Geol105 Exam 2
Slumping
is sliding along a curved slip plane producing slump blocks
Sliding
is the downslope movement of a coherent block of earth material along a planar slip plane
Soil Horizon
layers or zones of soil
Basaltic Lava
lower viscosity and higher eruptive temperatures, are the fastest and can move 15-35 km per hour near the vent. Most abundant type of lava
Channelization
straightening, deepening, widening, clearing and/or lining existing stream channels are methods of channelization. Objectives include engineering technique include controlling floods and erosion, draining wet lands and improving navigation
Flooding
natural process of overbank flow
Resisting Forces
oppose movement of materials down a slope
Sinkhole
pits or void space that is relatively close to the surface
Safety Factor
slope stability is evaluated by computing a safety factor. Defined as the ratio of the resisting forces to the driving forces. Greater than 1 = safe. Less than 1 = slope failure can be expected.
Soil
solid earth material that has been altered by physical, chemical and organic processes
100 Year Flood
statistical assessment that a given event has a 1 in 100 chance of occurring in any year. 1% chance.
Floodplain Regulation
the objective is to obtain the most beneficial use of floodplains, while minimizing flood damage and cost of flood protection
Weathering
the physical and chemical breakdown of rocks and the first step in soil development
The erosion process in a river is directly related to
the velocity of the flow
Debris Flow
thick mixtures of mud, debris and water. Can move slowly or rapidly depending on the conditions
Subsidence
type of ground failure characterized by nearly vertical deformation, or the downward sinking of earth materials
Flash Flood
typically occur in the upper part of the drainage basin. Generally produced by intense rainfall of short duration over a relatively small area.
Unified Soil Classification System
widely used in engineering practice and thus the evaluatation of hazards
Pyroclastic Deposit
Accumulation of tephra forms a pyroclastic deposit that can be cemented or fused to form a pyroclastic rock.
True or False: A saturated soil is more resistant to landslides that a dry soil
False
True or False: Delaware is unlikely to experience significant flooding in the future.
False
True or False: Like earthquakes, volcanic eruptions occur without warning and, although there are precursors, they cannot reliably be used to determine what is going on beneath the ground (hint: think of what scientist were able to do in during the Pinatubo eruption)
False
True or False: Magma and lava are basically the same thing
False
True or False: Mudflows or lahars associated with volcanoes do not usually cause much damage in a volcanic eruption because they are constrained to river valleys.
False
True or False: Permeability describes the ability of materials of storing large amount of water
False
True or False: Shaking from Earthquakes is not a trigger for landslide
False
True or False: Sinkholes usually form when the ground becomes wet and things sink into them after a big rainstorm.
False
True or False: Soil erosion is not a present day problem in the US
False
True or False: The U.S. Midwest has relatively low risk for landslides mainly because the soils are extremely compacted and therefore strong.
False
True or False: The longitudinal profile of most streams is an upwardly curving line.
False
True or False: The main societal impact of soil erosion is that the eroded soil ends up filling our water reservoirs and diminishes our drinking water supply.
False
True or False: Unfortunately, volcanoes do not give any signs or indications of when they might erupt.
False
True or False: the water table is a surface that divides the unsaturated zone from the saturated zone and never intersect the topographic surface.
False
A ____________ is a relatively flat lowland that borders a river, usually dry but subject to flooding every few years
Floodplain
What natural hazards is the number 1 disaster in the United States in terms of lives lost over the past century?
Floods
How is the incidence of landslides expected to change in the future?
Incidence of landslides will increase
How would a river in an area changed from forest to farmland react to changes?
Increased amounts of sediment would increase the gradient of the stream.
What is the best reason why most lava flows aren't a threat to human life?
Lava flows usually don't flow very quickly, people can outrun them
C Horizon
Lies Directly over the unaltered parent material and consists of parent material partially altered by the weathering process
Why are so many volcanoes found on the Ring of Fire around the margin of the Pacific Ocean?
Many subduction zones occur there.
Soils on the central and high plane in the US are known as
Mollisols
Channel Pattern
Most common patterns are braided and meandering. Can be seen from an airplane
Where on a river would you most likely find point bars?
