Geology 101 ISU
Which soil horizon is known as topsoil?
A horizon
Where are high-level nuclear wastes from nuclear power plants currently being stored?
In steel-lined concrete containers or pools within the nuclear power plants.
Hydraulic conductivity in soils increases with
Increasing the particle size
What is peak oil?
It is a term for the time that will come when one-half of Earth's oil supply has been extracted and used. It is likely to occur sometime between 2020-2050.
What are the three largest uses of freshwater in the United States?
Largest- thermoelectric power Middle- Irrigation Smallest- Public Supply
What is the health threat from nitrates in drinking water?
Nitrates can cause an anemic condition called "blue baby" in young children.
Identify the 2 environmental concerns associated with hydroelectric power.
Nitrogen gas enriched water can kill fish, Dams cause changes to the natural stream flow, affecting stream biota and productivity.
Why does shale that contains natural gas need to be fractured or "fracked" to extract the natural gas? (Choose the option that best answers the question)
Shale has very low permeability so the rock has to be fractured to open pathways to allow natural gas to move out of the rock
Why is there a "dead zone" in the Gulf of Mexico? What factors and processes create the "dead zone?"
The Mississippi River is draining the runoff from its watershed into the Gulf of Mexico. Much of the drainage basin is agricultural and the runoff contains large amounts of nitrogen from fertilizers. The nutrients supplied to the gulf lead to eutrophication, whereby algae blooms reduce the water quality and oxygenation.
Why did cooling water stop flowing through the Fukushima Daiichi (Japan) reactors in March, 2011? Select the best answer.
The tsunami that followed the earthquake destroyed power lines, cut water lines, and took out the backup diesel generators, leaving no way to supply cooling water to the reactor cores.
What are 2 reasons nuclear reactors require cooling water to flow through them at all times?
To cool the reactor, To generate steam to run the tubines.
A concentration of minerals that can be legally mined at a profit at the current time is called a reserve.
True
Which country uses the most oil? Which country uses the most coal?
United States, China
Beach nourishment _______________.
a coastal engineering method that provides a recreation beach and helps protect coastal properties from erosion by widening the beach
Which volcano is more likely to produce a lahar - a composite volcano like Mt. Rainier in Washington or a shield volcano like Kilauea in Hawaii? Why?
a composite volcano because ash from a pyroclastic eruption could mix with water from melted snow and ice on the summit and form a lahar
What is uniformitarianism?
a concept stating that environmental conditions in the past were the same as those of today
An aquifer with an impermeable layer above and below it is called
a confined aquifer
What is the best description of a '100-year' flood?
a flood that has a 1 in 100 probability (1% chance) of occurring each year
Unconformities represent
a gap in the geologic record
Which of the following statements about obtaining natural gas through the process of hydraulic fracturing ("fracking") is CORRECT?
a horizontal well is drilled into a shale unit, which is then artificially fractured, and the fractures are held open with a mixture of water, sand, and chemicals
What is a theory?
a hypothesis that has withstood extensive testing
When the water table intersects the ground, it will discharge as
a spring
The drawing below shows a cross-sectional view of a subduction zone. An earthquake that occurs at location X has the potential to displace the overlying seawater, causing
a tsunami
Why is it possible for an ecosystem adapted to cool temperatures (algific talus slopes), to thrive in the warm summer climate of Iowa?
air chilled by flowing through fractured and partially dissolved limestone and dolomite bedrock creates a microclimate with cooler temperatures
A group of populations of different species living in the same area with varying degrees of interaction with each other is
an ecological community
An aquifer is earth material capable of storing and supplying groundwater at a useful rate. A confined aquifer is formed when a confining or impermeable layer restricts the upper surface of the zone of saturation. A cone of depression forms when the surface of the water table is drawn down by a pumping well.
aquifer, confined aquifer, cone of depression
Synthetic organic chemicals like PCBs, dioxins, MTBE, etc.
are toxic, accumulate in the food chain, don't break down easily in the environment
Why is human population growth considered an environmental problem?
as the population increases, more resources are needed and more waste is produced, causing greater amounts of disruption to the environment
A lahar is produced when
ash and other pyroclastic ejecta become saturated with water
In an ionic bond,
atoms are joined by negatively or positively charged ions
Shield volcanoes have gently-sloping sides because they are dominated by eruptions of runny
basalt
In the next few decades, water resources in the Colorado River Basin are expected to
be stressed even further due to anticipated population growth
Why are the impacts of coastal hazards such as erosion, storm surge, and flooding so great?
