|
Which of the following are common tectonic settings associated with volcanic activity? A.mantle plumes |
A.mantle plumes B.continental rifts C.island arcs D.continental arcs |
|
Which of the following is a present-day example of a continental rift? A.the South American rift valley |
C.the East African rift valley |
|
Which of the following often forms after continental rifting? A.a new mountain |
B.a new ocean basin |
|
Where are continental volcanic arcs found? A.on the downgoing plate near a mid-ocean ridge |
B.on the overriding plate near a subduction zone |
|
How are continental rift magmas and continental arc magmas different? A.Continental arc magmas are more dangerous than continental rift magmas. |
C.Continental arc magmas are more viscous than continental rift magmas. |
|
How are island arc and continental arc magmas similar? A.Both are formed near transform boundaries. |
C.Both are formed near subduction zones. |
|
Which of the following are examples of modern-day island arcs? A.Mariana Islands |
A.Mariana Islands B.Aleutian Islands |
|
What is a mantle plume? A.a circular column of rock that rises from close to Earth’s surface |
D.a circular column of magma that rises from deep within Earth |
|
Which of the following is an example of modern-day mantle plume volcanism? A.East African rift |
B.Hawaiian Islands |
|
The production of magma (magmatism) at divergent boundaries is characterized by which of the following? A.Outpourings of lava/magma originating mostly from the continental crust. |
B.Melting caused by decompression D.Outpourings of lava/magma originating from the mantle. |
|
At what tectonic setting is Hawaii located? A.oceanic hot spot |
A.oceanic hot spot |
|
What drives melting at divergent boundaries? A.a localized plume of magma rising to the surface |
C.decompression melting |
|
Which of the following tectonic settings does NOT produce volcanism? A.divergent continental-continental boundary |
E.transform boundary |
|
A ___________ has broad and moderately steep flanks and a steep summit. It results from the eruption of a mixture of both lava flows and pyroclastic deposits that contain less fluid materials and travel shorter distances. |
composite volcano |
|
A wide volcano that produces mainly basaltic lava flows is called a _________ |
shield volcano |
|
A very steep-sided volcano built primarily from ejected lava fragments is called a _________ |
cinder cone |
|
Broad sheets of fluid _________ lava travel long distances and give shield volcanoes their distinctive shape. |
basaltic |
|
Moderately viscous and gas-rich ________ lavas can erupt as lava flows or pyroclastic materials, leading to the steepening slope of composite volcanoes. |
andesitic |
|
Explosive eruptions of _____________ create steep-sided cinder cone volcanoes. |
pyroclastic materials |
|
Describe a Cinder cone vocano: |
-Volcano known for reddish-brown lapilli -Volcano with a crater at the summit and steep flanks -Cinder cones are formed by the ejection of mostly pyroclastic fragments that range from the size of fine ash to a bomb, and also lava. Since these volcanoes usually result from a lone eruption and are short-lived, they are distinctively high angled and small in size. |
|
Describe a Shield volcano |
-Volcano with very broad slopes and a caldera -Volcano known for long lava flows and lava tubes -Shield volcanoes are broad, slightly domed structures that resemble a warrior’s shield, produced by the accumulation of fluid basaltic lava. |
|
Describe a Composite cone volcano |
-Volcano known for erupting lava and pyroclastic material -Volcano with a steep summit and broad, moderately steep flanks -Composite volcanoes are the most scenic, yet potentially dangerous, volcanoes. They are large, symmetrical structures. These volcanoes owe their large structures to the eruption of fluid basaltic lava and their height to the silica-rich magmas that travel less than a few kilometers, and some pyroclastic materials. |
|
What is the difference between the different types of volcanos? |
Each volcano type reflects the composition of the lava, meaning geologists can make inferences of the type of lava simply by examining the form of a volcano. Cinder cones are known for their reddish-brown lapilli, steep sides, and crater at the peak. Shield volcanoes are known for having long lava flows and lava tubes, and for having broad slopes and a caldera. Composite cones are known for erupting lava and pyroclastic material, and for having a steep summit and moderately broad flanks. |
|
What kind of volcano is the Mauna loa in Hawaii? |
A shield volcano |
|
Give examples of composite cone volcanos: |