On the inside of a bend
Where does a meandering river run the fastest?
On the outside of a bend
Decompression Melting
One way magma is formed. Occurs when the overlying pressure exerted on hot rock within the asthenosphere is decreased. occurs at divergent plate boundaries, continental rifts and hot spots
True of False: Minerals that forms last in the Bowen series tend to be generally more stable and resist better to weathering
True
True or False: The distinct layers of a soil are called soil horizons.
True
True or False: A narrow river usually runs faster than a wider one.
True
True or False: Composite volcanoes can have a long dormant period in which people can forget that they were ever once active volcanoes.
True
True or False: Construction of levees can actually make floods worse in areas upstream and downstream from the construction.
True
True or False: If levees are built along a river to protect a town such as St. Louis, then the narrowing in the width of the channel between the levees can cause the floodwater to back up and increases the level of flooding upstream.
True
True or False: In purchasing a house, some steps can be taken to determine whether it is susceptible to a landslide hazard.
True
True or False: Insurance and building codes are two important ways that the government can protect property from disaster in a flood.
True
True or False: Landslides are an example of a geologic hazard in which damage can be greatly reduced if appropriate measures are taken in the area of public policy and landslide control.
True
True or False: Magma with a higher silica content will also have a higher viscosity.
True
True or False: Meandering rivers migrate over time across their floodplain and actually create their floodplains by eroding and depositing sediment over time.
True
True or False: People can stabilize a slope through increased drainage and slope supports.
True
True or False: Scientists can use information about earthquakes to determine when a volcano is likely to erupt.
True
True or False: Sinkholes and caves involve extensive dissolution of rocks due to changing levels of groundwater.
True
True or False: The mineral composition of soils has a great influence on the type of subsidence or volume changes that will occur.
True
True or False: The recurrence interval for a river in a natural system to reach bankfull stage is about one to two years.
True
True or False: The result of chemical weathering is a change in the composition of the original material
True
True or False: There are some places that have too high a flood risk for people to rebuild; these homes usually are better off abandoned.
True
True or False: despite the fact that modification of the natural course of a river by engineering its course is always a major impact on the surrounding environment, some drainage projects are beneficial in flood control.
True
True or False:One indication of a rock fall is an accumulation of rocks at the base of a cliff.
True
R Horizon
Unaltered parent material, consolidated bedrock that underlies the soil
Creep
Very slow flowage. Progressive tilts telephone poles, fences and tree trunks.
Frost Heaving
Volume increase from freezing causes an upward movement of soil particles and the land surface through this process
Recurrence Interval of a Flood
average time between flood events that are of equal or greater magnitude
Mass Wasting
comprehensive term for any type of downslope movement of earth materials.
How good of an indicator is soil color in categorizing the soil horizon?
.Reasonably good. Sometimes color can be misleading, but usually it can give you a good idea.
If the average velocity of streamflow is 5 feet per second, and the cross-sectional area of the stream channel is 20 square feet, what is the stream discharge? (assume that you do not change any of the units of either velocity or area when you perform this computation)(just give the number WITHOUT units)?
100
If the geologic mapping of a particular volcano shows that violent explosive eruptions occurred in the years 1600, 1620, 1680, 1800, 1805, 1895, 1910, 1955, and 2000, the recurrence interval for this volcano is ______
50 years
The U.S. National Flood Insurance Program, and FEMA regulations, require participating communities to do what? (select all that apply) A. To prohibit all new construction within the floodway B. To cover at least half the cost of the insurance. C. To map the 100 year floodplain to determine flood hazard areas. D. To build levees to control river flow
A & C
The watershed (or drainage basin) is (Select all that apply): A. the area that drains into a specific river B. shared among 2 or more different rivers that end into the ocean C. limited by the drainage divide D. an administrative boundary that has nothing to do with the hydrology of the river itself
A & C
Landslide
A downslope movement of rock and soil over a failure surface and under the influence of gravity. Slumps, earthflows, debris flows and debris slides are examples.
What is a pyroclastic flow?
A fast-moving avalanche of hot rock, ash and glass fragments
What would the longitudinal profile of a river flowing from a gentle valley into an ocean look like?
