the rock, reducing its integrity. Amount of water is not enough to flush it out of the system. Deposits material lower down - if calcite has been dissolve "calcrete" is deposited because it cements loose grains together

winds in the divergence and convergence zones

doldrums - weak, erratic

what do heterogeneities in the surface promote channel formation through?

downcutting

The stability of a slope reflects the relative sizes of ____ force and ____ force.

downslope, resistance

glacial marine

drop stones; sediment carried into the sea by a glacier

fjord

drowned U-shaped (glaciated) valley

estuary

drowned river valley. protected from wave action - water becomes stratified. Denser salt water beneath freshwater

fjord

drowned u-shaped valley

what do desert landscapes reveal

dry drainages

What do flash floods quickly infiltrate?

dry stream beds

Rocks exhibit two general responses to deformation: ____ and ____ behavior.

ductile, brittle

cliff retreat

due to joints being weakened through weathering and lack of vegetation to smooth out the slope

cliff retreat

due to joints being weakened through weathering and lack of vegetation to smooth out the slope.

hanging valley

due to tributary glaciers joining the main glacier. greater erosion in the main valley

colored bedrock

due to variations in amount of Fe and oxidation

velocity, abundance of sand, vegetation

dune shape is based on:

Void ratio

e =Vv/Vs = Void volume/Volume of solids

what is an esker?

e. a long sinuous ridge of water-deposited sediment

Individual faults in a system may merge at depth with a near horizontal

e. detachment fault

How could global climate change trigger an ice age in the Northern Hemisphere?

e. dilution of seawater shuts down ocean currents

what is the problem that overpumping of an aquifer does NOT cause?

e. hard water

glaciers entering the sea from continents form broad, flat sheets called:

e. ice shelves

on a plane within a rock body...

e. normal stresses tend to resist failure

Blocks formed through mass wasting and collect at the bottom of slopes are called

e. talus

what is the phreatic zone?

e. the saturated area below the water table

Rocks whose surface has been faceted by wind are called:

e. ventifacts

the moons orbit

earth rotates every 24 hours on its axis. Moon orbits the earth every 29.5 days: 360 degrees/29.5 = 12.2 degrees/day movement of the moon. Therefore, it takes the Earth (12.2/360) x 24 ~50 minutes to

orbital eccentricity

earth slowly changes from circular to elliptical orbit in ~100,000 years

what changes the angle that the sun hits the earth at different times of the year?

earth's rotation axis and orbit

human activities change ________, cause _______ and produce ______

ecosystems, extinctions, pollution

what do prefixes of clouds indicate?

elevation

insolation

energy from the sun

dune formation

eolian deposit, movement of sand is retarded by an obstacle and low pressure eddies result in deposition

loess

eolian deposit, silt-size, well sorted sediments, unstratified, strong cohesion

streams in deserts are

ephemeral

an _____ stream is one whose bed lies below the water table and in dry climates may sometimes become a _____ ______ or wadi

ephemeral, dry wash

an _______ stream is one whose bed lies below the water table and in dry climates may sometimes become a _______ or wadi.

ephemeral, dry wash

storms

episodes of severe weather - may be dangerous, bringing lightning, high winds, torrential rain, hail, sleet, snow

Abrasion

equivalent of sand-blasting

abrasion

equivalent of sand-blasting - can form potholes

superposed streams

erode through an unconformity but maintain the drainage pattern

how are ice ages recognized?

erratics - the observation of large boulders and non-local country rock being present in certain areas

drop stones

erratics in sediments from melting icebergs. Can show past glaciations by finding drop stones in marine sediments.

waterfalls

escarpments (elevated sections), sometimes caused by a change in base level, faulting, variations in rock type, are removed by erosion and migrate upstream (e.g., Niagara Falls).

fujita scale

estimates of wind speed based on the damage caused

______ form where river valleys have been flooded, whereas ______ form where glaciated ______ have been flooded.

estuaries, fjords, valleys

__________ form where river valleys have been flooded, wheres _____ form where glaciated _____ have been flooded

estuaries, fjords, valleys

submergent coasts

estuary, brackish water, fjord, headland and bay development

global sea level change

eustatic

can remove C from the system over time

evolution of life

much of the Earth's surface has been modified by human ______ and ________

excavations, agriculture

Much of the Earth's surface has been modified by human ____ and ____, and such activities chance ____, cause ____, and produce ____.

excavations, agriculture, ecosystems, extinctions, pollution

common water contaminants

excess sediment, sanitary and agricultural wastes, refined petroleum products, detergents, solvents, fertilizers, pesticides

Where are the winds strongest in a hurricane?

eye wall

Continental Slope

face of accretionary prism

controls the amount of solar radiation reaching the land surface and the ocean currents

factors of long-term climate change

rising water tables may initiate slope ____

failures

how does river "bendiness" affect velocity

fastest on outside of curves - further to travel

rectangular

faulted/jointed bedrock. Square patterns. 90-degree turns are common and streams enter each other at right angles

sediments = ____ _____ deposits

fine pelagic

subtropical, rain shadow, coastal, continental interior, polar region

five desert categories

Flood plain

flat area adjacent to river channel that periodically floods, with fertile soil

tidal flats

flat areas of mud/silt

abyssal plains

flat seafloor in deep water beyond the continental slope, -flattest place on earth - topology of the oceanic crust is fairly irregular, but sediments fill in irregularities

Fringing reef

flat, table-like reefs attached directly to the shore. The seaward edge is marked by a steep slope down into deeper water

fringing reefs

flat, table-like reefs attached directly to the shore. The seaward edged is marked by

flash floods

floodwaters rise so quickly it may be impossible to escape from their path

Flash floods

floodwaters rise so quickly it may be impossible to escape their path

fluctuation in solar radiation, changes in Earth's orbit and tilt, changes in volcanic emissions, changes in ocean currents, changes in surface albedo, abrupt changes in greenhouse gas concentration

fluctuation in Solar Radiation

alluvium

fluvial deposits

Alluvium

fluvial deposits that form where stream velocity drops below settling velocity

baymouth bars (barrier islands)

form as spits extend all the way across the mouths of bays

kame terrace

form in a similar manner to kames but between the lateral margin of a glacier and the valley wall

deltas

form when river enters a body of water and velocity decreases

subtropical deserts

form where convection cells diverge. Has very little water, which has condensed out after rising at the equator. Dense air mass moves to the equator with high evaporation rates as sinking dense air heats up. Found from 20-30 deg N and S latitude across geologic time

rapids

form where the stream flow is constricted - passing over large blocks, narrowing of the channel. This creates turbulence

increased volcanic activity can contribute to overall global warming. During Cretaceous, flood basalt formation occurred in the Pacific and Indian Oceans. CO2 content of the atmosphere increased - no ice caps.