-Cotopaxi, Ecuador -Fujiyama, Japan -Mt. Saint Helens, Washington |
|
Give examples of cinder cone volcanos: |
-Paricutin, Mexico -San Fransisco Peaks, Arizona |
|
How are cone shaped volcanos formed? |
Volcanic activities usually begin when a crack develops in the crust as magma moves forcefully toward the surface. The upward movement of the gas-rich magma is confined within a circular conduit, which terminates at a surface opening. Subsequent eruption of lava, pyroclastic material, or both occurring within long periods results in the formation of a cone-shaped structure called a volcano |
|
Why are shield volcanoes wider than composite volcanoes? A.The lava that flows out of shield volcanoes is less fluid than the lava that flows out of composite volcanoes. |
C.The lava that flows out of shield volcanoes is more fluid than the lava that flows out of composite volcanoes. |
|
Which of the following are types of volcanoes? A.Caldera |
C.Shield volcano D.Cinder cone E.Composite volcano |
|
What information do geologists use to classify volcanoes? A.Height of peak and type of deposits |
C.Shape and type of deposits |
|
Cinder cones are made of________. A.pyrobasalt deposits |
C.pyroclastic deposits |
|
In general, how often do most cinder cones erupt? A.Most cinder cones erupt once. |
A.Most cinder cones erupt once. |
|
What are shield volcanoes generally made of? A.Basalt flows |
A.Basalt flows |
|
What is the range of shield volcano height? A.300 to 10,000 meters |
A.300 to 10,000 meters |
|
What are composite volcanoes made of? A.Pyrobasalt deposits |
B.Pyroclastic deposits C.Basalt flows |
|
Why are shield volcanoes wider than composite volcanoes? A.The pyroclastic material that comes out of shield volcanoes is less fluid than the lava that flows out of composite volcanoes. |
D.The lava that flows out of shield volcanoes is more fluid than the lava that flows out of composite volcanoes. |
|
What type of magma erupts out of dome complexes? A.Felsic magma |
A.Felsic magma |
|
What type of volcanoes are the highest? A.Composite volcanoes |
B.Shield volcanoes |
|
What is the range of dome complex height? A.20 to 5,000 meters |
D.500 to 2,000 meters |
|
When do Ice-Jam flood occur? |
Ice-jam floods occur when ice obstructs the flow of water across a channel, effectively damming the stream. As a consequence, the stream’s water level rises and overflows its banks. The ice jam will eventually break, which may generate an additional destructive surge of water. |
|
When do Dam-Failure flood occur? |
Dam-failure floods occur when a human-made dam or levee breaks. These floods are particularly catastrophic because they can rapidly submerge an area without warning. |
|
How are regional flood and flash flood similar? |
1)Both regional and flash floods result from the release of large quantities of precipitation and/or snow melt. |
|
How are regional and flash floods different? |
1)Regional floods occur over broad areas and may persist for a long time, whereas flash floods are local and brief. 2)Flash floods are more intense than regional floods because they occur in regions where surface water accumulates more rapidly. 3)A region’s surface conditions and topography determines whether it will be susceptible to regional or flash flooding. Flat regions favor regional floods because the gradual slope of the landscape slowly directs water into a stream channel, whereas hilly or mountainous regions favor flash floods because steep slopes that can quickly funnel water into a stream channel are present. 4)Ground that is impermeable to water (i.e., asphalt, concrete, and nonporous rock) favors flash floods because it allows surface water to rise rapidly, and ground that is made of porous, unconsolidated sediments (i.e., some soils) favors regional floods. 5)The high intensity of flash floods makes them deadlier than regional floods |
|
What strategies to governments typically rely on to reduce flood damage? |
Governments typically utilize four different strategies to reduce flood damage: artificial levees, dams, channelization, and zoning regulations. |
|
What are artificial levees? |
Artificial levees are mounds of earth (or sometimes concrete walls) that increase the height of a stream’s banks. They prevent flooding by increasing the volume of water that a channel can hold. -A(n) artificial levee confines water flow and can experience significant erosion. Constant maintenance is required. |
|
What are dams? |