A gently downward sloping line
Snow Avalanche
A rapid downslope movement of snow and ice, sometimes with the addition of rock, soil, and trees.
Karst Topography
A region in which a layer of limestone close to the surface creates deep valleys, caverns and sinkholes.
Cave System
A series of caves produced as water moves downward through limestone. Primary mechanism for forming the caves is through groundwater moving through rock.
Volcanic Crisis
A situation in which the science suggests that a volcanic eruption is likely in the near future.
Factors affecting soil formation are A. Climate B. Parent material (the rock from which they generate) C. Biological action D. Time
A, B, C & D
Measures to prevent soil erosion include: A. Crop rotation B. Contour plowing C. Windbreaker (usually rows of tall trees) D. Runoff control
A, B, C & D
The next time you are in the market to buy a house, you will (select all that apply) A. build or renovate the house to be flood-resistant B. remember what the weird Italian professor at UD told you about flooding! C. check to make sure that it isn't located on the 100 year floodplain. D. make sure that you have flood insurance!
A, B, C & D
Although we focus on the hazardous aspects of volcanoes in this class, they also provide significant natural service functions. Which of the following are considered benefits of volcanic activity? (Choose all that apply.) A. Ore deposits B. A reduction of carbon dioxide in the atmosphere leading to global cooling. C. Nutrient rich soils D. Potential for geothermal power
A, C & D
Rills and Gullies are: A. Deep incisions produces by running water that scour and erode the soil B. The effect of strong wing blowing over plowed soil C. Deep incisions produced by incorrect practice of plowing D. Shallow incision in soils that are easy to stop and mitigate
A. Deep incisions produces by running water that scour and erode the soil
In an undisturbed environment, soils... A. Evolve through time and increase in thickness B. Evolve through time but their total thickness remain constant C. Do not evolve through time and their thickness remain constant D. Do not evolve through time and decrease in thickness
A. Evolve through time and increase in thickness
Which of the following factors contributes the most to the elevated flood hazards in North and South Dakota, along the Red River? A. Ice and ice dams B. steep slopes C. deforestation D. urban development
A. Ice and ice dams
After a watershed is urbanized, flood discharges typically A. Increase B. Decrease C. Stay the same - there is no change
A. Increase
Intense farming is potentially dangerous for soil conservation because A. It disrupt the natural vegetation cover and expose the soil material B. It deplete the soil of nutrients C. It breaks the minerals that hold the soil in place D. It add water to the soil, causing unnatural runoff
A. It disrupt the natural vegetation cover and expose the soil material
Which of the following states has the greatest percentage of karst topography? A. Kentucky B. Nevada C. Nebraska D. Louisiana E. Alaska
A. Kentucky
Karst is a process that mostly affects: A. Limestones in humid climate B. Limestones in dry climate C. Granites in dry climate D. Granite in humid climate
A. Limestones in humid climate
In which "reservoir" of the Earth's hydrological cycle is most of the world ?s water stored? A. oceans B. atmosphere C. lakes and rivers D. glaciers E. groundwater
A. Oceans
Which one of these eruptions is likely to produce a tall column of steam, ashes and pyroclastic that can reach the upper layer of the atmosphere? A.Plinian eruption B.Hawaiian eruption C.Pelean eruption D.None of the above
A. Plinian Eruption
Effects of karst processes include A. Sinkholes B. Mudflows C. Creep D. Avalanches
A. Sinkholes
Most of the explosive magma produced on Earth is produced by the process of subduction and is andesitic to rhyolitic in composition. Your book discusses the three processes by which a rock can melt to form a magma. Which of the following processes is responsible for producing the andesitic/rhyolitic magma seen at subduction zone volcanoes? A.The addition of water to the hot rock of the mantle. B.The increase in temperature as heat is added to hot rocks in the Earth's crust. C.The decrease in pressure on the hot rock in the mantle as it upwells toward the surface. D.The increase in pressure on the hot rock of the mantle during downwelling.
A. The addition of water to the hot rock of the mantle
Adding earth material to the lower part of a slope which has the potential for a landslide would A. increase the resisting force. B. decrease the resisting force. C. increase the driving force. D. decrease the driving force.