formation of fossil fuels

coastal deserts

formed along cold costal currents. Cool air over cold ocean water holds little moisture. This air absorbs moisture when it interacts with land.

elongate: longitudinal/seif dunes

formed by converging winds, limited sand

longitudinal/seif dunes

formed by converging winds; limited sand

surface currents

formed by interaction of the sea with the atmosphere - subject to the Coriolis Effect

tombolo

formed by longshore currents when waves refract around an island and

capillary fringe

formed by surface tension and electrostatic attraction of water molecules to mineral surfaces which cause water to seep up from the water table

drainage network

formed by tributaries

speleotherms

formed when water trickles down cave walls or drips from the ceiling, re-enters air and releases some dissolved CO2. precipitates CaCO3 or travertine

permafrost regions cause problems for:

foundations, roadways, railroads, etc.

vertical erosion means the valley floor is generally ________

free of alluvium

Debris Fall

free-fall of regolith dominated material

why does velocity decrease at the ice margins?

friction with the substrate

wind movement

from high to low pressure

Pollution

from raw sewage, storm drain water in urban areas, spilled oil, industrial waste, excess fertilizers, animal waste, general trash. Can destroy or radically alter ecosystems and make rivers off-limits.

pollution

from raw sewage, storm drain water in urban areas, spilled oil, industrial waste, excess fertilizers, animal waste, general trash. Can destroy or radically alter ecosystems and make rivers off-limits.

acid rain

generated from sulfate-rich aerosols from coal-fired power plants; occurs downwind of major industrial cities

agency

geogenic vs. anthropogenic

Rock bolts

giant steel bolts driven into stable rocks below slip planes. Works best on thin slide blocks of coherent rocks on low-angle slopes.

what is the glacial equivalent of an eolian loess?

glacial loess - forms differently

rocks dragged over bed rock produce:

glacial striations, polished surfaces

glacial drift includes:

glacial till, erratics, glacial outwash, glacial marine sediments, loess, glacial lake-bed sediment

glacier retreats

glaciers always move _____ from zone of accumulation

biotic respiration, burning organic matter, metamorphism of carbonate rocks, degassing from the oceans

global cooling

sea level change can be ____ or _____

global, local

Halocline

gradational boundary between surface- water salinities and deep-water salinities.

rate

gradual v. catastrophic

what does wind erosion depend upon?

grain size and wind velocity

Traction

grains hopping/sliding along

bed load

grains rolling along the stream bed because stream velocity is less than the settling velocity of these particles. Typically sand and gravel

Bed load

grains rolling along the stream bed. typically gravel and sand.

traction

grains rolling/sliding along

what is glacial movement driven by?

gravity

what does groundwater respond to?

gravity and differences in pressure

convective lifting

ground warms the air and it rises, cooling adiabatically

how can permeability change over time?

groundwater could dissolve the aquifer constituents (increasing permeability), deposit material in the pores (decreasing permeability), pore spaces collapse due to over pumping

artesian well

groundwater is under enough pressure that it rises up the well sometimes to the surface. Requires a tilted, confined aquifer.

CaCO3

growth rings

stream migrates upstream through

headward erosion

fluvial deposition

heavy minerals deposited in rivers where velocity is low

cirro

high altitude (<7 km)

Divide

high area that separates drainage basins

divide

high area that separates drainage basins

upwelling coastal margins have ___ ____ of biological productivity

high rates

groundwater flows from regions of _____ to _____ hydraulic head/water table

high, low

Air starts to move from ____ pressure to ____ pressure regions and the ____ force modifies the flow direction.

high, low, Coriolis

nuclear power plants generate

high-level nuclear wastes

altitude

higher = cooler

a fold contains the _____ line, which is the intersection of a horizontal surface and the _____ plane

hinge, axial

A fold contains the ____ line, which is the intersection of a horizontal surface and the ____ plane; rock layers on either side of the latter are referred to as _____.

hinge, axial, limbs

A fold contains the ____ (a line along which curvature is greatest), the ____ (the sides of the fold that display less curvature), and ____ ____ (an imaginary plane that contains the hinges of successive layers).

hinge, limbs, axial plane

cooling event named after expansion of the arctic plant

holocene maximum

dendritic

homogeneous bedrock (igneous, metamorphic or sedimentary with horizontal bedding) not heavily faulted or jointed

Dendritic

homogeneous bedrock, not heavily faulted or jointed.

compression stress at convergent plate margins shortens the crust ______ and thickens it _______

horizontally, vertically

what describes a barchan sand dune?

horns point DOWNwind, bows point into the wind, limited sand

barchan dunes

horns point downwind, bows into wind; gentle slope into the wind, steep slip face on the inside of the arc; limited sand

crescentic: barchan dunes

horns point downwind, bows point into wind, limited sand

parabolic dunes

horns point upwind, bows downwind; shallow slope into wind; steep slip face on outside of the arc; forms around a blowout or deflation hollow; abundant sand

crescentic: parabolic dunes

horns point upwind, bows point downwind, abundant sand

geyser

hot spring that periodically erupts hot water and steam. Water seeps into geyser chamber and slowly warms. Bubbles form as temperature increases.

organic materials - trees and animals

how is carbon returned to the atmosphere?

what does the amount of insolation depend on?

how the sun rays hit the earth

sea-level changes

huge amounts of water become tied up on continents

groundwater is easily contaminated by ______

human activity

rainforest decline is largely the result of ____ _____

human agency

ecosystem modification

human changes occur faster than organisms can adapt, destabilizing established ecological balances and forcing certain species into extinction

can measure directly the CO2 content of

human history

beach dunes

hummocky, variable onshore/offshore winds, vegetation present

irregular/star: beach dunes

hummocky, variable onshore/offshore winds, vegetation present

what are hurricanes called in the atlantic?

hurricanes

coasts eroded by waves via:

hydraulic action, abrasion

sediment/nutrient flow downstream. Positive side - irrigation for agriculture,

hydroelectric (clean) power.

changes in surface albedo

ice caps reflect more radiation, promoting cooling. As glaciers melt, the land surface absorbs more heat and more melting occurs. Both are positive feedback mechanisms

proglacial lakes

ice dammed

ice shelves

ice entering the sea becomes a broad flat shelf

Glaciers entering the sea from continents form broad, flat shelves called:

ice shelves

fossil sand dunes

identify former sand dune environments by cross bedding, unconformity

tidal flat

if slope is gentle, a broad flat area is exposed at low tide

rock types

igneous, sedimentary, metamorphic

Why does discharge increase downstream in a temperate climate?

impact from tributaries and groundwater

aquitard (aquiclude)

impermeable bed (clay, shale, etc.)