Dams retain water in a human-made reservoir by obstructing water flow. Water is allowed to pass through the dam in a controlled manner, thereby preventing flooding. Sometimes the water flow through a dam is used to turn turbines that generate electricity. -Besides flood control, a(n) dam can also be used to generate hydroelectric power. However, they are expensive to build and maintain. |
|
Describe channelization |
Channelization involves modification of the stream channel to improve stream flow. It usually entails widening or straightening a stream channel so the channel can hold more water without flooding. -Removing obstructions from a river channel is a form of a(n) channelization. It can make a river more navigable, but may also increase bank erosion due to increased water flow. |
|
How do zoning regulations work to reduce flood damage? |
Zoning regulations attempt to minimize the damages resulting from flooding by inhibiting construction in areas that are prone to flooding. -Zoning regulation is/ are cheap to implement, but it/they can adversely affect property values. |
|
What can produce a flood? |
Storms that produce heavy rains, such as large thunderstorms, are a major cause of floods. When rain falls into a drainage area, it eventually becomes part of rivers and streams. |
|
What is discharge? |
the volume of water passing through a river over a given time |
|
What is peak flow? |
If the highest amount of river discharge, called peak flow, overtops the banks of the river, flooding will occur. |
|
What is a floodplain? A.a flat surface next to a river channel |
A.a flat surface next to a river channel |
|
What is a natural levee? A.a ridge of flood deposits next to a river channel |
A.a ridge of flood deposits next to a river channel |
|
How does the formation of a natural levee impact flooding? A.Natural levees raise the height of the stream channel, reducing the amount of flooding that will occur on the floodplain. |
A.Natural levees raise the height of the stream channel, reducing the amount of flooding that will occur on the floodplain. |
|
Which of the following are classifications describing how rock and other material move downslope? A.creep, flow, slip, waste, fall |
D.fall, slide, slump, creep, flow |
|
What is mass movement? A.movement of material under the influence of gravity alone |
A.movement of material under the influence of gravity alone |
|
How is a fall different from creep? A.Falls occur slowly and in areas with high slope, whereas creep occurs rapidly in areas with low slope. |
C.Falls occur rapidly and in areas with high slope, whereas creep occurs slowly in areas with low slope. |
|
How are slumps and slides related? A.Slides are a type of slump in the special case where the rupture surface is linear. |
D.Slumps are a type of slide in the special case where the rupture surface is curved. |
|
What would likely happen to a fence on a hill over time if the fence were built perpendicular to the hill’s slope? A.The top of the fence would likely bend downhill as creeping rocks moved under the fence and pushed the fence bottom upslope. |
D.The top of the fence would likely bend uphill as creeping rocks moved under the fence and pushed the fence bottom downslope. |
|
How are debris avalanches and flows related? A.Debris avalanches are small, slow flows of rock. |
C.Debris avalanches are large, rapid flows of rock. |
|
Which type of mass movement event requires the addition of water? A.slump |
B.flow |
|
Of the following types of mass wasting, which tends to be the fastest moving and most destructive? A.solifluction |
B.rockslides |
|
Which of the following examples of mass wasting is characterized by a crescent-shaped scarp or cliff at its head? A.earthflow |
D.slump |
|
Which of the following types of mass wasting is extremely slow and occurs when saturated soil flows downslope? A.debris flows |
D.solifluction |
|
At a local landfill, the liner beneath the trash was being repaired. In the process, trash from the base of the slope was removed and piled on top of the landfill. After an unusually heavy rainfall, the slope failed very quickly along a curved surface. Which of the following types of mass wasting best describes this slope failure? A.slump |
A.slump |
|
During the eruption of Mount St. Helens on May 18, 1980, snow and glacial ice on the mountain melted and rushed down the Toutle River. What is the name given to this specific type of mass wasting? A.rockslide |
D.lahar |
|
When considering mass wasting, which of the following factors is most influential in the downslope movement of weathered particles? A.removal of vegetation |
C.gravity |
|
Which of the following responses are examples of how water can promote mass wasting? A.Water enhances the ability of vegetation to grow on weathered particles, promoting mass wasting. |
