Geology 101 Midterm

Which soil horizon is known as topsoil?

A

When the water table intersects the ground, it will discharge as

A spring

Environmental geology

C (is the study of human interactions with the Earth environment, hazards, and resources) and D (is applied geology) are correct.

Why does the damming of rivers sometime contribute to coastal erosion?

Correct! the supply of new sand to replenish beaches is cut off

Which of the following would be considered a point source of pollution?

Discharge of industrial wastewater

Why are native trees more diverse in North America than in Europe?

European trees were trapped between the ice sheet and E-W trending mountain ranges

Which of the following does NOT tend to increase biodiversity in an ecosystem?

Extreme disturbance

An ecosystem involves only the living organisms in a region.

False

Cinder Cones form on oceanic plates above hotspots.

False

Desalination is a low-cost, low-energy alternative to conventional water resources.

False

Limestone is a detrital sedimentary rock.

False

Which of the following types of renewable energy displaces people and traps sediment so that beaches aren't replenished with sand?

Hydroelectric Power

If a stream channel is of constant width and depth, how must increased discharge be accommodated?

Increased velocity

An indigenous ecosystem is one that

Is not impacted by humans

The current flowing parallel to and just offshore of a beach is called

Longshore current

Why is human population growth considered an environmental problem?

More resources are needed, more waste is produced, creating greater amounts of disruption to the environment.

Coastal marshes reduce flooding and coastal erosion. This impact is an example of

Natural service functions of ecosystems

As an ecosystem evolves following disturbance, it follows the path of

Naturalization

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

_______ are aggregates of soil particles that comprise soil structure.

Peds

Darcy's Law allows geologists to calculate

Rate of discharge of an aquifer

The smelting of sulfide ores

Results in acid rain

How is the behavior of seismic waves traveling through the Earth used to characterize the Earth's interior?

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 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 seismic waves will reflect (bounce) or refract (bend) when they encounter a boundary between layers of different densities

How do seismologists know the outer core is liquid?

S-waves are absorbed upon arrival in the outer core

The suspended load of most rivers consists mainly of

Silt and clay

The capability of a soil to provide nutrients needed for plant life is referred to as

Soil fertility

Composite volcanoes are typically associated with what type of plate tectonic feature?

Subduction zone

The biomagnification of mercury occurs as mercury moves through

The aquatic food chain

is the boundary between the vadose zone and the saturated zone

The water table

Sulfide minerals are potential environmental hazards because

They can combine with oxygen and water to form sulfuric acid

The 1811-1812 New Madrid earthquakes were different from most California earthquakes because

They were centered in a plate interior

A concentration of minerals that can be legally mined at a profit at the current time is called a reserve.

True

Any shoreline construction causes change in the beach environment.

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. Correct!

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

Sinkholes often result from water table fluctuations.

True

Science

Uses observation, experiment, and calculations to explain natural phenomenon

Biotechnology can help reduce the environmental impacts of mining through

Using plants to revegetate mine waste piles and constructing wetlands to treat contaminated water

Which of the following does not influence wave size?

Wind temp

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

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

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

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 tsunami may occur when _____.

an earthquake occurs on or near the ocean floor. an volcano erupts underwater. an underwater landslide occurs.

Vegetation influences slope stability in part by

anchoring soils and other materials on the slope

Synthetic organic chemicals like PCBs, dioxins, MTBE, etc.

are toxic, accumulate in the food chain, dont breakdown in the environmenet

A lahar is produced when

ash and other pyroclastic ejecta become saturated with water

What environmental impact does the production of shale gas and tar sands have in common?

both generate contaminated waste water

What type of river channel is characterized by multiple channels and gravel bars?

braided

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

The total load of sediment that a river carries in a given period of time is called

capacity

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 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.

erodability

What phase of mining generally causes the least environmental degradation?

exploration and testing

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

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 reaccurance 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

Why might the emission of radon gas be useful in predicting earthquakes?

fracturing of the rocks allows radon to move more readily

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

Why was Alfred Wegener's hypothesis of continental drift not taken seriously by most geologists?

his mechanism for movement of the continents was faulty

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, magnets in wind turbines, and computer screens

Sea otter reintroduction in Alaska has led to

increase in kelp forests

Hydraulic conductivity in soils increases with

increase particle size

As a tsunami approaches land, the height of a tsunami wave ____.

increases primarily because the water depth and velocity decreases.

The Moment Magnitude of an earthquake

is a measure of the energy released in the earthquake requires knowledge of the amount of slip on the fault, the length and depth of the fault rupture, and the strength of the rocks involved in order to calculate it

The sludge from sewage treatment plants

is used as fertilizer because it contains nitrogen and phosphorus

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

What is sustainability?

meeting the needs of the present generation without compromising the ability of future generations to meet their needs

Regional metamorphism involves ______________, and contact metamorphism involves _________________.

metamorphism of rocks over a large geographic area at convergent plate boundaries; local heating of rocks around an intrusion of magma

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

Seismic activity serves as a tool of volcanic forecasting because

moving magma causes a type of earthquake called a harmonic tremor

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

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

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

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

The shrink-swell potential of a soil is dependent upon

proportion of clay in the soil

On what basis are Mercalli intensity values assigned to locations?

qualitative perceptions of and structural response to the shaking

Which of the following statements about stress and how rocks deform is CORRECT?

rocks shorten in response to compressive stress and stretch in response to tensile stress

Which of the following may INCREASE landslide hazards?

slip surfaces, like bedding planes or foliation planes, that are tilted in the downslope direction

How do slumps and translational slides differ?

slumps are rotational, while translational slides are planar

Which of the following are environmental issues associated with the production and use of coal?

slurry impoundments, acid rain, and valley fill

How do engineers define soil?

solid Earth material that can be removed without blasting

Why are most active volcanoes associated with plate tectonic boundaries?

spreading or sinking plates interact at plate boundaries with other materials to produce magma

Which of the following would be the MOST STABLE slopes?

steep, forested slopes with good drainage

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

Viscosity of a magma is controlled by

temperature and silica content of the magma

What is average residence time?

the average time required for the total stock of a material to be cycled through a system

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 about the lithosphere and asthenosphere is CORRECT?

the lithosphere is composed of crust and the uppermost mantle and forms rigid plates

The safety factor for landslides is

the ratio of resisting to driving forces

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

What is one reason that ash fall is such a significant hazard?

the weight of the ash can cause structural damage to buildings

How do magnetic stripes on the ocean floor serve as evidence for seafloor spreading?

their symmetry on either side of the mid-ocean ridge shows that new crust is created, then split

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

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

Which of the following is NOT a criteria by which minerals are defined?

they can be solid, liquid, or gas

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

Transform plate boundaries are marked by

two plates sliding relative to one another

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

Which of the following is not a mineral?

volcanic glass

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

Why are headlands more susceptible to erosion than bays?

waves converge on the headlands due to wave refraction

Nutrient levels in wastewater can be reduced by cycling wastewater through

wetlands

Surface waves (like Love or Rayleigh waves) are produced

when P- and S-waves reach the surface, causing the ground to shake and roll

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

can be any Earth material with high porosity and high permeability

Aquifers

Shield volcanoes have gently-sloping sides because they are dominated by eruptions of runny

Basalt

Aside from recycling, the only viable source of aluminum is from which mineral?

Bauxite

In the next few decades, water resources in the Colorado River Basin are expected to

Be stressed even further due to population growth