because densely populated areas are located at or near the coasts
Biotechnology can help reduce the environmental impacts of mining through
bioleaching of crushed ore, the construction of wetlands to treat contaminated water
What environmental impact does the production of shale gas and tar sands have in common?
both generate contaminated wastewater
In what way can the construction of dams and levees INCREASE flood damage on a floodplain?
by giving a false sense of security that encourages development on the floodplain
Aquifers
can be any Earth material with high porosity and high permeability
An advantage of the Universal Soil Loss Equation is that it
can evaluate the potential impact of conservation practices that control erosion
Limestone is prone to chemical weathering where the rock can dissolve to form caves because it consists of a mineral from the
carbonate group
The maximum number of people Earth can hold without causing prohibitive environmental degradation is called
carrying capacity
The 1991 eruption of Mt. Pinatubo
caused global cooling the next year because incoming solar radiation was scattered off ash particles and aerosol droplets in the atmosphere
The Kissimmee River in Florida needed restoration because of
channelization
How does no-till agriculture reduce soil erosion?
crop residue left on the fields provides a protective cover, it eliminates plowing
How do point bars and cut banks differ from one another in a stream system?
cut banks are sites of erosion, while point bars are sites of deposition
Biochemical oxygen demand reflects the amount of
decaying organic matter in water bodies
Detrital sedimentary rocks differ from chemical sedimentary rocks in that
detrital sedimentary rocks are composed of visible pieces of preexisting rocks, and chemical sedimentary rocks are composed of minerals that evaporate or precipitate from a solution
Which of the following would be considered a point source of pollution?
discharge of industrial wastewater
Which of the following statements about earthquake prediction is CORRECT?
earthquake recurrence intervals are used to make long-term predictions (probabilities over decades of time) for large earthquakes, foreshocks and deformation to the ground surface may occur prior to a large earthquake
In a covalent bond,
electrons are shared between a limited number of atoms
Soil ________ refers to the ease with which soil particles can be moved by wind or water.
erodibility
What phase of mining generally causes the least environmental degradation?
exploration and testing
Crust is consumed at transform boundaries.
false
Desalination is a low-cost, low-energy alternative to conventional water resources.
false
Limestone is a detrital sedimentary rock.
false
The magnitude of an earthquake is a function of how far away you are from the earthquake.
false
What are the possible effects of utility lines (electric power, gas, water, sewer) rupturing in an earthquake?
fires could be sparked by broken electric power and gas lines, and if water lines are also broken, there may not be any way to put them out, loss of functioning water and sewer lines could cause sanitation problems, which may lead to outbreaks of disease
Which type of flood is typically caused by intense rainfall of short duration?
flash flood
Why is flood hazard mapping considered an important step in floodplain management?
flood hazard mapping guides appropriate development in the floodplain
The statistical probability of a flood of a certain magnitude occurring in any given year is referred to as the
flood recurrence interval
What aspect of tropical cyclones tends to cause the greatest death and destruction
flooding from rain, waves, and storm surge
The objective of _____________ is to maximize beneficial use of the floodplain while minimizing flood damage and the cost of flood protection.
floodplain regulation
Some metamorphic rocks are potential environmental hazards because
foliation planes can be planes of weakness in the rock
Gypsum used in drywall and graphite used in pencils
form from sedimentary and metamorphic processes, respectively
Why does acid rain result from fossil fuel consumption?
fossil fuel burning releases nitrogen and sulfur oxides
Strong bedrock, like granite, influences the formation of what types of hillslopes?
free cliff face with talus at the base
How might global warming exacerbate coastal hazards?
global warming will likely be accompanied by sea level rise
What aspect of hillside development has contributed to the frequency of landslides in southern California?
grading of hillslopes to create pads for home construction
One possible explanation for the driving force behind plate motion is slab-pull. This idea calls for
gravity to pull dense oceanic lithosphere into the mantle
A major drawback associated with the use of nuclear energy is
how to dispose of the radioactive waste
Rare earth elements are used in which of the following?
hybrid cars like the Toyota Prius, magnets in wind turbines, computer screens
Which of the following types of renewable energy displaces people and traps sediment so that beaches aren't replenished with sand?
hydroelectric power
How do slides and flows differ?
in a slide, material moves downslope as a coherent block, and in a flow, material mixes and churns as it moves downslope
Sea otter reintroduction in Alaska has led to
increase in kelp forests
If a stream channel is of constant width and depth, how must increased discharge be accommodated?
increased velocity
As a tsunami approaches land, the height of a tsunami wave ____.
increases primarily because the water depth and velocity decreases.
