Geo 101

If I say a flood has a recurrence interval of 100 years (a 100 year flood), what does that mean in terms of how frequently that magnitude flood can occur? What is the formula that is used to estimate the recurrence interval for a particular magnitude flood?

A 100 year recurrence interval means that a flood equal to or greater than a given magnitude will occur about every 100 years. It also means that there is a 1% chance a flood of this magnitude will happen each year. R=(n+1)/m

Which soil horizon is known as topsoil?

A Horizon

Why did Mount St. Helens erupt in a lateral blast on May 18, 1980? Pick the most correct answer.

A bulge formed on the flank of the mountain. An earthquake triggered a landslide that that dislodged the bulge, triggering a lateral eruption.

What is a seismic gap?

An area along an active fault that has not generated an earthquake recently so it is likely to produce a large earthquake in the future.

You are relocating to a seismically active area and are looking to buy a house. Should you buy a house built on bedrock or one built on soft sediments like clay-rich soils? Why?

Bedrock because it will experience less ground shaking than soft sediments like clay-rich soils.

Which of the following drawings shows detrital sediment that was likely transported for a long time and deposited far from the source? -A -B -C

C

Put these detrital sediments/sedimentary rocks in order of increasing particle size and increasing energy of the environment in which they were deposited. Put the sediment/rock with the smallest particle size and lowest energy environment first, and the sediment/rock with the largest particle size and highest energy environment last.

CLAY/SHALE, SILT/SILTSTONE, SAND/SANDSTONE, PEBBLES/CONGLOMERATE

At convergent plate boundaries, the subducting oceanic plate grinds along the base of the overriding plate, generating large [F].

Earthquakes

Why are native trees more diverse in North America than in Europe? -the larger ice sheets in North America caused more species to go extinct -North American trees expanded into mountain ranges during glaciations - European trees were trapped between the ice sheet and E-W trending mountain ranges -North American trees are all of tropical origin

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

Land subsidence in the San Joaquin Valley of California resulted mostly from oil extraction. (T/F)

False

Silicate minerals are the most common minerals in the outer core. (T/F)

False

The Hawaiian Islands are a volcanic arc atop an oceanic subduction zone. (T/F)

False

The magnitude of an earthquake is a function of how far away you are from the earthquake. (T/F)

False

When detrital sediments are transported for long periods of time, the proportion of feldspar decreases while the proportion of quartz increases. Why?

Feldspar chemically weathers to small clay particles during transport. The quartz particles are more resistant to weathering and can be transported longer and farther.

Do large pyroclastic eruptions cause short-term global warming or global cooling? Why?

Global cooling, because the particles and gases ejected into the atmosphere create aerosols that block solar radiation.

What environmental problem is associated with the mining and processing of sulfide ores?

Groundwater and surface water infiltrate the mines and combine with sulfide minerals forming acidic water with elevated concentrations of dissolved metals. The acidic water drains from the mine and pollutes surrounding streams and rivers

Based upon lessons learned from recent flood events (Mississippi and Missouri River), what are problems levees create rather than solve?

Levees can provide a false sense of security. Reduces the creation of floodplain surfaces and wetlands. Floodplains and wetlands help moderate the impacts of flooding events. More damage when levees fail catastrophically.

Oceanic lithosphere is created at [D] and returns to the mantle at [E].

Mid-Ocean Ridges, Subduction Zones

( ) crust is denser and thicker then ( ) crust

Oceanic, Continental

Which seismic wave travels the fastest?

P-waves

Table sugar, also known as sucrose (like the kind in rock candy), is NOT a mineral because... ....

Sugar is derived from plants (sugar cane or sugar beets) so it is an organic compound. Minerals are inorganic.

Any shoreline construction causes change in the beach environment. (T/F)

True

As velocity and discharge of stream increase, so does capacity. (T/F)

True

Erosion or removal of material from the base of a slope may increase landslide hazards. (T/F)

True

Impact of urbanization on soil erosion is primarily a problem during the construction phase. (T/F)

True

New oceanic lithosphere is generated at mid-ocean ridges. (T/F)

True

P-waves travel faster than surface waves. (T/F)

True

Sinkholes often result from water table fluctuations. (T/F)

True

Why can monitoring seismic activity help forecast volcanic activity? Give a complete explanation.

Volcanic eruptions are almost always preceded by increased seismic activity. Increasing seismic activity (harmonic tremors) tell us the magma is moving close to the surface within the plumbing of the volcano and an increase in this seismic activity often indicates that the volcano is preparing to erupt.