-oxidation after death of organic matter, anoxic decay of organic matter and flatulence (CH4), burning of fossil fuels

important greenhouse gases

focusing effects of bays

in the open ocean, tidal reach is only a few meters, but a bay that narrows to a point brigs a large volume of water into a small area - Bay of Fundy, Canada, has a 20 m tidal reach

coral reefs

in warm water, associated with seamount; sunlight, shallow warm water, seamount provides the anchor

changes in volcanic emissions

increased volcanic emissions in the atmosphere changes Earth's albedo resulting in a diminishing of solar radiation reaching the surface

glacier has rocks frozen into the base which _____ the amount of erosion

increases

human greenhouse gas emissions have steadily increased since the start of the _____ _____

industrial revolution

human impact stems from exponential population growth aided by revolution in:

industry, agriculture, technology, and medicine, fueled by accessible natural resources

why does discharge decrease in arid climates?

infiltration and evaporation

Basin shape

influences wave motion, which can reinforce waves to increase the tidal reach, or cancel out waves to decrease the tidal reach

wave-cut notch

initially formed when waves undercut cliffs

Dissolved load

ions in solution

types of sand dunes

irregular, crescentic, elongate

CO2, CH4

is CO2 or CH4 a more efficient greenhouse gas?

if the aquifer/ground surface is not horizontal, a pressure differential ______

is set up

stack

isolated, pillar-like island detached from headland by wave erosion (i.e. erosional remnant of headland)

inselbergs

isolated, steep-sided erosional remnants that rise above desert plains

ways to stop beaches migrating/eroding, prevent cliff erosion, protect property values

jetties, breakwaters, groins, seawall

Regions where cave networks occur at or near the surface are ____ landscapes, with ____, natural ____, and disappearing ____

karst, sinkholes, bridges, streams

paternoster lakes

lakes formed by differential erosion down a valley

biosphere

land = vegetation, sea = chlorophyll production

emergent coasts

land surface rises, relative sea level drops:, waves break offshore, barriers, bars, lagoons forming, lagoons fill with sediment from streams, beach propagates seaward

human impacts

landscape modification, ecosystem modification

anvil clouds

large cumulonimbus clouds that flatten out at the tropopause

polynyas

large openings in sea ice

what are transgression/regression cycles bounded by?

large-scale unconformities

glacial subsidence

last ice age dropped sea level ~130 m

Till accumulates in ____ ____ along the side of a glacier, whereas ____ ____ form when two glaciers merge.

lateral moraines, medial moraines

types of moraine

lateral, medial, end, ground

glaciers can form at any ____ as long as _____ permits

latitude, altitude

factors controlling climate:

latitude, altitude, proximity of water, proximity to ocean currents, proximity to Orographic barriers, proximity to high or low pressure zones

salinity and seawater temperature vary with ____ and ____

latitude, depth

Factors such as ____, proximity to the ____, and ____ barriers affect local climate.

latitude, ocean, orographic

factors such as ___, proximity to the _____, and _____ barriers affect local climate

latitude, ocean, orthographic

Deserts form in a variety of areas including subtropical ____, ____ ____, coasts adjacent to ____ ____, the interiors of ____, and ____ ____.

latitudes, polar regions, cold currents, continents, rain shadows

Deserts form in a variety of areas including subtropical ______, _______, coasts adjacent to ______, the interiors of ______, and ______.

latitudes, rain shadows, cold currents, continents, polar regions

heterosphere

layered - heaviest at the base (N), then O, He, H

Sunspot activity spikes every 9-11.5 years; increased sunspots

lead to a decrease in solar output., Changes in the rate of cosmic radiation influx affect cloud formation., High-elevation clouds might reflect incoming radiation - cooling, but low-elevation clouds absorb infrared radiation reflected from surface - warming.

Strength

level of stress at failure in plastic materials

what happened when the ozone layer was thick enough?

life came out of the oceans

rock layers on either side of the axial plane are referred to as ____

limbs

non-toxic but unpleasant dissolved materials

lime, sulfur, salt, Fe

groundwater is an important influence on landscape development in areas with ____ _____

limestone bedrock

tillite

lithified till

what does the Earth system comprise?

lithosphere (solid Earth), atmosphere, and hydrosphere interacting with the biosphere

increased evaporation - middle east was fertile area. Vikings able to live in Greenland

little ice age

weather

local scale conditions defined by temperature, air pressure, relative humidity and wind speed

rip currents

localized undertow

flow velocities vary with _____ in a glacier

location

what are fjords called in Scotland?

lochs

continental interior deserts

long way from oceans, air has to rise from ocean and drops moisture close to the coast

drumlins

long, steep-sided hills of till; glacier overrode a moraine. The "bulb" points in the direction the glacier came from

written record, art, etc.

long-term climate change

mirage

look like distant water, result from light interacting with heated air just above the ground surface

changing albedo

loss of the Antarctic ice shelf means more of the suns rays are absorbed

kame

low, steep sided hill that was a sediment filled depression in the glacier

artificial levees

man-made (mud, sand, concrete).

well

man-made holes dug to access groundwater

wetlands in tropical/semitropical climates

mangrove swamps

mangrove swamps

mangrove trees survive in fresh and salt water because their roots can filter out salt

terminal

marks the farthest advance of the glacier

glacier

masses of ice formed on land and moving because of their weight and gravity

air pollution of the atmosphere

materials cycle through the atmosphere as they do the oceans; inert gases have an almost infinite residence time

Stream capacity

maximum load stream can carry. streams rarely carry to capacity.

