Geology Test 4
If a stream channel is 5 meters wide and 3 meters deep, and the velocity of the water moving through the channel is 10 meters/second, what is the stream's discharge (include units)?
150 cubic meters/sec
What percent of the total fresh water on the Earth is estimated to be contained in groundwater? ________%
30.1%
Most of the drainage in North Carolina will end up in the ______________________ Ocean.
Atlantic
Where would you find a trellis river pattern?
Pennsylvania and West Virginia
What does a profile of a river from its headwaters to its mouth typically show?
a curved shape that flattens out downstream
Which of the following rocks has the highest porosity?
a fine-grained shale
What is a spit?
a hook shaped sand bar that extends through the inlet
What is a badmouth bar?
a sand bar enclosing the inlets
Agree/Disagree- In a meandering stream, erosion (cutbank) occurs on the outside of the meanders, and deposition (point bars) occurs on the inside of the meanders.
agree
Which of the following would cause sea level to rise?
all of the choices
____________________________ develop when a steep, mountain stream in a narrow valley deposits its sediment on a large, much flatter plain.
alluvial fans
Which of the following most likely indicates a submergent coastline?
an irregular coastline with branching estuaries and embayments
An aquitard is a material that hinders groundwater flow. An _______________ is a material through which groundwater flows easily and is often a source for drinking water.
aquifer
What are pore spaces?
area between sediments
What is a drainage basin?
area of land including the river and elevation around it
Where would you find a rectangular river pattern?
at faults and joints, such as the ones on the west coast
A _________________________________ forms when a sandbar completely seals a bay off from the open ocean.
bay-mouth bar
What is it called when sediment washes at an angle?
beach drift
The process of ________________________ adds sand to beaches, but may not last long and is very expensive.
beach nourishment
Gravel in a stream generally moves as part of the ________________________ load.
bed
What is wave refraction?
bending of waves due to refraction as waves enter more shallow water depths
_________________ rivers are characterized by interwoven channels, multiple channel bars and a high sediment load, typically forming at the base of a mountain range.
braided
A wall built parallel to the beach within the open water to create a quiet harbor behind the wall is called a __________________.
breakwater
__________________ is the maximum amount of sediment that a river is capable of transporting.
capacity
What are some examples of impermeable sediment?
clay, silt, tightly cemented gravel
What is the recharge zone?
clouds and rain
What is the shape of a meandering river?
curves and winds
What are oscillation waves and how are they shaped?
deep water waves; more circular
What kind of river pattern do you find in North Carolina, specifically the neuse river?
dendrite pattern
What are caves made from?
dissolved away limestone (CaCO3)
The land area that contributes water to a stream system is called a _______________________.
drainage basin
What is Drawdown?
dropping of the water table
What is the formula for gradient?
elev. a - elev. b / distance
What is the formula for calculating the water table elevation?
elevation at the top of casing - depth of water
_____________________ coastlines occur when there is relative drop in sea level or uplift of land.
emergent
What is the hydrologic cycle?
evaporation, condensation, precipitation
Low-gradient rivers typically have well developed _____________.
floodplains
What is channelization?
forcing a river to flow in a particular path
If the elevation of the water table is above the elevation of a stream, such that there is an inflow of groundwater to the stream, it is called a ___________________ stream.
gaining
The steepness or slope of a stream channel is also called the __________________________.
gradient
What causes tides?
gravitational force
A wall built perpendicular to shore for the purpose of trapping sand is called a _______________.
groin
What kind of feature is associated with a radial river pattern?
high elevation
Which of the following materials probably has the highest permeability and would be the best aquifer?
highly fractured granite
What is an aquifer?
holds and transmits water
Where is the velocity fastest?
in the center of a straight river and the outside of a curvy river
In what direction does a spit typically grow with time?
in the same direction as a longshore current
If the cross-sectional area of the stream above changes to 30 meters2 and velocity remains the same, will the discharge increase or decrease? ______________
increases
The velocity of water flow ________________ downstream, with respect to a higher volume of water flow.
increases
If water doesn't evaporate you have _________________________.
infiltration and runoff
Most groundwater pumped in the United States is used for
irrigation
Walls built perpendicular to the beach in pairs at the entrances to inlets and extending slightly out into the ocean to keep the inlet open are called ___________________.
jetty
Sink holes, sinking streams, and solution valleys are typical geological features that develop in _______________ topography.
karst
What type of rock does karst topography typically form in?
limestone
Currents that move sediment roughly parallel to the shoreline are called ____________________.
longshore current
________________ rivers are characterized by meanders, point bars, cutbanks, and wide floodplains.
meandering
How much has sea level risen in the past?
more than 200 meters
What is an unconfined aquifer?
open to Earth's surface and to infiltration (dependent on rain/recharge)
Waves in deep water move water particles in a circular path and are called ____________________ waves.
oscillation
What is a confined aquifer?
overlain by less permeable materials
_____________________ lakes form when meanders are cut off from the main part of a stream and remain full of water.
oxbow
What is one feature commonly associated with meandering streams?
oxbow lakes
What is transpiration?
plants giving out oxygen
Groundwater is primarily found in _________________ and fractures.
pore spaces
What is the unsaturated zone?
pore spaces filled with air
What is the saturated zone?
pore spaces filled with water
The volume of pore space in geologic materials is called the ________________. The ______________ is a measure of how interconnected the pore spaces are and how easily groundwater can flow through the material.
porosity; permeability
What is porosity?
proportion of open space
How does urbanization (paving etc.) affect runoff and infiltration rates in a small previously forested drainage basin?
runoff increases; infiltration decreases
___________________ is a groundwater problem that can occur in when wells are pumped too close to the coast.
saltwater incursion
What are some examples of soft stabilization?
sand bags, plant vegetation, beach nourishment, and relocation
What are some examples of permeable sediment?
sand, gravel, limestone
The zone in which all open spaces are filled with water is called the ___________________________ zone.
saturated
The ultimate base level for most streams is ________________.
sea level/ocean
When sea arches collapse, they can leave behind a knob of rock called a ____________________.
sea stack
A wall built parallel to the beach, on the beach to prevent waves from eroding the shore areas behind it is called _________________.
seawall
What are translation waves?
shallow waves
When the sun and moon are aligned so their gravitational forces are added together, this effect causes _____________________________ tides.
spring
A ______________ are dripstone features found hanging from the roofs of caves.
stalactite
A _______________________ is a local rise in the level of the sea during a hurricane or other storm.
storm surge
The _______________________ zone contains turbulent water from breaking waves.
surf
What is permeability?
the ability of a solid to transmit water
Groundwater velocity (the rate of movement of groundwater) is most strongly influenced by which of the following factors?
the hydraulic gradient of the water table
Which of the following does NOT affect the potential hazards of a shoreline?
the source of beach sand
What is runoff?
water flowing on the surface
What is infiltration?
water seeping into the ground
Springs form when the ____________________________ intersects the surface of the Earth.
water table
The upper limit of the saturated zone is known as the __________.
water table
The vertical distance between a wave crest and trough is called the _________________________________.
wave height
As a wave enters shallow water the waves will begin to bend and flow parallel to the shore. The bending of a wave is called wave ________________________.
wave refraction
What is the water table?
where the saturated and unsaturated zones meet
What is the formula for discharge?
width x depth x velocity
What is the main issue with a sea wall?
you can only access the beach during low tide