An indigenous ecosystem is one that
is not substantially impacted by humans
The water table
is the boundary between the vadose zone and the saturated zone
Environmental geology
is the study of human interactions with the Earth environment, hazards, and resources and applied geology
The sludge from sewage treatment plants
is used as fertilizer because it contains nitrogen and phosphorus
If magma has a HIGH silica content
it has high viscosity and a high explosive potential since its difficult for trapped gas to bubble out and escape
Why is drainage control sometimes an effective method of landslide control?
it reduces the amount of water in the hillslope materials
A _______________ species, such as the wolf or sea otter, has an effect on its ecological community disproportionate to its abundance.
keystone
The "dead zone" in the Gulf of Mexico results from
large amounts of nutrients, such as nitrogen and phosphorus, carried by the Mississippi River to the Gulf
How much of the Earth's water is stored as (non-saline) groundwater?
less than 1%
In what types of rock do most caves form?
limestone
The current flowing parallel to and just offshore of a beach is called
longshore current
How does earthquake magnitude differ from intensity?
magnitude reflects energy release, while intensity reflects the amount of shaking
The life story of most oceanic lithosphere is the same. It's created at ______________ and gets destroyed at _________________.
mid-ocean ridges; subduction zones (trenches)
How do soils become fertile?
mild weathering of parent material and addition of organic matter
Coastal marshes reduce flooding and coastal erosion. This impact is an example of
natural service functions of ecosystems
How a species "makes its living" is called its
niche
What are the two drinking water contaminates thought to pose an immediate health threat?
nitrate and fecal coliform bacteria
Mineral resources are
nonrenwable resources because new mineral deposits are forming too slowly to be of use on human time scales
Which of the following fossil fuels emits carbon dioxide, a greenhouse gas, when burned?
oil, coal, natural gas
What does the concept of environmental unity state?
one action leads to subsequent actions in linked systems
What are the requirements for a sediment to become a source rock for oil and natural gas?
organic matter must accumulate in a low-oxygen environment
We know there are water shortages in some parts of the world and we have to use our water resources more carefully. What is the root cause of the emerging global (fresh)water shortage?
over population
Why do manure spills into bodies of water result in fish kills?
oxygen in the water is consumed by the bacteria that breakdown the manure (concentrated organic matter)
Which of the following is NOT produced during a pyroclastic eruption?
pahoehoe basalt
________ are aggregates of soil particles that comprise soil structure.
peds
Point sources of pollution are confined to an area. An example is a leaking underground storage tank . Nonpoint sources of pollution are intermittent and not confined to an area. An example is the runoff from a field .
point sources, a leaking underground storage tank, nonpoint source, the runoff from a field
How are the impacts of natural hazards linked to population growth?
population growth concentrates people and resources, such that the impacts of an individual natural hazard can be greater
On what basis are Mercalli intensity values assigned to locations?
qualitative perceptions of and structural response to the shaking
Ocean-continent convergent plate boundaries
result in volcanic arcs built on the continent and mountain belts toward the interior of the continent
The smelting of sulfide ores
results in acid rain
Which of the following statements about stress and how rocks deform is CORRECT?
rocks shorten in response to compressive stresses and stretch in response to tensile stresses
Why are seacliffs so prone to erosion?
seacliffs are exposed to wave action, and they are also steep slopes, which can make them susceptible to landslides
How is the behavior of seismic waves traveling through the Earth used to characterize the Earth's interior?
seismic waves will reflect (bounce) or refract (bend) when they encounter a boundary between layers of different densities, seismic waves will speed up when they travel through rocks that are high density, and slow down when they travel through rocks that are less dense, S waves can't travel through liquid, so because they never travel all the way through the Earth, we can surmise that the outer core is liquid
The suspended load of most rivers consists mainly of
silt and clay
How is the development of sinkholes by collapse of cave roofs linked to water table levels?
sinkholes are more likely to form when water table levels drop due to drought or overpumping of groundwater
In a complex slide, such as the La Conchita slide in coastal California,
slides at the top of the slope may transform to flows at the base of the slope
Which of the following may INCREASE landslide hazards?
slip surfaces, like bedding planes or foliation planes, that are tilted in the downslope direction
Which of the following are environmental issues associated with the production and use of coal?
slurry impoundments, acid rain, and valley fill
The capability of a soil to provide nutrients needed for plant life is referred to as
soil fertility
How do engineers define soil?
solid Earth material that can be removed without blasting
Oil and natural gas originate in a fine-grained, organic-rich sedimentary rock referred to as a source rock . As these organics become hydrocarbons, they migrate upwards into porous, permeable rocks, such as sandstone or fractured limestone. This type of rock is called a reservoir rock . When upward migration is impeded by a barrier, known as a cap rock , the hydrocarbons can accumulate and become trapped.