stream competence

maximum particle size that it can carry

incised meanders

meandering channels that flow in steep, narrow, valleys

Hydraulic conductivity

measure of the ability of rock or soil to transmit water

climate warming reached a peak at 5000 to 6000 years ago

medieval warm period

wet-bottomed glaciers

meltwater at the base reduces friction. Melting occurs because of climate, heat flow, and/or pressure solution. End up with a slurry of material at the base of the glacier. Typifies temperate glacier movement

glacial lake sediments

meltwater streams carry fine particles away that settle out in meltwater lakes

alto

mid latitude

changes in Earth's orbit and tilt

milankovitch theory. cycles recorded in tills and from oceanic cores suggest wobbles every 23,000; 41,000 and 100,000 years

brackish water

mixing of denser salt water beneath freshwater

air

mixture of gases. Any volume of material feels a "buoyancy force"

stream velocity

moderate ~5km/h; flood >25km/h

proximity of water

moderating affect

1500-1800 C.E. - Thames froze over, as did the dikes in Netherlands

modern warming trend

effects of excavation, agriculture, construction

modify topography, drainage, infiltration, ecology; increase mass wasting

number of available conduits

more = greater permeability

older cliff retreat =

more irregular

desert pavement

mosaic of tightly fitting stones above a finer fraction that form a relatively smooth surface

proximity to orographic barriers

mountain ranges

wind

movement of air from high to low pressure

abrasion

movement of fine particles

dune formation

movement of sand is retarded by an obstacle (wind shadow) & low pressure eddies result in deposition, gentle slope windward; steep slip-face ~34 degrees leeward

Debris flow

mudflow is mixed with large rock fragments. Speed is dependent on slope angle and water content.

butte

narrow hill of resistant rock with flat top and steep sides, equally wide and tall

springs

natural groundwater outlets

natural levee

natural sediment build up that resists floods

Natural levee

natural sediment buildup that resists floods

rock

naturally occurring aggregate of two or more minerals

tornadoes

near vertical funnel-shaped cloud that funnels air up the center (low pressure). Rotates counterclockwise in the Northern Hemisphere

life initiation changed the atmosphere through CO2 removal. could have promoted the "snowball" Earth during the Proterozoic

negative feedback

what suffix/prefix do you add to clouds that produce precipitation?

nimbus/nimbo

on a plan within a rock body....

normal stresses tend to resist failure

proximity to ocean currents

north atlantic drift

movement throughout a glacier is _______

not constant

radioactive materials

nuclear weapons, nuclear energy, and medical waste transfer radioactive materials from rock to Earth's surface environment.

permeability depends on:

number of available conduits, size of conduits, straightness of conduits

catastrophic changes

occur because of catastrophic events. Whole species go extinct worldwide, reduces biodiversity

Weathering

occurs along joints/faults which breaks down the interlocking nature of minerals

what does oceanic crust form?

ocean basins

active margins contain ____

oceanic trench

where do submarine canyons form?

offshore from rivers

Submarine canyons

often form offshore from rivers. This may be because the channel may have been cut by the river when sea level was lower.

fulgurite

often tubular vitrified crust produced by the fusion of sand or rock by lightning

Reverse fault

older strata over younger. Hanging wall moves up relative to footwall (causes a repetition of strata)

Anticline

oldest rocks in the center, beds dip away from oldest rocks. If age of the rocks is unknown, it is called an antiform.

hurricanes

originate during summer/early fall in the Atlantic off Africa (latitude ~20 degrees N) over warm tropical water. IF water > 27 degrees C, a lot of moisture is in the air that rises and the latent heat of condensation promotes further rise and more moist air takes its place., coriolis effect causes the mass to rotate counterclockwise

what forms when meanders are cut off?

ox-bow lakes form

different species live in different climates, including plankton and pollen

oxygen isotopes

firn

packed granular snow produced by continual compaction

the stratigraphic record, paleontological evidence, oxygen isotopes, bubbles in ice, growth rings, human history

paleontological evidence

water table tends to ____ topography

parallel

water table tends to _______ topography

parallel

barrier reefs

parallel to the shore, but separated from it by wide deep lagoons; the lagoon has quiet waters as it is protected

Barrier Reef

parallel to the shore, but separated from it by wide, deep lagoons

channel "wanders" in the flood plain taking the ______

path of least resistance

piedmont

pediment + bajada

yardangs

perched rocks, pedestal formed by sand blasting (abrasion)

yardangs

perched rocks. pedestal formed by sand blasting (abrasion)

regions with snow cover (but not ice) and permafrost are usually ____ to ice caps

peripheral

pore collapse and land subsidence

permanent

permafrost

permanently frozen ground up to 1,500 m depth

what does rate of flow depend on?

permeability, hydraulic gradient

aquifer

permeable bed of rock or sediment that yields/contains water

elongate: transverse dunes

perpendicular to wind, steep slip face, abundant sand

transverse dunes

perpendicular to wind, steep slip face; abundant sand

what does the size of a wave depend on?

persistency of wind direction, wind velocity, and the distance (fetch) over which it blows

agriculture contamination

pesticides, herbicides, fertilizer, animal sewage

groundwater can percolate through buried wood and silica deposits, forming _____ _____

petrified wood

weather

physical conditions (temperature, pressure, moisture content, wind strength and direction)

weathering (Deserts)

physical weathering occurs along joints - expansion and contraction due to temperature changes. Lack of soil allows these blocks to build up (as TALUS) at the bottom of slopes and keeps bedrock exposed on slopes

Surface winds

pile water up at coasts - excess water sinks. If winds blow water away from coasts, water rises up to take the place of the surface water.

monument/chimney

pillar like spire of resistant rock with a flat top and steep sides, much taller than it is wide

Systematic joints

planar cracks that occur regularly throughout a rock body

living reservoirs

plants, animals, microbes

_____ ____ plays an important role in distribution of deserts on the continents

plate tectonics

which sequence of landforms goes from largest to smallest?

plateau --> mesa --> butte ---> monument

rock features of the southwest

plateaus, mesa, butte, monument/chimney

moulin

point at which a stream on the surface of a glacier disappears into it

where do inselbergs form?

pointed hills on Pediment

acid runoff

pollution from coal and base metal mining. Sulfide minerals in mined rock oxidizes to form sulfuric acid, which dissolves toxic metals and poisons waterways.

icehouse and greenhouse periods. There have been at least 5 major icehouse periods during Earth history

position of the continents

slows process down or reverses it; e.g. increase of CO2 increases global temperature, but also increases chemical weathering due to more precipitation (warm air holds more water), which removes CO2

positive feedback

elevation and pressure provide groundwater with

potential energy

lightning ____ the thunder clap

precede

what causes wind?