B.Water can saturate sediment, reducing the integrity of the slope and allowing it to move. C.When water is added to weathered particles, the mass of the sediment is increased, which can cause slope instability. E.Waves and streams can undercut banks and cliffs, causing them to fail. |
|
When dry sediment accumulates, the angle of repose represents what property of the deposit? A.The angle of repose is the angle at which sediment accumulates when slopes move very slowly. |
B.The steepest angle at which those sediments can accumulate and remain stable. |
|
When sediment accumulates, the angle of repose can be increased by changing which of the following conditions? A.undercutting by waves and streams |
C.slight addition of water to the sediment |
|
How many different types of mass movements are there and what are their names? |
There are five main types of mass movements and each has different characteristics. The material within a particular mass movement may be consolidated (like solid rock) or unconsolidated (like sand and mud). It may move downhill quickly or very gradually. It may rotate as it moves downhill or head straight down. -Slump, Flow, Fall, Creep, Slide |
|
What is a slump? |
Slump: involves a downward sliding of a mass of rock or unconsolidated material moving as a unit along a curved surface—creating a crescent shape at the head. -Mass movements that move blocks of materials and unconsolidated materials down a curved surface creating scarps on a slope are known as slump. |
|
What is a Flow? |
Flow: occurs when material moves downslope as a viscous fluid. -When unconsolidated material moves downslope as a viscous fluid it is called a flow. |
|
What is a Fall? |
Fall: a fall occurs when the movement involves the free fall of detached individual pieces of any size. This occurs on very steep slopes. -When large rocks become dislodged and drop down a steep slope, the mass movement is called a fall. |
|
What is a Creep? |
Creep: it involves the gradual downhill movement of soil or rock pieces. The major factor that facilitates this process is alternate expansion and contraction by freeze and thaw. -Creeps are very gradual mass movements in which the whole slope moves downhill slowly. |
|
What is a Slide? |
Slide: refers to mass movements in which there is a distinct zone of weakness separating the slide material from the more stable underlying material. Movement does not occur on a curved surface. It involves one piece of block. -A mass movement in which a cohesive block of earth or rock slips downhill relatively quickly in one piece along a zone of weakness is called a slide. |
|
What processes are mass movements influenced by? |
Mass wasting is influenced by many processes associated with all four spheres of the Earth system (i.e., atmosphere, hydrosphere, biosphere, and geosphere). For example, the processes of the atmosphere impact weather events and climate change; these, in turn, impact the amount of water present on a slope, which can trigger mass wasting. The processes of the hydrosphere, such as water erosion and undercutting of slopes, can trigger mass wasting as can the biosphere—plants that stabilize slopes and animals that destabilize slopes. Processes of the geosphere, such as earthquakes, also can trigger a mass-wasting event. |
|
What is a major controlling force of mass movements? |
Gravity is the major controlling force of mass wasting. Mass movement occurs if gravitational force is greater than the resisting strength of a rock. The size of the gravitational strength is greater on steep slopes. Several processes can change the slope, friction or cohesion of a mass of rock or sediments and cause the slope to be unstable. The instability can trigger mass movement. The triggers include water saturation, vegetation cover, over steepening slopes, and vibrations from earthquakes. Even though each mass wasting type could be triggered by multiple factors, each has its own unique characteristics in terms of material constituents, angle of movement, and rate of movement. Hence, triggers for each mass wasting type are somewhat different. |
|
Of the following, which is not an example of Earth’s external processes and/or external process-driven phenomena? A.wind |
B.volcanoes |
|
All modification of Earth’s outer surface is initiated by which of the following processes? A.weathering |
A.weathering |
|
Of the responses provided, which is the predominant source of energy for most external processes that operate on Earth? A.the Sun |
A.the Sun |
|