A. increase the resisting force.
Urbanization has several impacts on the natural processes of flooding along a river. Building or paving over land creates an impervious or impermeable surface that A. increases the runoff directly into the river, thereby increasing the flooding. B. increases the infiltration, thereby decreasing the flooding. C. traps water, keeping it from reaching the river, thereby creating mini-lakes. D. increases the interception, thereby decreasing the flooding.
A. increases the runoff directly into the river, thereby increasing the flooding.
Where are the majority of the active volcanoes in the United States?
Alaska
Talus
An accumulation of rock debris at the base of a cliff
In the following list of magmas, only one is likely to explode - the others will produce lava flows or spatter to form small cinder cones or ooze out to form lava domes. Which one of the following magmas is most likely to produce an explosive volcanic eruption when it reaches the Earth's surface?
An andesitic magma with gas.
Which area of the U.S. has a highest incidence of landslide activity?
Appalachian Mountains
Spring
Areas where groundwater naturally discharges at the land surface.
Lateral Blast
Ash, gas and rock fragments are blown horizontally from the side of the mountain. These eruptions can eject debris at tremendous speeds and can be extremely destructive.
Where is the majority of lava extruded?
At divergent plate boundaries
Which is NOT a location where volcanoes are found? A. Alaska B. Central United States C. Hawaii D. Pacific Northwest United States E. Yellowstone National Park
B. Central United States
Which of the following statements describes subsidence at the central (San Joaquin) valley of California? A. Gradual subsidence occurred over several decades due to the deep subsurface withdrawal of oil and gas. B. Gradual subsidence occurred over several decades due to the withdrawal of groundwater mainly for irrigation purposes. C. Rapid subsidence occurred due to a collapsible soil. D. Rapid subsidence occurred due to a collapse sinkhole.
B. Gradual subsidence occurred over several decades due to the withdrawal of groundwater mainly for irrigation purposes.
A mature soil... A. Is usually very thin B. Has numerous recognizable horizon C. Is composed by a layer of organic matter sitting on top of fractured rock D. Is very light in color
B. Has numerous recognizable horizon
1.0/ 1.0 Points Which of the following volcanic areas are located at a mantle hotspot? A.Mt. St. Helens and Mt. Fuji B.Hawaii and Yellowstone C.Augustine and Pinatubo D.Mt. Rainier and Vesuvius
B. Hawaii and Yellowstone
Which of the following environments has the most explosive volcanoes? A. Hotspots in the ocean B. Hotspots on land C. Continental rift zones D. Mid-ocean ridges E. Subduction zones
B. Hotspots on land
Which of the following human activities can DECREASE the incidence of mass wasting? A. Grading surfaces to increase the slope B. Improving drainage from the slope C. Removing vegetation such as trees and grass from the slope D. Cutting out a section at the base of a slope to build houses E. Building a road on a slope
B. Improving drainage from the slope
The effect of physical weathering may enhance the action of chemical weathering because... A. It breaks the rock in small pieces and makes is softer B. It fractures the rock and offer more surface for chemical reactions C. Produces new mineral that are then attacked by chemical weathering D. All of the above
B. It fractures the rock and offer more surface for chemical reactions
Which of the following involves downslope movement of a coherent, usually large block of earth material along a planar surface? A. Rock fall B. Rock slide C. Creep D. Earthflow E. Slump
B. Rock slide
Which of the following statements about sinkholes is FALSE? A. Sinkholes can occur where there is soluble rock near the surface. B. Sinkholes are usually found in remote and swampy areas. C. Sinkholes are a widespread and costly hazard in the U.S. D. Sinkholes can cause damage to roads and bridges. E. Sinkholes can reveal themselves during times of drought.
B. Sinkholes are usually found in remote and swampy areas.
The occasional curved shape of the trunk of trees in forests is an evidence of fast acting landslides A. slumping B. soil creep C. rock slides D. intense farming
B. Soil Creep
In which "reservoir" of the Earth's hydrologic cycle is most of the world's freshwater stored? A. oceans B. glaciers C. lakes and rivers D. groundwater E. atmosphere
B. glaciers
Intense use of groundwater in areas like California or Nevada, has caused ground subsidence in the order of A. a few centimeters B. many meters C. 20-40 meters D. hundreds of meters
B. many meters
A landslide will start to move if... A. the shear stress is perpendicular to the surface B. the shear stress exceed the friction on the slope C. the weight of the rocks exceed the friction on the slope D. the inclination of the slop equals the angle of repose
B. the shear stress exceed the friction on the slope
Which of the three common lavas has the lowest viscosity?
