Test 4 Flashcards
Divergent tectonic plates have _____ volume, _____ eruptions
high volume, gentle
Convergent tectonic plates have ____ volume, _____, ____ eruptions
low volume, periodic, violent
What are “Hot Spots”?
Volcanic activity in the interior of a tectonic plate
What is a rising plume of hot mantle material that is stationary?
A hot spot
When Oceanic crust is involved, a hot spot creates what?
Constant, high volume, gentle eruptions
When a continental crust is involved, a hot spot creates what?
Very periodic eruptions, extremely violent
Yellowstone National Park is a _____ crust volcano
continental
Hawaii is a _____ crust volcano
oceanic
What is the term for stuff that comes out of a volcano?
Ejecta
What are the 4 gases that come out of a volcano?
Steam, Sulfur gases, acidic gases, carbon gases
What are the 3 things that come out of a volcano?
Gases, liquids, pyroclastics
wHAT ARE THE TWO FORMS OF LAVA?
Pahoehoe and Aa
What are the characteristics of Pahoehoe lava?
Low viscosity and a smooth, ropy appearance
What are the characteristics of Aa lava?
High viscosity, broken, jagged appearance
What is the composition of Felsic lava?
Rhyolitic, >65% silicon, very viscous, Aa only, high gas content, explosive eruption
What is the composition of Intermediate lava?
Andesitic, 55-65% silicon, Medium viscosity, Aa only, medium gas content, medium eruption
What is the composition of mafic lava?
Basalitic, 45-55% silicon, low viscosity, pahoehoe or Aa, low gas content, gentle eruption
What controls viscosity?
silica
What controls gas content?
viscosity
What controls explosion?
gas content
What are pyroclastics?
solids released during an eruption
What are the sizes of pyroclastics?
dust, ash, lapilli, bombs
Volcanic dust is composed of what?
clay and silt
What can alter climate?
volcanic dust
What size is ash?
sand-sized
What is lapilli?
gravel-sized cinders
What are the 4 types of volcanoes?
Shield, composite, cinder cone, lava dome
What are the characteristics of a shield volcano?
Broad, gently sloping, constructed of repeated lava flow, low viscosity, very runny.
What are the characteristics of a composite volcano?
tall, steep sloped volcano, composted of alternating layers of pyroclastics and lava flows
What are the characteristics of cinder cone volcanoes?
small, steep-sided, grows on sides of bigger volcanoes, made entirely of pyroclastics, single eruptions flowing out of base,
What are the characteristics of a lava dome?
build-up of viscous lava around a vent that expands outward like a balloon.
What are the 4 volcanic hazards?
Lava flow, ash fall, pyroclastic flow, Lahar
What is lahar?
Mixture of pyroclastics and water that flows down the volcano
How many volcanoes does the US have within it’s borders?
108
What is weathering?
Breakdown and decomposition of rock and minerals at the earth’s surface through physical and chemical processes
What are the two categories of weathering?
Mechanical and chemical
What is mechanical weathering?
Physical processes that break up minerals and rocks into smaller pieces by applying a force
What is chemical weathering?
Decomposition of rocks through chemical reactions
What does chemical weathering require?
liquid water
What is oxidation?
when a mineral reacts with oxygen dissolved in water
Biological weathering is sometimes not included as a separate weathering category. Why is that?
Plants and animals are agents of mechanical and chemical weathering
What are the three products of weathering?
1) Reduction in grain size
2) Creation of new minerals
3) Soil
What is regolith?
Loose mineral and rock fragments in situ (in place)
What is sediment?
regolith that has been transported by surface processes
What kind of new minerals does weathering create?
oxides and clay minerals
What kind of clay minerals does weathering create?
sheet silicates with clay-sized crystals
What is soil?
complex mixture of mineral and organic material, liquids, and gases
What forms a thin veneer on the earth’s surface?
soil
What is soil made of?
25% air, 45% minerals, 25% water, 5% organic material
What are the factors of soil formation?
Parent material, climate, topography, living organisms, time
what is a kame
irregular conic shaped hill formed by topographic inversion, low areas/holes in ice that have filled with sediment
what is a kettle
irregular circular depression from topographic inversion, melting of an iceblock
what is a crest
high part of a wave
what is a trough
low part of a wave
what is wave length
distance between similar parts of adjacent waves
what is wave heigt
difference between a crest and a trough
oscillatory motion
path the water/particles in wave travel, rolling cirular motion
what is the wave base
depth below which water is not disturbed by a wave, about 1/2 wavelength
what are the controls on wave height
wind speed, duration of the wind, fetch
what is fetch
length over which a wave can grow
What does time influence?