Earth’s surface is subjected to unusually high rates of weathering. The Moon and some of the inner planets of our solar system are also subject to surface weathering, but at much slower rates. Which of the following statements most reasonably explains Earth’s uniquely rapid weathering rates? A.Earth has an oxygen-bearing atmosphere. |
D.Earth has running water at the surface. |
|
Once weathering begins and particles are produced, which factor is most influential in moving them around Earth’s surface? A.the Sun |
E.gravity |
|
Of the following processes, which is not an example of mechanical weathering? A.thermal expansion |
D.oxidation |
|
Considering the following list, which is not an example of chemical weathering? A.oxidation |
B.exfoliation |
|
Pre-existing rocks are broken down into smaller particles by which of the following processes? A.unloading |
A.unloading B.thermal expansion D.frost wedging |
|
In temperate and polar regions, the accumulation of talus slopes at the base of steep, rocky cliffs is most often attributed to which of the following processes? A.frost wedging |
A.frost wedging |
|
The production of tabular slabs of rocks caused by unloading of material overlying igneous bodies is known as _____. A.sheeting |
A.sheeting |
|
In the accumulation of particles in a talus slope, which of the following influences moves particles to their resting place? A.gravity |
A.gravity |
|
Mechanical weathering is a significant factor in the breakdown of rocks. Which of the following factors enhances the effectiveness of further weathering as particles are created? A.increased surface area of the particles |
A.increased surface area of the particles |
|
Which of the factors listed below does not influence the rate of chemical weathering? A.mass of rock available |
A.mass of rock available |
|
In what way does the amount of mechanical weathering that has taken place influence the rate at which chemical weathering occurs? A.Chemical weathering can only work on small particles produced by extensive mechanical weathering. |
E.Mechanical weathering increases the surface area exposed to chemical weathering. |
|
In the silicate minerals, there is a correlation between chemical weathering and Bowen’s Reaction Series. What is the relationship? A.Silicate minerals that form at lower temperatures are more susceptible to chemical weathering. |
D.Silicate minerals that form at the highest temperatures are most susceptible to chemical weathering. |
|
In many older cemeteries, you can often find headstones made of slate. In viewing these headstones today, the lettering is as sharp and clear as the day it was cut. However, many marble headstone inscriptions are illegible. What property of slate allows it to survive the test of time? A.Slate monuments are placed in more out-of-the-way sites. |
C.Clay minerals in the slate make it extremely resistant to weathering. |
|
How are caves formed? |
Water flows in Earth’s subsurface through cracks and pore spaces of rocks and soil. This groundwater erodes rock from within because the water is naturally acidic; rocks that are more susceptible to dissolution erode more rapidly. Limestone is more susceptible to being dissolved, as compared to other rocks, and this is the reason why caves are most often formed within this rock type. Limestone is a sedimentary rock composed of the mineral calcite. Calcite forms from the accumulated shells of dead marine organisms, even though limestone can be found far inland. This can occur because environments change over time, sea level fluctuates, and tectonics moves rocks long distances. Calcite is one of the major constituents of cave features. Two common landscapes are associated with limestone dissolution: 1)Caves are the result of limestone dissolution in the subsurface. 2)Karst topography is the result of rock dissolution on the ground surface. |
|
What is a common denominator between caves and Karst topographies? |
Dissolution of rocks is the common denominator in both the aboveground karst topography and the below ground caves. Precipitation is the driving force, meaning that caves and karst topography are expected where (1) there is limestone or other dissolution-susceptible rock, and (2) the region receives a large amount of precipitation. |
|
What are some common cave formations? |
