Unit 5 Flashcards
erosion
a process by which the products of weathering are transported by a natural agent, such as wind, water, ice, or gravity
weathering
a natural process by which atmospheric and environmental agents such as wind, rain, and temp changes disintegrate and decompose rocks.
The primary difference between weathering and erosion
is that weathering occurs in place whereas erosion involves movement to a new location
Once weathering has broken particles away, erosion can occur. Erosion is the process of actually moving the broken sediment, soil or rock particles.
Compare the gradient and volume of water carried in stream flow between rivers that are newly formed, mature, and old age
new mature old
gradient: high/ lower/flatter lowest,very flat
steeper
Volume
of water: low high highest
what is the effect on size and shape of transporting sediment?
More rounded and aerodynamic shapes of smaller sizes require less velocity to be transported/moved
How does the shape of particles change as they are transported farther from their origin?
As particles are transported farther they become smaller and have more surface area exposed and sometimes more rounded
Where are angular and rounded sediments usually found
rounded sediments are usually found in rivers/ water after being transported by a river
angular sediments are usually located near cliffs or places where the rock could fall from a hight
Compare the water required to fill pore spaces, the time required for draining, and the water remaining around sentiments for rounded particles that are 3 mm and to those that are 8 mm round (given equal volumes)
- same amount of water required to fill pore spaces
- larger beads would require less time for draining
- and there would be less water remaining round larger bead
explain the formation of a sand dune
A barrier keeps sand in its relative place. the wind pushes sand around a barrier in the direction the wind is blowing. As the wind deposit more sand the wind barrier grows larger allowing for more sand build up on both sides of the barrier until the original barrier is covered
Explain sediment distribution and deposition as a river empties into a still body of water
as water velocity slows a fan-shaped delta will form with larger sediments (like boulders) closer to the mouth of the stream and finer sediment as you move outward to the end of the delta. The finest sediments, like clay may float to the surface and carried away
What factors affect the amount of sediment transported by stream
water velocity, shape of stream channel, stream gradient
If water storage is on its maximum and toldtal percipitation excedes vapotranspertation what wil hapen ?
flooding
Which agent of a Rosian transport sediments that forms moraines
glaciers
what is the primary agent of erosion in a desert
wind
what are striations? how do they form?
long parallel grooves in bedrock left behind. When rocks get stuck to the base of a glacier and the glacier drags it across the bedrock as it moves causing abbrasion
what do striations show
the direction of glacier movment
what is forost action/ ice wedging
when water seeps into cracks of a rock and then freezes, its volume then increases by 10% and creates preasure on the surrounding rock. Every time the water freezes the crack becme wider untill it is eventually wedged apart
what climate has the fastest rate of weathering on a rock?
hot wet climates
what factors determine why some rocks weather more rapidly than other rocks?
rock composition, amount of time rock is exposed to weathering, amount of surface area availabe for weathering, climate, topography+elivation, human plant and animal activities
what are the most important facctors affecting the water budget
amount of precipitation vegitation amount of water usage wind temp
what is the most important facctor in determining what type of soil will form?
parent rock, the rock from which the soil was wethered
how do caverns form
A cavern is formed by chemical weathering. As ground water flows through cracks of rocks rich in calcite carbonic acid slowly dissolves and enlargens the cracks everntually creatinga cavern
how do sinkholes form
when rock dissolves or sediment is removed from under a surface causing a depresion. or when caves or mining cites collapse
what is abbrasion
The collision of rocks that result in the breaking and weathering away of rocks from mechanical
pros and cons of dams
pros: prevent and control flooding, can provide hydroelectric eneergy
cons: can cause sediment builup (which can cause pollution, interfears with wildlife and can stop the natural migration of many speacies of fish
What is the potential effect of climate change on the hydrology of a river system
as climate changes evapotranspirisim can exceed precipitation causing a river system to lose water volume, therefore velocity dereases, and therefore there is less erosion
what are some clues used to determine glacier movment
striations, drumlins
what is albedo as it relates to ground surfaces
Reflective property of glacier ice. It is extremely powerful and can cause one to go blind. Ice with this property is also much harder to melt because the light bounces off
How can glacial movment be used to explin the orientation of the finger lakes
As glaciers advance they draged large pieces of rock with them that cause abrasion and carve out the fingerlakes. as the glaciers then receeded they dropped a terminal moraine which stoped the river from flowing, creating a lake
drumlins
long low tear shaoed mounds of tikk. the aces of the drumlins run parallele to the direction of glacier movment