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 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 -a time when the rock sequence was below sea level - a period of igneous intrusion -an example of the principle of superposition

a gap in the geologic record

What is a theory? -a possible explanation for a set of observations -a hypothesis that has withstood extensive testing -a set of ideas that unifies a field of inquiry - an idea that is based only on logical thought

a hypothesis that has withstood extensive testing

Why is it possible for an ecosystem adapted to cool temperatures (algific talus slopes), to thrive in the warm summer climate of Iowa? -these slopes never get any sunlight and are always in the shade - large plants block the sunlight from small plants, keeping them cool -air chilled by flowing through fractured and partially dissolved limestone and dolomite bedrock creates a microclimate with cooler temperatures - it is always cooler next to any outcrop of bedrock, so wherever there are rock exposures at the surface, the temperatures will be cooler

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 -a biosphere -a habitat -an ecological community -a geological community

an ecological community

Why is human population growth considered an environmental problem? -there is insufficient oxygen production on Earth for more than 10 billion people - as the population increases, more resources are needed and more waste is produced, causing greater amounts of disruption to the environment - there isn't enough land to feed any more people than what we have now -all of the above

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

The ( ) is the weak layer in the mantle that allows tectonic plates to slip, collide and separate

asthenosphere

In an ionic bond -chains or sheets of atoms are held together by weak forces -atoms are joined by negatively or positively charged ions - electrons are shared between all atoms in a solid mass -electrons are shared between a limited number of atoms

atoms are joined by negatively or positively charged ions

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

basalt

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

Clay minerals are used in the manufactors of _________. (pick 3)

bricks, ceramics, landfill liners

Faults are a result of [a] deformation, and folds are a result of [b] deformation.

brittle, ductile

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

An advantage of the Universal Soil Loss Equation is that it

can evaluate the potential impact of conservation practices that control erosion

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

capacity

Limestone is prone to chemical weathering where the rock can dissolve to form caves because it consists of a mineral from the -oxide group - silicate group - carbonate group -native element group

carbonate group

The maximum number of people Earth can hold without causing prohibitive environmental degradation is called -uniformitarianism - carrying capacity -faunal succession -the precautionary principle

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

Why do composite volcanoes consist of alternating lava and pyroclastic layers?

composite cones are created by a mixture of explosive activity and lava flows

What type of volcano is associated with volcanic arcs built over subduction zones?

composite volcanoes

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

Detrital sedimentary rocks differ from chemical sedimentary rocks in that -detrital sedimentary rocks accumulate in depositional basins, while chemical sedimentary rocks do not -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 - chemical sedimentary rocks are composed of chemical elements, while detrital rocks are not -chemical sedimentary rocks only accumulate in the ocean and detrital sedimentary rocks only accumulate on land

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

transform plate boundary

edges of plates slide past each other

In a covalent bond, -chains or sheets of atoms are held together by weak forces -atoms are joined by electrical charges -electrons are shared between all atoms in a solid mass - electrons are shared between a limited number of atoms

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

Which of the following does NOT tend to increase biodiversity in an ecosystem? -evolution -diverse habitats -extreme disturbance -relatively constant environmental factors

extreme disturbance

Why is flood hazard mapping considered an important step in floodplain management?

flood hazard mapping guides appropriate development in the floodplain

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

The is the location at depth where the rocks rupture and release the energy to produce an earthquake. The is the point on the earth's surface that is directly above the location of the rupture.

focus, epicenter

Some metamorphic rocks are potential environmental hazards because -foliation planes can be planes of weakness in the rock -the fluids that metamorphose the rocks can leave behind dangerous chemicals -they are composed of unstable elements - the crystals do not interlock as in igneous rocks

foliation planes can be planes of weakness in the rock

Strong bedrock, like granite, influences the formation of what types of hillslopes?

free cliff face with talus at the base

The mineral quartz can be used in the manufacture of _______ . (pick 3)

glass, jewelry, abrasives

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

Why was Alfred Wegener's hypothesis of continental drift not taken seriously by most geologists? -his evidence for former joining of the continents was faulty -because it was and is known that continents do not move - his mechanism for movement of the continents was faulty -he was not a well-respected scientist

his mechanism for movement of the continents was faulty

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 -extinction of sea urchins -increase in kelp forests -decrease in kelp forests -ecosystem degradation

increase in kelp forests

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 heavily impacted by humans -is not substantially impacted by humans -is reconstructed by humans - includes native human beings

is not substantially impacted by humans

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 - indigenous -exotic -invasive

keystone

Off-road vehicle use contributes to soil problems by

loosening soil and changing the hydrology of a site

How does earthquake magnitude differ from intensity?

magnitude reflects energy release, while intensity reflects the amount of shaking

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

Coastal marshes reduce flooding and coastal erosion. This impact is an example of -ecosystem restoration - ecological succession -environmental stewardship - natural service functions of ecosystems

natural service functions of ecosystems

How a species "makes its living" is called -its habitat - niche -biota -ecology

niche

Why do the continents contain significantly older crust than the oceans? -continental crust is not being made anymore, but new oceanic crust is made all the time -continental crust is resistant to erosion -oceanic crust is eventually destroyed by sinking into the mantle at subduction zones, but thick continental crust does not subduct, resulting in the preservation of very old continental crust -continental crust formed early in Earth's history and oceanic crust formed late in Earth's history

oceanic crust is eventually destroyed by sinking into the mantle at subduction zones, but thick continental crust does not subduct, resulting in the preservation of very old continental crust