thickness of the soil, accumulation of weathering products, horizon development
what is wave refraction
bending of wave fronts as they come into shore
what does wave refraction create
long shore current
what is the long shore current
weak current parellel to shore
what is long shore drift
movement of sediment w/ wave activity, parallel to shore
what is a rip current
this is where a long shore current moves off shore
what is a tide
local fluctuation in sea level caused by the gravitational pull of the sun and the moon
what are the 2 bulges
solar and lunar
explain what a spring tide looks like
solar and lunar bulges are aligned, occurs at new moon and full moon, highest high tides, lowest low tide
explain what a neap tide looks lik
solar and lunar bulges are perpendicular, 1/4 moon and 3/4 moon, lowest high tide, highest low tide
what is a beach
accumulation of loose material on a shoreline
put the zones of a beach in order from furthest inland to furthest away from land
coast line, backshore, foreshore, nearshore, offshore
what are characteristics of the coast line
wave activity has no influence, cliffs, bluffs, dune, vegetation
what are characteristics of the backshore
not washed by normal wave activity, periodic activity
what are charactersits of the foreshore
exposed during low tide, washed by high tide
what are characteristics of nearshore
always submerged, within wave base
what are characteristics of offshore
submerged 24/7, deeper than wave base, no impact of normal wave activity
what are berms
erosional scarp/ridge that marks the highest extend of wave activity, slope back toward coast
what is a beach face
slopes seaward/lakeward, washed by activity
what is the longshore bar
slight rise in sea/lake bed, submerged
what is a spit
long shore current extends the beach partially across and indentation in the coast, peninsula of sediment
what is a bay mouth bar
sip that has gown completely across and indentation in coast
what is a tombolo
an accumulation of sediment behind break waters
what is a barrier island
long, low island oriented parallel to shore
when wave energy increases speed of water does what
goes up
storage=
inputs-outputs
what are inputs of sediment
streams, longshore drift, erosion on cliffs and rocks
what are outputs of sediment
seaward/lakeward movement, landward movement, longshore drift
what are factors that induce beach erosion
sea level rise, dam a river or a stream, interfere with longshore drift/current w our structures
what are some solutions to beach erosion
shore parallel structures, shore perpendicular structures, beach nourishment
What is parent material?
Regolith/sediment a soil forms or develops in
What does parent material influence?
starting grain size and composition, porosity and permeability
What is porosity and permeability controlled by?
grain size
What is permeability?
Ability of a soil to transmit a fluid
What is climate?
Average temperatures and precipitation patterns
What does climate influence?
abundance and diversity of living organisms in an area, rate and type of weathering
What controls the rate of chemical reactions?
temperature
What is Topography?
Shape of the land surface
What does topography influence?
Drainage, rate of erosion and deposition
What do living organisms influence?
biological weathering, fertility
What does time influence?
thickness of the soil, accumulation of weathering products, horizon development
What are the 5 properties used to describe soils?
color, humus, soil texture, soil structure, pH
What does color tell us about the soil?
It’s composition, degree of weathering
What do we use to determine soil color?
Musell color system
What is the hue?
Actual color (page in the book)
what are characteristics of the r horizon
bed rock
What is value?
lightness/darkness
What is humus content?
Chemically stable decomposed organic material
What does Humus do to the color of soil?
darkens it
What does soil texture mean?
relative proportions of sand, silt, and clay
What is soil structure?
Soil particles bond together in aggregates of distinctive shapes
What is pH?
Concentration of the H+ ion in a substance
Most soils are between what pH?
3 and 9
What is soil profile?
description of the vertical structure of a soil
What are horizons?
layers in soil
What are the two top soil horizons?
O horizon and A horizon
The physical properties of the O horizon are determined by what?
organic material
The physical properties of the A horizon are determined by what?
mineral material
What horizons are in the subsoil?
E Horizon and B horizon
What dominates the E horizon?