source rock, resevoir rock, cap rock
A group of individuals capable of interbreeding is called a(n)
species
Which of the following statements about storm surge is CORRECT?
storm surge is highest on the side of the rotating storm that is blowing landward
Composite volcanoes are typically associated with what type of plate tectonic feature?
subduction zone
As an ecosystem evolves following disturbance, it follows the path of
succession
Viscosity of a magma is controlled by
temperature and silica content of the magma
The 1811-1812 New Madrid earthquakes were different from most California earthquakes because
the New Madrid earthquakes were centered in a plate interior
The biomagnification of mercury occurs as mercury moves through
the aquatic food chain
What is average residence time?
the average time that a human population can stay in an area before environmental conditions force them to move
The Mohorovicic discontinuity represents
the boundary between mantle and crust
Why does the withdrawal of fluids, such as water or oil, from the subsurface sometimes lead to subsidence?
the fluids provide partial support for the overlying rock mass, which collapses when the fluids are removed
Why is the geologic history of a volcano important in hazard prediction?
the geologic history reveals the frequency and style of eruptions
Why is cyanide heap leaching used to extract gold from some deposits?
the gold concentration is too low to be extracted using traditional methods
Which of the following statements is CORRECT?
the largest use of freshwater in the United States is for thermoelectric power generation
How does the lithosphere differ from the asthenosphere?
the lithosphere is stronger than the asthenosphere
Why do some faults "creep" with slow, constant movement and others are "stuck" and aren't moving?
the ones that are slowly creeping are lubricated by either fluids or slippery rocks, the ones that aren't moving are stuck together by friction
Darcy's Law allows geologists to calculate
the rate of discharge of an aquifer
Why does the damming of rivers sometime contribute to coastal erosion?
the supply of new sand to replenish beaches is cut off
The movement of the Pacific plate over a stationary mantle plume has produced volcanoes that make up the Hawaiian Islands (shown below). If the Pacific plate is moving to the northwest, what features should we expect to see in the hot spot track that is the Hawaiian Island chain?
the volcanoes should get progressively older towards the northwest end of the chain
Which of the following statements about the Ogallala aquifer is CORRECT?
the water table has dropped due to withdrawals for irrigation, domestic, and municipal use
When waves approach the shore and enter shallow water
the waves slow down and the wave height increases
What is one reason that ash fall is such a significant hazard?
the weight of the ash can cause structural damage to buildings
Which of the following statements about scientific theories and laws is correct?
theories are based on a body of data that have been repeatedly confirmed by observations or experiments
Water discharged from power plants creates what kind of pollution?
thermal pollution
How did mountain ranges like the Himalayas, Alps, and Appalachians form?
they are all examples of mountains that formed along continent-continent convergent plate boundaries
What adverse effect do groins, breakwaters, and jetties have on coastal erosion?
they block the transport of sand and starve downdrift areas of sand
Sulfide minerals are potential environmental hazards because
they can combine with oxygen and water to form sulfuric acid
What information would you need in order to prepare a landslide hazard map?
topography (steepness of slopes), the kinds of rocks or Earth materials present, inventory of past landslides
As velocity and discharge of stream increase, so does capacity.
true
China is the world's largest consumer of total energy, but the United States is the world's largest consumer of oil.
true
Erosion or removal of material from the base of a slope may increase landslide hazards.
true
Impact of urbanization on soil erosion is primarily a problem during the construction phase.
true
Intrusive igneous rocks consist of slowly cooled magma.
true
New oceanic lithosphere is generated at mid-ocean ridges.
true
P-waves travel faster than surface waves.
true
How can you estimate the time it takes for a population to double in size?
use the formula D = 70/G, where D = time and G = growth rate
As water infiltrates the ground it travels through the earth material above the water table known as the vadose zone . The area beneath the water table where all the pore spaces are filled with water is called the zone of saturation .
vadose zone, zone of saturation
Most water pollution associated with mining operations has to do with
water passing through mine wastes
If water is so abundant on Earth, why are water resources such a big concern?
water resources are not necessarily where humans need them and when they need them
Nutrient levels in wastewater can be reduced by cycling wastewater through
wetlands
Why is it necessary to keep cooling water flowing through a nuclear reactor core?
without the water, heat will build up in the reactor core, which may lead to a meltdown
Identify THREE environmental concerns related to coal production and use.
Air pollution from coal fires, Water pollution from coal sludge left over from coal processing, Permanant marks on the land surface from heavy equipment.
Aside from recycling, the only viable source of aluminum is from which mineral?
Bauxite