Basaltic
Which of the following loads are most likely to consist of heavy rocks and boulders?
Bed Load
Which would increase during a flood, discharge or velocity?
Both discharge and velocity will increase because there is more water flowing and it is flowing faster.
Cinder Cone
Built up by the accumulation of tephra near a volcanic vent, cinder cones are relatively small volcanoes composed of nut-to-fist sized pieces of vesicular red or black lavas
What two parameters are plotted in a hydrograph?
Discharge vs. Time
A soil is A. A mixture of sand and silt B. A mixture of silt and clay and sand C. A mixture of air, minerals, water and organic matter D. A mixture of air water and organic matter
C. A mixture of air, minerals, water and organic matter
Which of the following is the slowest mass wasting process? A. Avalanche B. Slump C. Creep D. Earth flow E. Fall
C. Creep
Which of the following is NOT an important factor in the stability of a slope? A. Slope steepness B. Climate C. Direction of Sun exposure D. Vegetation E. Water
C. Direction of Sun exposure
Which of the following is FALSE about the effects of landslides? A. Landslides can cause flooding when rivers are blocked. B. Landslides can bury people in debris. C. Landslides, because of the damage they normally inflict, offer no natural service functions. D. Landslides can break utility wires and disrupt travel. E. Landslides can cause damage to homes and roads.
C. Landslides, because of the damage they normally inflict, offer no natural service functions.
In the presence of layered bedrock, the local geology can influence and favor landslides when: A. The rocks are horizontally stratified B. The rocks are inclined toward the inside of the mountain C. The rocks are inclined in the direction of the slope D. Never. Local geology has no influence on landslide. As long as there is a weak layer of rocks, landslides will happen.
C. The rocks are inclined in the direction of the slope
The angle of repose is A. The angle at which Prof. Berti sits, after class B. The slope of a loose, wet sediment C. The slope of a pile of loose, dry material D. The inclination of an actively eroding bank of a river
C. The slope of a pile of loose, dry material
Yellowstone is considered to be a "supervolcano" - capable of producing an eruption several thousand times the size of the Mt. St. Helens eruption. Yet, most people don't even realize it is a volcano - all you see is a big hole in the ground! This type of volcano is known as a
Caldera
Volcanic Dome
Characterized by high viscous magma
Volatiles
Chemical compounds that evaporate easily and exist in a gaseous state at the Earth's surface.
What is the most important soil particle that characterizes expansive soils?
Clay Minerals
What is the main difference between collapse sinkholes and solutional sinkholes?
Collapse sinkholes involve the surface rock and soil falling into an underground cave whereas solutional sinkholes form by downward dissolution from the bedrock surface.
Soil Taxonomy
Comprehensive and systematic classification of soils. Emphasizes the physical and chemical properties of the soil profile
Composite Volcano
Cone shaped. Magma is generally more viscous and has a higher volatile content than shield volcanoes, resulting in a mixture of explosive activity and lava flows. AKA stratovolcanoes, composed of layers of both pyroclastic deposits and lava flows. They erupt a variety of lava types from basalts to lavas that are intermediate between andesite and rhyolite. Examples - Mt. Fuju in Japan and Mount St. Helens & St. Rainers in the US.
O Horizon
Contains highly concentrated organic material. Consists of plant litter and other organic material.
A Horizon
Contains highly concentrated organic material. Contains a good deal of both organic and mineral material. Below O Horizon
Ash Fall
Create several hazards including vegetation destroyed, contamination of surface water, structural damage to buildings as the ash builds up on it, irritation of the respiratory system and eyes, engines of jets may "flame out"
Which of the following is FALSE about caldera eruptions? A. Caldera eruptions are extremely violent in nature. B. Caldera eruptions are very rare. C. Caldera eruptions erupt enough ash to potentially alter global climate. D. Caldera eruptions result in towering volcanic mountains. E. Caldera eruptions have occurred in the United States in geologic history.