Caves are erosional features, although depositional features form within them. Flowing and dripping water leave behind calcium carbonate, which is the precipitate of limestone dissolution. This precipitate in turn creates a form of limestone called travertine that is often white or cream-colored. Where and how these precipitates are deposited depends on how the water is dripping or flowing at a given location within the cave. Geologists have identified common formations within caverns, which are: Crystal formations that grow from the ceiling of a cave are called stalactites. These features have a cylindrical or conical shape and are formed as water leaves behind calcium carbonate when it is dripping off the ceiling and conical structures. Conversely, formations that grow from the floor of a cave are called stalagmites and are formed as water leaves behind calcium carbonate when it drips onto the floor or conical structure. Columns are stalagmites and stalactites that have joined. A flowstone forms where water flows on the walls or floor of a cave. The result is a sheet-like feature that is typically whitish or semi-translucent. |
|
How does acidic water play a role in cave formation? |
As described in the introduction, naturally acidic rainwater plays an important role in cave formation. Sinkholes develop on the ground surface as limestone dissolves. Cracks and crevices form along with sinkholes. With flowpaths now established from the surface to underground, rainwater passes into the subsurface. Eventually enough rock is dissolved so that a large airspace is opened, resulting in a cave. Formations begin developing once airspace is created. The action of water dripping and flowing in this airspace is what allows these formations to "grow." Caves often form within limestone rock at about the elevation of the water table. The elevation of the water table changes over time, which allows caves to expand vertically once the cave is established. |
|
How do Karst topographies form? |
karst topography exists because some minerals dissolve when they come into contact with rainwater. Minerals that contain calcium carbonate are especially susceptible to dissolving. Sinkholes and springs are common karst landforms that have the following characteristics: Sinkholes can develop slowly where rainwater infiltrates the dissolving soil and rock, slowly lowering the ground surface of an area. In these instances, sinkholes are shallow with gently sloping sides. Sinkholes can also form rapidly and catastrophically when the cave ceiling collapses, resulting in deep sinkholes with steep walls. Rainwater in karst landscapes flows on the surface differently than other types of terrain. Streams are fewer and less developed in karst areas because water readily infiltrates the ground. Limestone dissolution is often not spatially uniform. In some circumstances, nonuniform dissolution can lead to the formation of tower karsts, which are large structures of rock that have dissolved at a much lower rate than the surrounding rock that has eroded away. |
|
Which of the following is true about karst landscapes? A.Sinkholes form from the same process as cave formations: the dissolution of minerals. |
A.Sinkholes form from the same process as cave formations: the dissolution of minerals. C.Karst topography erodes at different rates, meaning that tall karst towers might form. |
|
Which of the following is NOT used to determine whether a volcanic eruption is expected? |
Atmospheric pressure decreases. |
|
Volcanoes associated with high viscosity magma are usually less dangerous than those with more freely flowing magma. |
False |
|
Which volcano type is the most highly explosive? |
Composite volcano |
|
What is a pyroclastic flow? |
a dense, destructive mass of very hot ash, lava fragments, and gases ejected explosively from a volcano and typically flowing downslope at great speed. |
|
Which of the following volcanic hazards is responsible for the most deaths? |
Pyroclastic flows |
|
Which of the following is NOT true of caldera eruptions? |
Caldera eruptions have occurred in the United States in geologic history. |
|
Tephra can come in many different sizes from dust to large size bombs. |
True |
|
On which of the following plate boundaries are volcanoes NOT typically found? |
Transform Boundaries |
|
Volcanoes can cause tsunamis. |
True |
|
Why are so many volcanoes found around the "Ring of Fire" in the Pacific Ocean? |
The Ring of Fire is a ring of volcanoes around the Pacific Ocean that result from subduction of oceanic plates beneath lighter continental plates. Most of the Earth’s volcanoes are located around the Pacific Ring of Fire because that the location of most of the Earth’s subduction zones. |
|
What distinguishes upstream floods (flash floods) from downstream floods? |
Upstream: short lag time, very rapid rise in water level, dangerous Downstream: long lag time, not as dangers but can do substantial property damage |
|
What is the stage of a river? |
