Exam 3
What is a mud flow?
Downward flow of fine particles (mud) and large amounts of water
How are the sediments deposited by mass wasting events generally described?
Due to rapid, often violent deposition, mass movement sediments tend to be angular and unsorted.
Why is sediment yield an important consideration in a discussion of water supplies?
Sediment is a common water pollutant.
Why are landslides more common on steep slopes?
Slope angle determines the relative magnitude of driving forces.
How do slumps and translational slides differ?
Slumps are rotational translational slides are planar
What is the most dangerous hazard associated with hurricanes?
Storm surge
What is the main drawback of seawalls?
They reflect wave energy back across the beach and cause erosion.
What adverse effect do groins and jetties both have on coastal erosion?
They stop longshore transport of sand and starve down-drift areas of sand.
Warning systems for landslide-prone areas include:
Time for evacuation, stop or reroute traffic
Erosion of the base of a slope may increase landslide hazards by oversteepening the slope.
True
Grading of slopes can either increase or decrease landslide hazards.
True
Wastewater renovation relies on what processes to purify water?
natural purification in the soil
Saltwater intrusion results from
overpumping of groundwater
Road-building and other construction process do what to the slopes that may trigger landslides?
oversteepen slope.
Common pollutants in water include (select more than one correct answer):
pathogenic microbes oxygen-demanding waste petroleum toxic waste nutrients sediment
What is the principal cause of septic system failure?
poor soil drainage
Define groundwater.
precipitation that has infiltrated through the soil into the rocks and sediment below
A(n) ________ is a narrow, potentially dangerous, flow of water away from the beach and into deep water.
rip current
________ are caused by the collapse of caverns.
sinkhole
List two criteria that are used to classify mass movements?
slow and rapid
How do slumps and translational slides differ? Select more than one correct answer.
slumps are rotational translational slides are planar
A(n) ________ is a lethal rise in the sea surface level caused by a hurricane.
storm surge
How much has the state of Kentucky spent on acquisition of landslide-prone homes from 2005-2007?
$617,000
Hurricanes develop from areas of low atmospheric pressure called tropical ________.
Depressions
What is a sinkhole?
Depressions that form when a portion of the lithosphere below is eroded away.
Coastal erosion along the Gulf coast has accelerated by 30-40% over the past 100 years and is due to:select more than one correct answer
1. coastal engineered structures 2. gradual rise of sea lever due to climate change 3. land subsidence due to groundwater and petroleum extraction
Causes of subsurface ground failure include: select more than one correct answer
1. subsidence caused by withdrawal of groundwater 2. dissolution of limestone 3. subsurface coal mining 4. subsidence caused by withdrawal of oil and gas 5. dissolution of salt beds
The incidences of coastal hazards is expected to increase in the future because (select more than one correct answer)
1. warming climate causing stronger hurricanes 2. warming climate causing stronger rip currents 3. increasing population and development in coastal regions
At which wind speed does a storm become a hurricane?
74 mph
At which temperature does ocean water need to be for hurricane formation?
82 degrees
________ is a "soft" solution to coastal erosion that tends to imitate natural processes.
Beach nourishment
What are the 3 biogeochemical cycles that humans have altered?
Carbon Cycle Nitrogen and Phosphorus Cycles Cyanide Process
What are two naturally occurring chemicals that are toxic?
Cyanide Mercury Carbon Nitrogen and Phosphorus Sulfur dioxide and Nitrogen dioxide
What is the class of synthetic chemical discussed in the video?
Endocrine Disruptors (EDC)
A cone of depression forms when water is pumped from an unconfined aquifer, but not when water is pumped from a confined aquifer.
False
Heavy metals remain suspended in the water column indefinitely.
False
Hillslopes typically are static systems.
False
Landslides pose a problem in the Texas Gulf Coast.
False
Runoff in areas of shale bedrock tends to be less that in areas of gravel because of the high porosity of shale.
False
Slumps and debris flows tend to occur separately in time and space.
False
Soft stabilization of coastal erosion utilizes seawalls constructed of soft, cushioned materials versus hard materials such as steel.
False
The water table separates confined and unconfined aquifers.
False
What is soil creep?
Gradual or downhill movement of soil. (Slowest)
What is the driving force behind landslides, slips, debris flows, slumps?
Gravity
What is the name given to the topography associated with the dissolution of soluble rock?
Karst
________ and _______ can severely increase landslide hazards in mountainous terrains.
Logging road construction
A comprehensive term for any type of downslope movement of Earth materials is
Mass wasting
What is the term for the movement of the ground surface as a result of readjustment of the overburden due to collapse or failure of underground mine workings?
Mine subsidence
Define porosity.
Percentage of earth material that consists of void spaces.
__________ is a kind of catch-all term for any substance that's in the wrong placeor in the wrong concentrations in the environment.
