quiz 3 geo ch 8-10
What percentage of Earth's total freshwater supply is groundwater?
30.1 percent
Briefly describe a general drainage basin.
An area drained by a stream is called a drainage basin, which is bounded by an imaginary line called a divide. The divide can be clearly visible as a sharp ridge, or in subdued topography, may be difficult to determine.
How does an oxbow lake form?
An oxbow lake forms when the bend of a meandering river is isolated from the river when it is cut off from the main river channel. This isolated bend becomes the oxbow lake.
In what ways does a stream transport its load, and which part of the load moves most slowly?
As a dissolved load As a bed load, which is the slowest mode of particle transport in streams As a suspended load
In a river, what happens to the channel size and discharge downstream?
Both channel size and discharge increase.
How does groundwater create caverns?
Caverns are created when acidic groundwater dissolves and carries away limestone.
Why is soil considered an interface within the Earth system?
Changes in the climate in the atmosphere create changes in soil texture and composition. Water from the hydrosphere that is added to soil from various sources allows the soil to be able to sustain plant life, which returns the water to the geosphere when it expires.
What causes creep, and how can it be recognized?
Creep is caused by the repeated expansion and contraction of the regolith, which may be caused by repeated freezing and thawing or wetting and drying. Creep can be recognized by tilted trees, tilted fences, and displaced retaining walls.
What are crevasses, and where do they form?
Crevasses are cracks that form in the zone of fracture at the top of the glacier. They form when tension is created as a result of the glacier moving over irregular terrain.
How does the rate of rock weathering in dry climates compare with the rate in humid regions?
Dry climates have much lower rates of chemical weathering and mechanical weathering than humid climates
How have human activities affected the rate of soil erosion?
Humans have increased the rate of soil erosion by removing vegetation through activities such as farming, logging, and construction.
Why do V-shaped valleys often contain rapids or waterfalls?
In many V-shaped valleys, resistant bedrock upstream creates rapids by acting as a local base level, whereas downcutting occurs in less resistant bedrock downstream.
What is the major distinction between internal and external Earth processes?
Internal processes are driven by processes like plate tectonics, and external processes are driven by the Sun.
What are the components of glacial movement?
Plastic flow, which is an internal flow within the ice Basal slip, which is the process of the glacier sliding along the ground.
How do glaciers acquire their load of sediment?
Sediments and rocks are plucked off the ground surface at the base and sides of the glacier.
How do stalactites and stalagmites form? Choose two correct processes.
[ not Stalactites form on the ceiling when water seeps through the ceiling and deposits calcite. Eventually a soda straw develops, which develops into a stalactite after many more depositions of calcite. Stalagmites form when calcite-rich water falls to the floor from the ceiling, splattering minute amounts of calcite on the floor. Eventually, a soda straw forms, and after many more such depositions, a stalagmite begins to take shape.]
Bed load of a stream is carried ________.
[not in suspension]
________ is the total quantity of sediment carried by a river.
[not load maybe capacity]
What are the effects of Ice Age glaciers besides the formation of major erosional and depositional features?
[not pluvial lakes sea-level changes changes to rivers and valleys creation of proglacial lakes]
The water table is ________.
a boundary between saturated rock below and unsaturated rock above
A natural levee is ________.
a depositional feature
A cirque represents an erosional feature formed ________.
at the head of a glacier
Valley or alpine glaciers are normally found in ________.
former stream beds
Which of the following is not a significant factor in determining whether precipitation will soak into the ground or run off on the surfaces?
lithology
One important relationship between chemical and mechanical weathering is ________.
mechanical weathering can produce smaller pieces of rock that have more surface area for chemical weathering to work on
At a bend in a river, the main erosion is ________.
on the outside of the bend
The greater the channel roughness, the ________ the stream.
slower flowing
Frost wedging is the major weathering process contributing to the formation of which regolith material?
talus slopes
As stream discharge increases ________.
velocity, width, and depth increase
What is the most important erosional agent in deserts?
water