D. Caldera eruptions result in towering volcanic mountains.
Which of these factors is not a direct responsible for ground subsidence? A. Underground mining B. Earthquakes C. Oil extraction D. Dam construction
D. Dam construction
Which one of the following is NOT mechanical weathering A. Frost wedging B. Dissolution C. Exfoliation D. Biologic action
D. Dissolution
Which of the following is the best match between climate and soil hazard? A. Solution sinkholes and arid climates B. Collapsible soils and humid climates C. Solution sinkholes and polar climates D. Expansive soils with distinct wet and dry seasons E. Collapsible soils and polar climates
D. Expansive soils with distinct wet and dry seasons
Which of the following volcanic hazards is responsible for the most deaths? A. Lava flows B. Ash falls C. Poisonous gases D. Pyroclastic flows
D. Pyroclastic flows
Along the coast, in proximity of major river, a beach is usually made by a very high concentration of quartz sand because.... A. All the other mineral are lighter in weight and get washed away more easily by the ocean waves B. This is not true. Quartz is only on the top layer but there are other minerals just a few inches below the surface C. Quartz is more resistant to the UV ray and it doesn't get sunburn D. Quartz is more resistant than other minerals and is what remains after the weathering processes have disintegrated and dissolved the sediments
D. Quartz is more resistant than other minerals and is what remains after the weathering processes have disintegrated and dissolved the sediments
Which one of the following is not a fast mass movement? A. Rock fall B. Slump C. Debris flow D. Solifluction
D. Solifuction
Which of the following is NOT an example of how urbanization influences a river or stream? A. Urbanization decreases rainwater infiltration into the ground and therefore increases the frequency of floods. B. Urbanization decreases rainwater infiltration into the ground and therefore increases the magnitude of floods. C. Urbanization decreases flood lag time by the network of street sewers. D. Urbanization increases rainstorm frequency and therefore increases the frequency of floods.
D. Urbanization increases rainstorm frequency and therefore increases the frequency of floods.
Which of the following factor did not played a role in triggering or facilitate the landslide in Oso, WA that we examined in class? A. extensive logging B. river incision C. intense precipitation D. shaking from seismic event
D. shaking form seismic event
If you dip a glass of water into a river and passed the water through a very fine sieve that blocked all sediment grains from passing through, what will you be left with?
Dissolved Load
What are two causes of the subsidence of New Orleans?
Draining of organic-rich soil and loss of supply of fine sediments by rivers
How do drains help to prevent landslides?
Drains divert water away from the slope.
In which of the following cases would you expect the LEAST amount of flooding due to a rainstorm? Assume all areas receive similar amounts of rainfall in the rainstorm and there are no flood control measures in any of the areas. A. An area where soil is already saturated due to previous recent thunderstorms B. An area where the ground is frozen C. A short duration rainstorm falling on an area that is typically very dry such as a desert D. A city with many houses, paved roads, and sidewalks E. A long duration rainstorm falling on an area that consists of forest, grasslands, and no human development.
E. A long duration rainstorm falling on an area that consists of forest, grasslands, and no human development.
Which of the following natural disasters is linked in some way with landslides? A. Earthquakes B. Floods C. Volcanoes D. Tsunamis E. Earthquakes, floods, volcanoes, and tsunamis all have some connection with landslides.
E. Earthquakes, floods, volcanoes, and tsunamis all have some connection with landslides.
Which of the following is NOT a factor in how urbanization increases the incidence of landslides? A. Trees and grasses are removed, leaving the land susceptible to erosion. B. Roads are constructed altering the permeability of the land. C. Buildings are placed on slopes, increasing the weight on the slope. D. Roads are cut at the base of slopes increasing instability. E. Flood control measures prevent river flooding, which increases the incidence of landslides.
E. Flood control measures prevent river flooding, which increases the incidence of landslides.
Which statement is FALSE about the effects that floods can have? A. Floods can supply nutrients to soils for farming. B. Floods can clear ecosystems of debris. C. Floods can supply sediments to build up the elevation of land. D. Floods can bring nutrients to ecosystems. E. Flooding has no positive effects; it is always bad for human interests.