Pollution
What is a debris flow/landside?
Rapid downward flow of debris.
What is a rock fall?
Rapid falling pieces of rock from a cliff or steep slope. (Fastest)
________ are designed to provide mechanical support at the base of a slope.
Retaining walls
What is the pile of rubble at the base of a cliff called?
Talus
Why does withdrawal of fluids sometimes lead to subsidence?
The fluid pressure provides partial support for the overlying rock mass.
How does road construction associated with timber harvesting contribute to landslide hazards?
The roads alter the movement of surface water and groundwater.
What contributes to seacliff erosion at high rates? Select more than one correct answer.
The seacliff may be exposed to terrestrial mass wasting processes. The seacliff may be exposed to wave action
Why does river damming sometimes contribute to coastal erosion?
The supply of sediment to beaches is shut off.
Why might the infiltration of water deep into a slide mass increase landslide hazards?
The water increases the pore water pressure, effectively lifting the slide mass from stable ground beneath.
Why are sea walls constructed?
They are constructed to protect coastlines against wave attacks by absorbing energy. They are concrete structures built parallel to the coast.
Hurricanes tend to strengthen over warm ocean water.
True
Sinkholes often result from water table fluctuations.
True
The goal of groin installation is to trap sand.
True
The velocity of surface water flow influences the amount of soil or sediment the water can erode.
True
Thermal pollution is harmful to some organisms, but actually helps others survive.
True
Tropical cyclones are called ________ in the western Pacific Ocean.
Typhoons
The ________ disaster in Italy was caused by landslides entering the lake
Vaiont Dam
Why do waves expend so much energy on a rocky headland?
Waves refract toward the headland on both sides.
What is mass wasting?
Whenever gravity pulls sediments downhill.
Vegetation influences landslides in part by
anchoring the slope materials
The balance of sediment input and output along a stretch of coastline is called the ________.
beach budget
Why are the impacts of coastal hazards so great?
because many populated areas are located near the coasts
The level of decaying organic matter in water is indicated by what measure?
biochemical oxygen demand
Define permeability.
capacity of water to flow through earth materials
Which of the following would likely serve as an aquitard (slows or hinders the movement of water)?
clay
Slope processes are dynamic features that depend on which of the following? Select more than one correct answer.
climate vegetation water rock types geologic time topography
The following human land-use changes can impact the occurrence of mass wasting events: select more than one correct answer
dam construction backfilling with loose materials urbanization irrigation inadequate controls of storm water runoff
The Colorado River Basin: Which of the following issues are found in this area? Select more than one correct answer.
dam construction has reduced flow in the river dam construction has impacted sediment distribution water from the river is appropriated to seven western states and Mexico the river is essentially dry by the time it reaches the Gulf of California
The boundary between drainage basins is called the
drainage divide
The noncohesive downslope movement of saturated Earth materials is called a(n) ________.
earthflow
What is the principal cause of cultural eutrophication?
elevated levels of phosphorus and nitrogen
What aspect of hurricanes tends to cause the greatest death and destruction?
flooding from rain, waves, and storm surge
In Yosemite National Park, strong bedrock influences the formation of what types of hillslopes?
free cliff faces and talus piles
On what information is a landslide hazard map based?
geology and inventory of past landslides
Engineered structures are designed to protect man-made structures along the coast. These include: select more than one of the following
groins jetties seawalls
What ranges of porosity and permeability make good aquifers, as in high or low?
high porosity and high permeability
Serious coastal hazards include: select more than one correct answer
hurricanes tsunamis rip currents
In the permeability demonstration, how was the permeability of the clay described?
impermeable
Vegetation decreases runoff by
intercepting rainfall and slowing its fall to the ground
If sediment is from natural sources, why is it considered a water pollutant?
it is an out-of-place resource
Why is drainage control sometimes an effective method of landslide control?
it reduces the amount of water in the hillslope materials
Why is municipal wastewater sludge considered problematic?
it sometimes contains heavy metals
A pair of ________ typically protects the channel of a river entering the sea.
jetties
The current flowing parallel to and just offshore of a beach is called
longshore current
Hurricanes in the tropical Atlantic Ocean tend to originate as
major pressure lows over the equatorial ocean.
All slope movements fall under the term ________.
mass wasting
What is the principal goal of beach nourishment?
to maintain a positive beach budget and alleviate the need for engineered structures
What is the circular pattern of winds called?
tropical depression
Coastal landscapes are capable of rapid change because continental and oceanic processes converge there.
true
As waves enter shallow water, what happens to them? Select more than one correct answer.
wavelength decreases wave height increases.
What 3 measurements are obtained to tell us about the intensity of a hurricane?
wind speed, temperature, air pressure
Which of the following does not influence wave size?
wind temperature