Minerals
what are soil properties
color, humus, soil texutre, soil structure, pH
what is pH
chemically stable decomposed organic material, darkens color, fertility and water
what is soil texture
relative proportions of sand, silt, and clay, use textural triangle
what is soil structure
soil particles bond or stick together into aggregations of distinctive shapes
what is soil profile
description of the vertical structure of a soil, changes with depth
what is a meander scar
abandoned stream channel that is dry/wetland
what is in the master horizon
top soil (o and a), sub soil (e and b)
what horizons are in the top soil
o and a
what horizons are in sub soil
e and b
what are characteristics of o horizon
dominated by organic material, organic material at various stages of decay, dark in color, fluffy, easily lost to erosion
what are characteristics of a horizon
dominated by mineral materials, mixture of mineral and organic materials, washed of small and soluble minerals, dark in color with a granular structure
what are characteristics of e horizon
mineral dominated horizon, no organic material, leached of small and soluble minerals, light in color and platy structure
what are the characteristics of the b horizon
accumulation of minerals from above, clay rich, brightly colored, blocky structure,
what 2 horizons are in the parent material horizon
c horizon, r horizon
what are characteristics of c horizon
mineral dominated, regolith or sediment, some evidence of weathering
what are characteristics of the r horizon
bed rock
what are streams
channelized flow of water on the earth’s surface regardless of size
stream ordering
rank streams in a network according to importance
what is a drainage basin
area of land that contributes water to a give stream/network
what is a drainage divide
topographically high area that separates one drainage basin from another
what is stream flow
redistribute precipitation around landscape by moving water
what is discharge
volume of water passing through a given cross section of stream per unit time
gage height
height of water surface of a stream above a known elevation
what are stages of stream flow
normal stage, bank full, flood stage
what are the types of sediment loads
bed load, suspended load, dissolved load
what is a bed load
rolling, sliding or jumping along bottom
suspended load
carried in water column, smaller materials
medial moraine
where two glaciers come together
what is competence
size of the largest particle a stream can carry, controlled by velocity
what moraines are associated with continental glacial environment
all end moraines perpendicular to ice flow
what are the types of channels
straight, meandering, braided
what is a cut bank
erosional scarp on the outside of a meander bend
what is a point bar
accumulation of sediment on the inside of a meander bend
what is a natural levee
accumulation of sediment forming a low ridge parallel to the stream channel
what is a flood plain
flat area adjacent to stream channel that is covered during a flood
what is a meander scar
abandoned stream channel that is dry/wetland
what is an oxbow lake
abandonded stream channel that contains water
what is a terrace
abandoned flood plain, “step”
what is a glacier
mass of ice and snow that flows under its own weight
what are types of small glaciers
cirque, valley, tide water, piedmont
what is a cirque glacier
confined to bowl shaped depression
what is a valley glacier
glacier is confined to a valley in the mountains
what is a tide water glacier
valley glacier that ends in the ocean
what is a piedmont glacier
when a valley glacier glows outside the end of a valley it spreads out into a large fan/lobe
what are the types of large glaciers
ice cap/ice sheet
what is mass balance
ice and snow budget of glacier, accumulation - ablation
what are processes that add mass to a glacier
precipitation, deposition, avalanche
what are the processes that remove mass from a glacier
melting, sublimation, calving (blocks break off into water)
what is the equilibrium line
where accumulation and ablation are equal
what is an alpine glacier environment
glaciated mountains, small glacier, topographic inversion is mineral
what is a cirque
bowl shaped depression found near tops of mountains at head of glacial valleys
glacial trough
u shaped valley created by glacial erosions
horn
pyramid shaped mountain peak created by erosion of multiple glaciers
arete
knife like ridge
moraine
depositional feature, ridge of sediment accumulated by a glacier
end moraine
across front of glacier, perpendicular to glacial flow
lateral morain
accumulation of sediment along sides of glacier
medial moraine
where two glaciers come together
what is a continental glacial environment
large glaciers, topographic inversion common
what moraines are associated with continental glacial environment
all end moraines perpendicular to ice flow
what is a drumlin
streamlined hill formed beneath a glacier
what is an esker
sinous ridge of sediment formed beneath a glacier, topographic inversion, in filling of meltwater tunnels or channels in ice
The E horizon has no _____ and is leached of small and soluble _____
organic material, soluble minerals
What color and structure does the E horizon have?
light in color and platy structure
The B horizon is ______ dominated
mineral
The B horizon accumulates minerals from where?
above
The B horizon is ____-rich, ____ colored, and has a ____ structure
clay, brightly, blocky
The parent material horizons include what?
C and R Horizons
The C horizon is the ____ horizon
mineral
The C Horizon is made up of ____ or sediment
regolith
There may be some evidence of _____ in the C horizon
weathering
The R horizon is _____.
bedrock
What is a stream?
A channelized flow of water on the earth’s surface regardless of size
Streams are arranged on the landscape into a _____
network
What is a stream pattern determined by?
The underlying rock type and underlying geological structure
In stream ordering, the ____ the number, the more important the stream
higher
What does stream ordering do?
Allows us to compare streams within a network and between two different networks
Step one in stream ordering is:
Any stream within the network that has no tributaries is given rank 1
Step two in stream ordering is:
If two streams have the same rank, the converging stream goes up one order. If they have different ranks, keep the higher number
What is a drainage basin?
An area of land that contributes water to a given stream or stream network
What is a drainage divide?
Topographically high area that separates one drainage basin from another
What is stream flow?
re-distributes precipitation around the landscape by moving water
What is velocity?
speed of water
What is velocity primarily controlled by
slope of stream bed
What is discharge?
Volume of water passing through a given section of stream per unit time
What is gage height?
Height of the water surface of a stream above a known elevation
What is a stage?
characterizes stream flow relative to channel
What are the three stages of gage height?