pressure and density changes

Breaking and lifting

pressure of flowing water can break rock fragments off the channel floor and walls. Flow an also cause clasts to rise/lift off the floor

breaking & lifting

pressure of flowing water can break rock fragments off the channel floor and walls. Flow can also cause clasts to rise/lift off the floor

how is the blue color of snow produced?

pressure solution of firn produces glacial ice with trapped air

deflation (other)

process of lowering the land surface

patterned ground

produced by freeze-thaw action. pushes cobbles into "walls" as expansion is not even

longshore drift

produced by movement

longshore currents

produced by refraction of waves

star dunes

produced if wind direction is variable

darcy's law states that discharge volume is ______ to the hydraulic gradient times the permeability

proportional

cumulus clouds

puffy, cotton-ball/cauliflower-shaped

remediating groundwater contamination

pump and treat, bioremediation, oxygenation

Remediation techniques used to clean up contaminated groundwater are ____ and ____, ____, ____, and ____ ____.

pump and treat, containment, bioremediation, source control

lagoon

quiet water between the barrier island and shore

Nonsystematic joints

randomly spaced with a variety of orientations

Permeability

rate at which fluids will move through a saturated material. determined by size and connectedness of voids and fluid properties.

whether a stream produces a canyon or valley depends upon?

rate of downcutting and the competence of the rocks forming the valley walls

how changes are described

rate, frequency, agency

relative humidity

ratio between the measured water content and the maximum amount of water the atmosphere can hold

Pennsylvanian (carboniferous)

records >30 shorter cycles (of sea-level transgression and regression) (cyclothems) that contain the coal measures, submergence-emergence

stratus clouds

relatively thin, stable layers (layered structure)

playa

remnants of temporary lakes

playas

remnants of temporary lakes. Salt encrusted clay deposits. Very flat! Salts include halite, gypsum, borax, etc.

Scouring

removal of loose fragments

scouring

removal of loose fragments

clouds

require condensation nucleii (aerosols)

Tensile Strength

resistance to failure under tensile stress, typically much lower than compressive strength, horizontal rock beams can be dangerous because of weak tensile strength

The stability of a slope reflects the relative magnitudes of ______ force and _____ force

resistance, downslope

mud flats

result from sediments filling in irregularities in the abyssal plains

mirages

result of light interacting with heated air just above the ground

undertow

return of water along sea floor

Methods to prevent/reduce mass wasting include _____ and _____ of slopes, as well as the installation of _____________ through impermeable barriers.

revegetation, regrading, water drain pipes

Methods to prevent/reduce mass wasting include ____ and ____ of slopes, as well as changing the ____ ____.

revegetation, regrading, water table

lateral moraine

ridge-like pile along the edge of a glacier

what does dune transport form

ripples

bergy bits

rise 1-5 m above the water, area = 100-200 m2.

growlers

rise less than a meter above the water

Flow folds

rock is soft and behaves like weak plastic. Develop because different parts of the body move at different rates

ventifacts

rocks shaped by wind blown sediments (angular)

Vegetation cover

roots bind loose regolith together and deforestation promotes instability.

contour currents

run parallel to the continental slope, not down it (follow the contours)

Contour currents

run parallel to the continental slope, not down it (follow the contours).

spits

sand deposits that form when longshore currents that move sand along the shoreline encounter deeper water in a bay and drop their sediment loads

dune transport

sand is blown up the gentle upwind slope

natural levees

sand ridges that parallel the channel

oceanography

scientific study of the oceans (e.g. topography of the ocean floor, compositions of the oceans, currents, asthenosphere-ocean interactions, etc.)

streams can _____ and _____ their beds and pick up sediment, which is carried as ______, ______, and ______ loads.

scour, abrade, bed, dissolved, suspended

barrier islands

scouring action of waves piles sand up offshore in a narrow ridge

where is air pressure the greatest?

sea level (14.7 lbs/in^2 or 1.035 g/cm^2 or 1 bar = 0.986 atm)

till

sediment carried or deposited by glaciers - unsorted and unstratified (immature). deposited beneath or at the toe of a glacier

glacial outwash

sediment deposited at the toe is picked up and redeposited by meltwater streams that sort the material; sand and gravel bars deposited by braided streams

Colluvium

sediment deposited by mass wasting. Poorly sorted, poorly stratified or unstratified

what is a bajada?

sediment deposits of coalesced alluvial fans

glacial drift

sediment derived from glaciation

Turbidity currents

sediment disperses into water forming a turbulent cloud of sediment that settles out to form graded bedded sediments

Braided streams

sediment load has exceeded stream capacity. Stream divides into numerous strands weaving between elongate mounds of sand an gravel

braided streams

sediment load has exceeded stream capacity. Stream divides into numerous strands weaving between elongate mounds of sand and gravel.

streams deposit their _____ load in _____ _____ at mountain fronts

sediment, alluvial fans

The ____ supply relative to the ____ rate determines if a beach grows, to form an ____ coast, or shrinks to form a ____ coast.

sediment, erosion, accretionary, rocky

what preserve evidence of sea-level change?

sedimentary rocks

how is sub-seafloor structure imaged?

seismic reflection

pelagic sediment

settles slowly through the ocean water and is made up of fine-grained clay and the skeletons of microscopic organisms.

Pelagic sediment

settles slowly through the ocean water and is made up of fine-grained clay and the skeletons of microscopic organisms., Includes muds - clay, silt from the continents, accumulated oozes

Liquefaction

shaking of wet sand causes grains to try and fit together more closely, which increases pore pressures, thus destroying cohesion and forming a slurry

waves in water with depth D < L/2 =

shallow water waves; feel the bottom topography:, wave orbits are forced to become elliptical, wave energy is confined to shallower depths

frictional resistance

shape of channel, perimeter roughness

arete

sharp ridge that separates valleys sculptured by glaciation

rocks can undergo three types of stress:

shear, compression, extension

what do streams begin as?

sheetwash

sea-level transgression

shorelines move landward, sea-level rises

sea-level regression

shorelines move seaward, sea-level falls

groins

short, artificial walls built perpendicular to the shoreline to trap sand moved by longshore currents.