E. Flooding has no positive effects; it is always bad for human interests.
Which of the following is FALSE about magma? A. Most magmas come from melting of the asthenosphere. B. Some magma comes from rocks melted through decompression. C. Adding volatiles, such as water, to rock decreases its melting point and makes it easier to melt. D. Some rocks are melted from magma that is rising from deep within the Earth. E. Tectonic plates move around on an underground ocean of magma.
E. Tectonic plates move around on an underground ocean of magma.
Which of the following natural hazards is NOT caused by volcanoes? A. Climate change B. Landslides C. Fire D. Tsunami E. Tornadoes
E. Tornadoes
Which of the following is NOT a sign of a potential landslide? A. Cracks or terraces on hillside B. Area of bare soil or rock on hillside C. Path of cleared vegetation extending down a hill D. Exposed bedrock with layering parallel to slope E. Vegetated slope that has not received rain in two weeks
E. Vegetated slope that has not received rain in two weeks
Which of the following is NOT a way that climate change can contribute to the subsidence problem? A. Permafrost will melt causing subsidence. B. Some soils will dry out causing them to settle. C. Sea levels will rise sinking coastal cities that are already sinking. D. Groundwater levels may rise or fall increasing sinkhole incidence. E. Groundwater will warm, causing a large increase in dissolved limestone and sinkhole formation.
E.Groundwater will warm, causing a large increase in dissolved limestone and sinkhole formation.
If you see a steep cliff with piles of rocks at the bottom, what kind of mass wasting has occurred?
Fall
Falling
Free fall of earth materials, as from the free face of a cliff
Formation of a soil includes processes that acts
From the top, down
What is the stage of a river?
Height of water that is flowing
Where does the majority of soil originate from?
It comes from weathered rock
In buying a house, why should you be wary of tilted telephone poles?
It is a sign of creep
The time that intercourse between the peak of precipitation and the peak of a flood at any given point along the river is known as the ___________.
Lag time
What is the name of a volcanic mudflow?
Lahar
Shield Volcano
Largest volcanoes in the world. Common in the Hawaiian Islands, Iceland, and some islands in the Indian Ocean. Generally nonexplosive because of low viscosity and low volatile content of their basaltic magma. Magma flows down the sides of these volcanoes making the gentle slopes. They are wider than they are tall, but are still among the tallest mountains in the world.
What is the difference between magma and lava?
Magma is found below the Earth's surface, lava is found on the Earth's surface.
Shear Strength
Most common resisting force is the shear strength of the slope material, that is, its resistance to failure by sliding or flowing along potential slip planes
What should you do during a flood?
Move to higher ground away from the river.
Permafrost
Natural condition that may be continuous throughout the soil or in slightly warmer climates, may exist as discontinuous patches or think layers. Consists of particles of soil or sediment that remain cemented with ice for at least two years
Groundwater Mining
Occurs when the amount of water coming to surface in wells and springs exceed the volume that is being replenished through the percolation of rain and surface water
At which plate boundary is more viscous lava found?
Oceanic Subduction Zones
How does pumping oil contribute to land subsidence?
Oil is removed, which removes the buoyant support it provided for the earth material, causing it to be more compacted.
Lahar
Produced when large amounts of loose volcanic ash and other tephra are saturated with water, become unstable and suddenly move downslope. Can occur without an eruption and are generally low-temperature flows
The explosion of magma at the Earth's surface produces what type of volcanic material? (one word)
Pyroclastic
Discharge
Q, the volume of water moving through a cross section of a river per unit time
If you were digging down into a soil, which horizon would you hit last?
R
In the following list of magmas, only one will produce a lava dome - the others will produce lava flows or spatter to form small cinder cones or explode to produce pyroclastics. Which one of the following magmas is most likely to produce a lava dome when it reaches the Earth's surface?
Rhyolitic magma without gas
What type of volcano is found in Iceland?
Shield
The chemical weathering process known as hydrolysis affects mostly which type of minerals?
Silicates
How are sinkholes related to water pollution?
Sinkholes provide a quick route for polluted surface water to contaminate groundwater.
