8.5-8.7 and 8.8-8.9 Notes Flashcards
the lifting or removing of loose particles such as clay and silt (small particles)
deflation
wind blown sand blasts exposed rock, smoothing and polishing them
Abrasion
Where is wind erosion more effective?
Deserts than humid regions
Wind can only pick up what size particles?
Small light particles
in deserts the arid sediments are?
lighter
in humid regions the sediments are
wet and heavier
as energy is lost, larger particles are dropped first then smaller materials
graded bedding
how does wind deposit sediment
graded bedding
deposition due to wind results in
small sorted particles (large on the bottom, smaller as you go up)
wind blown silt blankets in a region
layers of loess
sand accumulated in a mound
sand begins to accumulate wherever an obstruction crosses it’s path slows movement
sand dunes
gentle slope is on the
windward side
steep is on the
leeward side
sloping layers caused by sand being deposited on the sheltered side of a dune. These layers are inclined in the direction the wind is blowing
crossbeds
erosion of sediments by wind is most common in what climates and where
arid climates along shorelines
wind deposits consist of
fine grained well sorted particles
wind deposited sediments have a what appearance and what layers
frosted appearance and cross bedded layers
what moves sand dunes
wind
what can winds cause
sand-blasted bedrock
where the land and a body of water meet
shoreline
waves along the shoreline are constantly ______, ______, and ______ sediments
weathering, eroding, depositing
balance between erosion and deposition
coast lines
waves can throw thousands of tons of water against the shore causing cracks in the coastal structures
Wave Impact
waves hit the shore at a slight angle because of this refraction headlands (or land that sticks out into the ocean) receive more erosion and the bays (areas between headlands) receive more deposition
Wave Refraction
the grinding of rock fragment by the waves cause smooth rounded stones, pebbles, and shells to land on the shore
Abrasion
the longshore current shore flows parallel to the shore and moves large amounts of sediments horizontally along the coastline
longshore transport
shoreline features that are caused by the removal of sediment
erosional features
sediments moving along the shore are deposited in areas where the water slows
Depositional features
permanent land formation that forms between the mainland and the ocean
barrier beach
a temporary pile of sand at or above sea level
sand bar
deposition due to waves is usually ____ and _____
sorted and rounded
wave action rounds sediments as a result of
abrasion
wave action causes changes in shoreline features including
beaches, sandbars, and barrier islands
waves approaching a shoreline move sand _____ to the shore within the zone of breaking waves
parallel
longshore dirt moves sand along the beach in the direction of the
ocean current
mass movement (particles)
unsorted angular rock fragments
wind (particles)
small sorted particles
waves (particles)
sorted and rounded
thick masses of ice that form over thousands of years
Glaciers
ice that flows down mountain valleys at high altitudes
valley glacier ex. Alaska
ice that covers a large region where the climate where the climate is extremely cold, icebergs and ice ages
ice sheet ex. Antarctica
frost action loosens blocks of rocks and the glacier then lifts them away
plucking
the ice slides over the rocks like sandpaper
Abrasion
scratches left on the bedrock as the glacier moves over it
striations
deposition due to glaciers results in
unsorted and angular sediments
ice carves a wide valley pushing everything in it’s way
u-shaped valley
unsorted sediments left behind from a glacier
till
ridges of till
moraine
an oval shaped mound of till
drumlin
a lake formed when the glacier begins to melt
glacial lake
small lake formed when a chunk of ice becomes dislodged and then melts
kettle lake
larges boulders dropped by melting ice
glacial erratic
glacier sediments are
unsorted
glaciers form what valleys
u-shaped
glaciers leave behind
parallel scratches (striations)
glaciers leave behind grooves in bedrock and parallel scratches (striations) from what
abrasion
glacial features include
moraines, drumlins, kettle lakes, finger lakes, and outwash plains
a block of ice left by a glacier will create
a kettle lake
a teardrop shaped piles of sediments left by a glacier is called a
drumlin
the movement of water in streams, rivers, and other channels
stream flow
the course that the water flows
stream channel
friction caused by
shape, size, and roughness of the channel
less friction
faster
more friction
slower
the slope or steepness of a stream channel
gradient
the volume of water that flows past a certain point in a given time
stream discharge
variables that affect discharge
size of channel, velocity, climate
a bend in a stream
meander
streams ____ in gradient as it moves from it’s source to it’s mouth
decrease
streams start
at higher elevations and move downhill
upstream the
channels are smaller, rougher, and have more friction (slower)
downstream has a higher
amount of water flowing through it (discharge)
downstream has
channels that are wider, smoother, and have less friction (faster)
downstream has
channels that are wider, smoother, and have less friction (faster)
smaller streams that flow into larger streams
tributaries
a primary agent of erosion
running water
the speed of the stream depends on the ___ and _____
gradient (how steep the slope) and volume (discharge)
sediments transported by streams tend to become
rounded as a result of abrasion by bumping into other rocks
the size of the particle transported depends on the
stream’s velocity
which particles settle first in water
heavy, dense, and round
which particles slide and bounce along the bottom
sand and pebbles
which particles are carried in suspension
silt and clay
what is carried in a solution
minerals
as the velocity increases the size of the sediment a particle can carry
increases
as the amount of water in a stream increases (discharge) the velocity will
increase
what is the area drained by a stream and it’s tributaries
watershed
when a stream ends at a body of water the largest sediments are dropped first as the water ___
slows down
which sediments go the farthest
the smallest
what is sorting of sediments by a stream called
delta
streams generally erode their channel by
lifting loose particles
the stronger the current the more
erosional power it has
sediments carried in a stream can erode solid rock by the process of
abrasion
streams transport sediments by
solution, suspension, and bed load
solution
dissolved materials
floating materials travel as fast as the water (most common)
suspension
large sediments that are transported by rolling or scooting
bed load
the maximum load a stream can carry
capacity
occurs as a stream flow decreases
stream deposition
larger particles drop
first
smaller particles drop
last
stream _____ varies within a stream channel
velocity
maximum velocity occurs on the _____ of channel bends
outside
minimum velocity occurs on the ____ of bends
inside
highest speed in center
straight section
steeper on the left (erosion)
gentle on the right (deposition)
faster in the center of the deepest location
left meander
steeper on the right (erosion) gentle on the right (deposition)
faster in the center of the deepest location
right meander
a wide valley created when a river erodes the banks of it’s stream channel. the side to side cutting creates a flat valley floor
floodplain
where deposition cuts off meanders this is formed
oxbow lake
forms when sediment builds up at the mouth of a river because the water slows as it enters a larger body of water
delta
streams form what shaped valleys
v-shaped
stream deposits are
sorted round and smooth
the velocity of a stream is greatest on the ___ of a meander
outside
what occurs on the inside of a meander
depostion
is the velocity fast or slow on the inside of a meander
slow
what occurs on the outside of a meander
erosion
is velocity fast or slow on the outside of a meander
fast