River stage is an important concept when analyzing how much water is moving in a stream at any given moment. Stage is the water level above some arbitrary point, usually with the zero height being near the river bed, in the river and is commonly measured in feet. |
|
What are some things that governments can do to minimize the damage from floods? |
All of the above are things that governments can do to minimize the damage from floods. |
|
How does urbanization influence a river or stream? |
It increases the magnitude, frequency, and rate of the water flows to a the river, it also decreases stream flow during dry season |
|
All areas of the U.S. have some risk of flooding. |
True |
|
Which of the following affect whether a river will flood? |
E) All of the above affect flooding |
|
Paving over land decreases the amount of flooding because water can’t soak into the pavement as well as in the soil. |
False |
|
There are some places that have too high a flood risk for people to rebuild, and these homeowners would be better off if they allowed the government to buy them out. |
True |
|
What is the floodplain? |
an area of low-lying ground adjacent to a river, formed mainly of river sediments and subject to flooding. |
|
Which homes built on the floodplain are most likely to be washed away? |
Those on the floodway |
|
If you live on the 100-year floodplain, you will only have a flood once every 100 years. |
False |
|
Where does a meandering river run the fastest? |
On the outside of a bend. |
|
Why is the calculation of a recurrence interval for floods important? |
It tells you how often on average floods of certain sizes occur, it can be used to help city planners decide where and where not to build, it can give homeowners help in making decisions about purchasing flood insurance |
|
What areas are at risk of flooding? |
Everywhere? |
|
Flooding is the number one natural disaster to affect the United States in the last century. |
True |
|
Which of the following human activities can decrease the incidence of mass wasting? |
Improving drainage from the slope |
|
How does urbanization increase incidences of landslides? |
– the larger the population the more likely to cause destriction – more housing is being developed on slopes causing it to destabilize |
|
Constructing roads on slopes decreases the incidence of landslides because asphalt generally does not let water soak into the ground. |
False |
|
Slopes that have been cleared of native grasses and other vegetation become more stable. |
False |
|
Which of the following does not contribute the failure of a slope? |
Sun exposure |
|
Would adding mass to the top of a slope in the form of houses or buildings make the mass or less likely to slide? |
It would make it more likely to slide because the houses add weight to the slope making it more unstable. |
|
Which of the following is the most important driving force in landslide? |
Weight of the slope in the downslope direction |
|
Which of the following environments are NOT susceptible to mass wasting? |
Relatively flat-lying area |
|
A mudflow is not usually dangerous because it doesn’t move very quickly. |
False |
|
Which of the following is not a way in which water contributes to slope failure? |
Water adds cohesion between the grains of the soil causing it to become unstable. |
|
What is NOT an indication that there are expansive soils in an area? |
Large circular holes with broken pieces of rock at the bottom. |
|
Sinkhole formation is influenced by dramatic changes in the water table level that happen during wet and dry seasons. |
True |
|
What is subsidence? |
the gradual caving in or sinking of an area of land. |
|
What is karst topography? |
A landscape that is characterized by numerous caves, sinkholes, fissures, and underground streams. Karst topography usually forms in regions of plentiful rainfall where bedrock consists of carbonate-rich rock, such as limestone, gypsum, or dolomite, that is easily dissolved. |
|
Which of the following is a correct match between climate and risk? |
Expansive soils and areas with distinct wet and dry seasons |
|
What is the most important mineral that characterizes expansive soils? |
Clay |
|
Areas with extensive limestone formations are particularly vulnerable to sinkholes and caves. |
True |
|
Salt mines can be places for land subsidence because salt is dissolved in water leaving behind cavities for water to pool. |
True |
|
How are sinkholes related to water pollution? |
D.Sinkholes provide a quick route for polluted surface water to contaminate groundwater. |
|
Which of the following does NOT cause ground subsidence? |
E.Creation of permanently frozen ground where no thawing ever occurs |
Share This
Flashcard