Collapsible Soil
Soil and sediment that are prone to collapsing and lower the land surface
K Horizon
Soil horizon impregnated with calcium carbonate
Frost-Susceptible Soil
Soils that have the potential to move and expand when they freeze. These soils expand because of the 9 percent volume increase that occurs when water changes to ice.
Andesite is most commonly found at what type of plate tectonic setting?
Subduction zones
If you see a concrete wall with several drain holes through it on the side of a roadway, what is its purpose?
Support the base of the slope
What component of the hillslope hydrological cycle provides the most direct control on flooding (pick from one of the following: interception, evapotranspiration, infiltration, groundwater flow, surface runoff)?
Surface Runoff
River
Surface drainage, known as runoff, finds it way to small streams, which may merge to tributaries to form a larger stream = river
Which of the following loads would make a river appear murky or dirty?
Suspended Load
Most of the magma produced on Earth is produced at mid-oceanic ridges (divergent plate boundaries) to form the oceanic crust and is basaltic in composition. Your book discusses the three processes by which a rock can melt to form a magma. What processes is responsible for all this basaltic magma at the ridges?
The decrease in pressure on the hot rock in the mantle as it upwells toward the surface. (Decompression melting)
Floodplain
The flat surface adjacent to the river channel that is periodically inundated by flood water, is produced by the process of flooding
Pyroclastic Flow
The most lethal aspects of volcanic eruptions. They are avalanches of hot pyroclastic materials (ash, rock volcanic glass fragments and gas) that are blown out of a vent and more rapidly down the sides of the volcano
Debris Flow/Mud Flow
The most serious secondary effects if volcanic activity. Known as LAHAR. Debris flows differ from mudflows because they are coarser
If you were in a very cold climate and looking out at an area with many sinkholes and rough terrain, what would you most likely be looking at?
Thermokarst
Expansive Soil
These soils shrink significantly during dry periods and expand or swell during wet periods
Why do cinder cone volcanoes have steep slopes?
They are made from pyroclastic materials that pile up near where they were erupted.
In a region susceptible to sinkhole formation, the most likely times for collapse will be
When groundwater levels are low.
B Horizon
Zone of accumulation, underlies O, A or E horizon and consists of a variety of materials translocated downward from the overlying horizons.
E Horizon
Zone of leaching. Underlies O and A Horizon. Light colored layer that is leached of iron-bearing components.
Andesitic Lava
a lava of intermediate composition that has a higher silica content than basalt, erupts at lower temperatures and is more viscous
Colluvium
a mixture of weathered rock and other debris that is above the bedrock and blow the soil. Usually the plane of weakness for soil slips.
Volcanic Vent
any opening though which lava and pyroclastic debris are erupted
Crater
depressions commonly found at the tops of volcanoes. Form explosively during the eruption, removing the upper portion of the volcanic cone
Flow
downward slope movement of unconsolidated material in which particles move about and mix within the mass, such as earth flows, debris flows or avalanches
Organic Soil
earth material that contains decayed leaves, stems, roots and in colder regions, moss, which soaks up water like a sponge. Mostly decomposed by bacterial decomposition,
Levee
earthen embankments constructed parallel to the river to contain flood waters and reduce flooding
Caldera
gigantic depressions formed during explosive ejection of magma and subsequent collapse of the upper cone
Lava
molten rock that is erupted onto the Earth's surface
Magma
molten rock that is within the Earth
Driving Forces
move earth materials down a slope
Channel Restoration
objective is to create a more natural channel by allowing the stream to meander and where possible to reconstruct variable water-flow conditions with fast, shallow riffles alternating with slow deep pools. Uses techniques including 1) cleaning urban waste from the channel 2) protecting the existing channel banks by not removing existing trees 3) planting additional native trees and other vegetation
Drainage Basin
region drained by a single stream or river. Each stream has its own drainage basin or watershed that collects rain and other precipition
Lava Flow
result when magma reaches the surface and overflows the central crater or erupts from a volcanic vent along the flank of the volcano
Disappearing Stream
surface streams that suddenly disappear on karst landscapes. They flow directly into groundwater system and continue along a subterranean route.