makes a process continue or accelerate; e.g. runaway greenhouse effect on Venus

short-term climate change

>60%

short-term global climate change

banks

side of river channel

Banks

sides of river channel

Loess

silt-size, extensively well-sorted sediments, unstratified, cohesion strong due to fine grain size. Can reach >100 m thick

medial moraine

single long ridge of till on a glacier - formed when tributary glaciers merge (i.e., merging of lateral moraines to form one in the interior of the glacier).

evidence of groundwater

sinkholes

what does karst topography consist of?

sinkholes, disappearing streams, caves, natural bridges

esker

sinuous ridge of sediment deposited by glacial meltwater flowing within the glacier

climate has warmed since 1800 C.E.

six factors used to explain short-term climate change

a hydraulic gradient exists anywhere the water table has a ____

slope

velocity depends upon:

slope, thickness, temperature, friction along base & edges (depends upon shape)

downcutting > wall slumping forms a ________

slot canyon

Rock Glaciers

slow movement downhill of rock fragments and ice. Develop where debris volume falling into a valley exceeds ice accumulation

A ____ is a semi-coherent mass of material that moves downslope on a ____ surface.

slump, failure

tributaries

smaller streams joining the main or trunk stream

Tributaries

smaller streams joining the main trunk

smog

smoke + fog; urban haze created by the reaction of ground-level ozone and unburned hydrocarbons catalyzed by sunlight

proterozoic =

snowball earth - complete ice cover

unprotected fields

soil blown away during dry periods (e.g. dust bowl of the thirties) dust storm in Colorado stops 166,000 tons of dust on Kansas. Dust clouds up to 12,000 feet. Dust blocks out sun in New York City

how is ocean depth (bathymetry) measured?

sonar

Along coasts, sand can build sand ____, offshore bares, and ____ islands

spits, bars, barrier

along coasts, sand can build sand _______, offshore ________, and _______ islands.

spits, baymouth, barrier

light colored layers of varves

spring floods (silt)

the water table comes to the surface at _____, ________ & _____

springs, edges of streams, lakes

downcutting through alternate hard-soft layers produces a _____

stair-stepped canyon

what do speleotherms consist of?

stalactites, stalagmites, limestone columns

seamounts

steep sided volcanoes that rise abruptly from the seafloor, sometimes forming islands

beach face

steepest part of the beach

air pressure

storm surge can push high tides higher (hurricanes)

straightness of the conduits

straighter allows more efficient transport

what is the amount of deformation a rock experiences called?

strain

Hogback

strata are more steeply dipping so the mountain is more symmetric

______ drift is water sorted; ______ drift isn't

stratified, unstratified

tens to hundreds of thousands of years

stratigraphic record

geologists study the ____ record, _________ changes in ice and shells, and tree ________ to constrain the _________ and ________ of climate change

stratigraphic, isotopic, rings, character, timing

geologists study the ______ record, ______ changes in ice and shells, and tree ______ to constrain the ____ and _____ of climate change.

stratigraphic, isotopic, rings, timing, character

discharge =

stream cross section x average velocity of water downstream (Ac x va)

what is stream velocity a function of?

stream gradient, frictional resistance

antecedent streams

stream maintains its flow pattern during tectonic activity

equilibrium is slowly established as streams cut into the former surface, valleys widen, and hills erode. Eventually, the landscape is eroded to the new base level.

stream piracy

if base level drops and/or uplift occurs, streams cuts alluvium and forms _______

stream terraces

The overall ___ of a rock is not determined by its bulk ___ but by the ___ ___ principle

strength, properties, weakest link

Tensile stress

stresses of equal magnitude that act away from a point

Compressive Stress

stresses of equal magnitude that act toward a point from opposite directions

Shear stress

stresses that are offset from one another and act in opposite direction. (Acts parallel to plane)

Varying principle _____ during Triaxial experiments allows for the creation of multiple ______ that define the ______.

stresses, Mohr circles, failure envelope

varying principle ____ during Triaxial experiments allow for the creation of multiple ______ ______ that define the ______ ______

stresses, Mohr's Circle, failure envelope

beach

strip of sediment that extends from the low-water line inland to a cliff or zone of permanent vegetation

formation of tornadoes in the USA

strong upper level westerlies interact with strong southeast surface winds (Gulf moisture). Interaction produces shearing such that the air rotates in a horizontal cylinder, updrafts and one end and downdrafts at the other move the funnel vertical, initially white/grey clouds form, but when the funnel hits the ground, clouds become black due to entrained debris

Aseismic ridges

submarine ridges with no earthquake activity aligned seamounts or guyots

Guyots

submerged flat-topped seamount 1,000 - 1,700 meters below the surface.

what do eustatic sea-level changes produce?

submergent (drowned) coasts and emergent coasts

five categories of deserts

subtropical, rain shadow, coastal, continental interior, polar regions

abrupt changes in greenhouse gas concentration

sudden release of methane hydrates from oceanic sediments due to sea level drop. Changes in amount of photosynthesizers can alter CO2 levels

solar output varies with the sunspot cycle (magnetic storms on the sun's surface)

sunspot cycle

physical cycles

supercontinent cycle, sea-level cycles (cyclothems), rock cycle

what does the type of runoff depend on

surface roughness and flow velocity

water table

surface that is the contact between saturated and unsaturated zones

ekman spiral

surface winds drive surface currents, and each layer of water drags the layer below, but the Coriolis Force changes each layer's direction slightly to make a spiral effect, (deflects each deeper layer 45 degrees from the one above)

hyporheic zone

surface/groundwater exchange

glaciers can speed up and slow down. If water builds up beneath a glacier it can undergo a ___ until the water is released

surge

types of clastic loads

suspended & bed loads

when grains are < 0.2 mm:

suspended (dust storms)

wetlands in temperate climates

swamps, marshes, bogs

hogback

symmetric ridge developed due to steeply dipping strata

Rocks formed through mass wasting and collect at the bottom of slopes are called

talus

Erosional debris forms at the base of cliffs as ____; sediment transported by _____ ____ accumulates in ____ ____ at the mouths of _____.

talus, flash floods, alluvial fans, canyons

Erosional debris forms at the base of cliffs as _____; sediment transported by ______ accumulates in _____ at the mouths of _____.

talus, flash floods, alluvial fans, canyons

local sea-level changed produced by:

tectonic uplift along a subduction zone or local isostatic rebound

Mesosphere

temperature decreases to -85 degrees C from 47 km to 82 km as this layer doesn't absorb solar radiation. Meteors start to burn up in this layer.