Normal, bank full, and flood
In normal stage, where is the water?
within the channel
In bank full, where is the water?
completely filling the channel
In flood stage, where is the water?
water overtops and spreads out
What is the other job of streams?
Sediment load
What is sediment load?
sediment moved with streamflow
What are the three parts of sediment load?
Bed load, suspended load, dissolved load
What is bed load?
Rolling, sliding, or jumping along the bottom of larger materials
What is suspended load?
Material being carried in the water column
What is dissolved load?
Ions in solutions
What is competence?
Size of the largest particle the stream can carry
What is competence controlled by?
velocity
What is capacity?
total mass or volume of sediment being moved by the stream
What is capacity controlled by?
discharge
What is a channel?
Low-lying area where the water flows
What are the types of channels?
straight channels, meandering channels, braided channels
Where are straight channels found?
In areas with very steep slopes
Where are meandering channels found?
down stream near the mouth
braided channels have a _____ load
high sediment load
What is a thalweg?
path of highest velocity water in a stream. High erosion area
What is a cut bank?
Erosional scarp on the outside of a meander bend
What is a point bar?
An accumulation of sediment on the inside of a meander bend
What are natural levees?
Accumulation of sediment forming a low ridge parallel to the stream channel during floods
What is a glacier?
mass of ice and snow that flows under it’s own weight
How does a glacier move?
slides on it’s base or from a deformation of ice crystals
What are the 3 functions of glaciers?
re-distributes water around landscape, forms networks, and moves massive amounts of sediment
What are the two types of glaciers?
Large and small
Small glaciers shape and flow is controlled by what?
the underlying landscape
What are the two types of small glaciers?
cirque and valley glaciers
What is a cirque glacier?
A glacier that is confined to a bowl0shaped depression near the top of a mountain
What is a valley glacier?
A glacier that is confined to the valley in mountains
What is a tidewater glacier?
Valley glacier that terminates in the ocean
What is a Piedmont glacier?
When a valley glacier flows outside the end of a valley and spreads into a large lobe
What are the two types of large glaciers?
Ice caps and Ice sheets
What is the flow and shape of large glaciers controlled by?
the dynamics of the glacier
Ice caps are how big?
<50000 km^2
Ice sheets are how big?
> 50000 km^2
Mass balance =
accumulation-ablation
What is accumulation?
gains of ice and snow
What are three ways that accumulation can happen?
precipitation, deposition, avalanche
What is ablation?
losses of ice and snow
How can ablation occur?
melting, sublimation, calving
At the top of a mountain, accumulation _____ ablation
is more than
The top of a mountain is known as the _______
accumulation zone
In the middle of a mountain, accumulation ____ ablation
is equal to
The middle of the mountain is known as the ______
equilibrium line
The lower part of the mountain and glacier is known as the ______
ablation zone
Ice always flows from the _____ to the _____
accumulation to the ablation zone
In a large glacier, where is the accumulation zone?
In the middle
What is the annual mass balance?
Over a year, the relationship between accumulation and ablation for the entire glacier
What is annual mass balance tracked with?
climate
What is the alpine glacier environment?
glaciated mountains, result of small glaciers eroding the landscape
Topographic inversion is ______ in alpine glacier environments
minimal
In topographic inversion, high areas on the glacier result in _____ on the landscape, whereas low areas result in what?
low areas, high areas
What are the features of alpine glacier environments?
cirque, glacial trough, horn, arete, and moraine
What is a cirque?
A bowl shaped depression near the top of mountains and at the head of glacial valleys.
What is a glacial trough?
A U-shaped valley created by glacial erosion
What is a horn?
A pyramid-shaped mountain peak created by erosion of multiple glaciers
What is an arete?
A knife-like ridge usually radiating away from a horn that is formed by the erosion of adjacent cirques or glacial troughs
What is a moraine?
A ridge of sediment accumulated by a glacier.
What are the three types of moraines?
End moraines, lateral moraines, and medial moraines
What is an end moraine?
A moraine that forms across the front of the glacier and is perpendicular to glacier flow
What is a lateral moraine?
moraines that form along sides of the glacier down from the equilibrium line
What is a medial moraine?
A moraine that forms within the ice and are parallel to flow
What are the land features of continental glacial environments?
Moraines, drumlins, eskers, kames, and kettles
All continental moraines are ____ moraines
end
continental moraines have broad, high bands of ________
hummochy topography
What is a drumlin?
streamlined hill formed beneath a glacier oriented parallel to ice flow
What is an esker?
Sinuous ridge or series of ridges of sediment, formed beneath a glacier. Result of topographic inversion in meltwater tunnels
What is a Kame?
Irregular to conic shaped hill formed by topographic inversion
What is a kettle?
An irregular circular depression from topographic inversion. Melting of an ice block