temperate glaciers

temperature is at or near to the melting point of ice for a substantial portion of the year.

polar glaciers

temperature is below freezing year round

sea ice

temperature low enough for sea to freeze (North pole). sea ice is currently shrinking

stratosphere

temperature stays the same for ~10 km then increases to ~0 degrees C at ~47 km. This layer doesn't convect. Heating occurs because O3 absorbs solar radiation

Type of deformation dependent on:

temperature, pressure, deformation rate, composition, depth., Generally, ductile is deeper. Brittle causes earthquakes.

what is the quantity of dissolved ions in groundwater controlled by?

temperature, pressure, pH

end moraine

terminal and recessional periods - both represent periods of glacial stagnation

what does convection in the troposphere produce?

the Hadley, Ferrel and Polar Cells, that are offset by the rotation of the planet

_____ extends into the ocean basin

the abyssal plain

recharge

the area where water enters an aquifer system

one rock type may transform into any other rock type -

the atoms in rocks are constantly being rearranged

climate changes lasting centuries to hundreds of thousands of years

the climate record of the Pleistocene (2.5 m.y.) indicates that continental glaciers have advanced and retreated ________ times in the northern hemisphere based on evidence from ____, _____, and _____

permeability

the ease of water flow due to pore inter-connectedness

sea-level cycles

the eustatic sea-level has risen and fallen many times over Earth's history

what do tides result from?

the gravitational attractions of the moon and sun acting on the rotating earth

kettle lake

the kettle is filled with water

main tidal forces caused by _____

the moon

in mid-latitudes, what does the weather usually reflect?

the movement of a large low-pressure air mass (moving west to east)

the hydrologic cycle

the movement of water through the biosphere

Submarine debris flows

the moving mass breaks apart to form a slurry containing larger clasts (pebbles to boulders) in a mud matrix

potentiometric surface

the natural level of the water in the confined aquifer. If this is below ground level, there will be a non-flowing artesian well.

how does the boiling point of water increase in a geyser?

the neck may become clogged which increases pressure

hydraulic head

the potential energy available to drive the flow of a given volume of groundwater at a location

settling velocity

the rate at which suspended solids subside and deposit

backwash

the retreat of water back down the beach

when negative and positive charges meet, what carries positive charges up to the cloud?

the return stroke

if an aquifer is horizontal and the ground surface is flat, pressure on the water is _____ at any place

the same

storm surge

the side of a hurricane where winds blow onshore piles up the sea over a 60-80 km region and pushes it on land (e.g. Katrina)

trunk stream

the single larger stream into which an array of tributaries flow

deflation

the sorting out, lifting, and removal of loose, dry, fine particles by turbulent eddy action of a fluid

nature of sediments (continental, marine, coal, cross-bedded sandstones)

the study of paleoclimate is conducted by:

what happens when it rains or the dew is heavy (playas and salt lakes)

the surface becomes slippery - rocks can be blown over the surface

upwelling

the upward movement of ocean water toward the surface as a result of offshore wind pushing water away from the shore

porosity

the volume of open spaces in rock or soil

groundwater

the water that fills pore spaces and fractures below ground level

what does the greenhouse gas effect operate in a similar manner to?

the way glass traps heat in a horticultural greenhouse

changes in ocean currents

the younger dryas may have occurred because a layer of freshwater from melting glaciers spread out over the North Atlantic and prevented thermohaline circulation, shutting off the Gulf Stream

what is the prefix for clouds at low atmosphere?

there isn't one

Hot pools can be multi-colored depending on the type of __________ _____-________ that metabolize the sulfur emitted by or contained in the hot spring.

thermophilic cyano-bacteria

identify the false statement. mountains don't get infinitely high or exist forever because:

they are eventually subducted in the plate tectonic cycle

how to positive ions flow upward to the cloud (lightening)

through conducting materials: trees, buildings

Stream load

total material that the river is carrying

where does the water flow fastest and deepest in a curved channel?

towards the outer edge of the stream over the thalweg

when grains are > 0.2 mm:

traction - rolling, bouncing along ground, saltation - jumping to about 5' above the ground (sand storms)

prevailing surface winds

trades or westerlies; polar easterlies > 60 degrees

elongate dunes

transverse dunes, longitudinal/seif dunes

Yazoo streams

tributary streams that run in the floodplain parallel to the main river. Blocked from doing main stream by natural levees

yazoo streams

tributary streams that run in the floodplain parallel to the main river. blocked from joining the main river by natural levees

most erosion is caused on the ocean floor by ____

turbidity currents

what are hurricanes called in the pacific?

typhoons

dunes

typically a few meters high, but can be 200m by 100m

Suspended load

typically clay and silt. Remain suspended because stream velocity exceeds settling velocity of the particles.

suspended load

typically clay and silt. Remain suspended because stream velocity exceeds the settling velocity of the particles.

sheetwash

unchanneled sheet of water, especially in deserts (no vegetation)

Sheetwash

unchanneled sheet of water, especially in deserts (no water)

where does ground water flow?

underground

frequency

unidirectional vs. cyclic

moraine

unit of till carried or deposited by the glacier

environmental aspects of wind

unprotected fields -> dust bowl, changing climates -> desertification, violent storms, wind power

troposphere

up to 9 km at the poles and 12 km at the equator. Temperature decreases to ~-55 degrees C. Base is heated by infrared radiation causing convection, which causes the weather.

position of the continents, volcanic activity, uplift of land surface, formation of fossil fuels, evolution of life

uplift of land surface

cirque

upper part of u-shaped valley where glacier originated; basically a feature formed at the head of the glacier. has 3 steep sides, often with a lake or tarn in it

Lack of vegetation in deserts means?

variation in bedrock color stand out - variations in the amount of Fe and/or the amount of oxidation, ex: Painted desert, N. Arizona, Petrified Forest National Park

Wobble's of Earth's orbit

variations in the Earth's orbit and inclination to the Sun. The Earth's rotational axis is precessing - this may trigger ice ages.

during the phanerozoic, oxygen composition ______

varied

seawater temperature

varies with latitude and depth (like salinity)

coastal wetlands

vegetated, flat-lying stretch of coast that floods with tides, but does not experience wave action

critical velocity

velocity of fluid flow at which flow changes from laminar to turbulent. In comparison, water can move large material with lower velocity

stream gradient

vertical distance/horizontal distance. Given as m/km or %

tide

vertical movement of sea level

Tides

vertical movement of sea level.

When a river's gradient is steep, erosion is ____, whereas when the gradient is gentle, erosion is ____ and ____ form along the river course

vertical, lateral, meanders

Debris avalanche

very rapidly moving, turbulent mass of debris, rock and water.

Exposes more land to chemical weathering. This absorbs CO2 and can reduce the atmospheric concentration. This may have triggered the Cenozoic cooling that led to the Pleistocene ice age.

volcanic activity

radial

volcanoes and domes

discharge

volume of water flowing through a given point in a stream in unit time

frontal lifting

warm air rises over cold.

What happens when a warm front moves in?

warm air slowly rises over the cool air and clouds form because a warm front has a gentler slope than a cold front

collision & convergence

warm clouds, tiny droplets collide and stick to form larger drops until they are too large to remain suspended. If the air below is cold, it falls as sleet

any process that increases the amount of greenhouse gases:

warms the atmosphere

nuclear materials from mining and processing generate:

waste mine spoil, mill tailings

Mass _______ can occur because fractured and weathered ________ and _______ are both relatively weak.

wasting, rock, regolith

what is the dominant force shaping desert landscapes?

water

Dissolution

water dissolves soluble components

dissolution

water dissolves soluble components

thermal springs

water heated to 30-100 degrees celsius by magma or hot rock beneath the surface

what does groundwater form through?

water infiltration into the subsurface; some evaporates, some is taken up by plants, some wets the surfaces of particles, some percolates to the water table

why can water move larger material with lower velocity?(efficiency)

water is more dense, restricted to a certain volume

wave motion

water is moving in an orbit, wave propagation is moving energy forward, not the water mass

Turbulent flow

water moves along an erratic path, deflected by the sides and bed of the channel (and obstructions) with the formation of eddies and swirls

turbulent

water moves along an erratic path, deflected by the sides and bed of the channel (and obstructions) with the formation of eddies and swirls (shearing motion)

niagara falls

water moves from Lake Erie to Lake Ontario. Drops over a 55 m ledge of hard Silurian dolostone, which is on top of weak shale. Undercutting by the water as it falls (forming a plunge pool) cause migration

laminar

water moves slowly along a smooth channel, following straight parallel lines, follows slope of containing boundary. More friction in wider, shallower streams

Laminar Flow

water moves slowly along a smooth channel, following straight, parallel lines, follows slope of containing boundary. More friction in wider, more shallow streams

Overuse

water taken out of rivers can mean none reaches downstream

overuse

water taken out of rivers can mean none reaches downstream (e.g., Aral Sea in Central Asia).

what can pores be filled with?

water, air, mineral cement, oil, natural gas

what does counterclockwise moving air create?

wave cyclone

berm

wave-deposited platform that is nearly flat - deposited above the usual high water line due to storms

swash

waves break and surge up the beach

radioactive waste contamination

weapons manufacture, hospitals, spent fuel disposal

bajada

wedge of sediment along a mountain front formed by calescence of alluvial fans

in what direction do hurricanes move in the atlantic?

west - winds on the N-side are relatively faster than those on the S-side

flood control measures

wetlands (nature's sponges), floodways (areas kept clear of building and development as they will be inundated during flood to reduce the volume of water in the channel), move levees further away so they don't have to be so high.

marshes

wetlands dominated by grasses

bogs

wetlands dominated by moss and shrubs

swamps

wetlands dominated by trees

Flood control measures

wetlands, floodways, moving levees further away

headward erosion allows one stream to "capture" another.

what can stream piracy cause?

area evaporation & melting, "calving" of icebergs.

what does the position of the toe represent?

Flexural folds

when a stack of layers bends, slip occurs between the layers

truncated spurs

when aretes are truncated by u shaped valleys

calcrete

when calcite dissolves, this deposits bc it cements loose grains together

inselbergs

when cliff retreat happens on all sides and produces islands of rocks or pointed hills on a pediment

occluded front

when cold fronts moving faster than warm fronts overtake them and lift up the base of the warm front so that it is no longer in contact with the ground.

a drainage reversal

when do floods happen?

when do fluvial deposits/alluvium form?

when stream velocity drops below setting velocity

when is alluvium deposited?

when the base-level is reached or it rises

when does sediment erode quickly?

when torrential rains generate flash floods characterized by rapid flow of thick, muddy, and viscous water.

channel flow

where a rive/stream is most of the time.

Chanel Flow

where a river/stream is most of the time

mudpots

where boiling water mixes with volcanic ash. The ash changes to clay and forms a hot, muddy soup

CH4

where is carbon stored when it is removed from the cycle for long periods of time?

in limestones, fossil fuels (coal and oil), organic shales, and methane hydrates

where is carbon stored when it is removed from the cycle for short periods of time?

coast

where land and sea meet

divergence zone

where limbs of the hadley, ferrel and polar cells fall due to cooling

convergence zone

where limbs of the hadley, ferrel and polar cells rise due to heating

where are tidal bulges produced

where moon's gravity is the strongest and weakest (closest and furthest from the moon)

Mouth

where the river enters a larger body of water

mouth

where the river enters a larger body of water (ocean, lake, etc)

Channel

where the water flows during non-flood stages

channel

where the water flows during non-flood stages

Springs

where the water table and ground surface intersect.

springs

where the water table and the ground surface intersect

where does wave refraction occur?

where the wave enters the shallow water obliquely

what are waves generated by?

wind

hurricane damage is caused by:

wind, waves, rainfall (flooding and associated mass wasting), storm surge

desert varnish

wind-borne dust settles on rocks. When dew precipitates, bacteria metabolize these particles and deposit Fe- and Mn-oxides. Takes a long time to form, but native americans made use of it for artwork (petroglyphs)

dark colored layers of varves

winter lake is frozen over and water is still (clay + organics because of death)

cirrus

wispy shape

ungraded

young streams - irregular with rapids and waterfalls

20-30, fossils, sediments, isotopes

younger dryas

-highlands

zone of ablation

ice flows from the _______ to the _____

zone of accumulation, toe

eye of the hurricane

zone of relative calm

proximity to high or low pressure zones

zones of divergence or convergence

distribution of deserts

zones of high pressure at ~30 degrees N & S, as well as 90 degrees N and S. Also leeward sides of mountains

how long ago did the most recent ice age end?

~10,000 years