What does the concept of environmental unity state? -one action leads to subsequent actions in linked systems -all humans live on Gaia, and therefore we are subject to the same environment - all people on Earth agree on the nature of and solutions to environmental problems - all systems are related to one another

one action leads to subsequent actions in linked systems

Soil taxonomy is a classification system based on

physical and chemical properties of the soil

convergent plate boundary

plates are colliding with each other, oceanic plates subduct under continental plates

divergent plate boundary

plates are moving away from each other at mid ocean ridges

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 - population growth weakens societal defenses against natural hazards -natural hazards strongly influence population growth -population growth changes the frequency of natural hazards

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

Which of the following statements about stress and how rocks deform is CORRECT? -permanent deformation is brittle and elastic deformation is ductile -joints are fractures that have experienced movement -rocks shorten in response to compressive stresses and stretch in response to tensile stresses -folds like anticlines and synclines can form from tensile and shear stresses, but not compressive stresses

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

The portion of rainfall that flows off the land and directly into a river is called

runoff

How does urbanization affect runoff and flooding?

runoff increases and the time between the precipitation event and water rise in local streams decreases

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

The suspended load of most rivers consists mainly of

silt and clay

What types of Earth materials are most likely to amplify seismic waves and undergo liquefaction?

soft sandy soils and clay-rich soils

How do engineers define soil?

solid Earth material that can be removed without blasting

A group of individuals capable of interbreeding is called a(n) -ecosystem -species -biota -ecological community

species

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

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

subduction zone

Which type of seismic wave does the most damage?

surface waves

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 -the average time for a system to run out of energy -the average time that a human population can stay in an area before environmental conditions force them to move -the average time for an open system to convert to a closed system

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

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

Which of the following statements about the May 18, 1980 eruption of Mt. St. Helens is CORRECT?

the ground swelling and bulge that appeared on the north side of Mt. St. Helens was a good clue that magma was accumulating just below the surface

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 asthenosphere rides on top of the lithosphere -the lithosphere is hot and plastic - the asthenosphere is located between th

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

How does the lithosphere differ from the asthenosphere? -the lithosphere is stronger than the asthenosphere -the asthenosphere is stronger than the lithosphere -the asthenosphere is part of the core, while the lithosphere is part of the mantle -the asthenosphere is less dense than the lithosphere

the lithosphere is stronger than the asthenosphere

The concept that one action leads to other actions in a linked system is referred to as -the principle of uniformitarianism -the principle of environmental unity -the principle of carrying capacity -the principal of exponential growth

the principle of environmental unity

The shrink-swell potential of a soil is dependent upon

the proportion of clay in the soil

The safety factor for landslides is

the ratio of resisting to driving forces

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 youngest, most active volcanoes should be at the northwest end of the chain -the volcanoes should get progressively older towards the northwest end of the chain - all of the volcanoes in the chain should be currently active - none of the above

the volcanoes should get progressively older towards the northwest end of the chain

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 -their patterns show that the Earth's magnetic field reverses every few hundred years, on average -they show that island arc volcanism creates new oceanic crust at the mid-ocean ridges -their symmetry on either side of mid-ocean ridges shows that transform boundaries are sliding boundaries

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 turn into laws - laws explain why the world works the way it does -once developed, theories cannot change - theories are based on a body of data that have been repeatedly confirmed by observations or experiments

theories are based on a body of data that have been repeatedly confirmed by observations or experiments

How did mountain ranges like the Himalayas, Alps, and Appalachians form? -they all formed in collision zones along large bends in transform plate boundaries - they all grew over stationary mantle plumes -they all formed at divergent plate boundaries -they are all examples of mountains that formed along continent-continent convergent plate boundaries

they are all examples of mountains that formed along continent-continent convergent plate boundaries

What is a drawback of seawalls?

they bounce wave energy back across the beach and cause erosion

A transform plate boundary involves -two plates sliding past each other, such as the North American plate and the Pacific plate sliding past each other along the San Andreas Fault - two plates moving away from each other - the collision of two continents - a younger oceanic plate subducting under an older oceanic plate

two plates sliding past each other, such as the North American plate and the Pacific plate sliding past each other along the San Andreas Fault

How can you estimate the time it takes for a population to double in size? -use the formula T = S/F, where T = time, S = total size of the stock, and F = average rate of transfer - use the principle of environmental unity -use the formula D = 70/G, where D = time and G = growth rate -use the precautionary principle

use the formula D = 70/G, where D = time and G = growth rate

Science -seeks information that fits one's beliefs -is a collection of facts that proves ideas -uses observation, experiment, and calculations to explain natural phenomena -cannot be used to make accurate predictions

uses observation, experiment, and calculations to explain natural phenomena

Urbanization influences soil erosion processes primarily because of

vegetation removal and soil disturbance at construction sites

Which of the following is not a mineral? -volcanic glass - ice -quartz -plagioclase feldspar

volcanic glass

Why are headlands more susceptible to erosion than bays?

waves converge on the headlands due to wave refraction

Surface waves (like Love or Rayleigh waves) are produced

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

Which of the following does not influence wave size?

wind temperature

A tsunami may occur when _____.

All of the above have the potential to cause a tsunami.

Why do some faults "creep" with slow, constant movement? What keeps other faults from constantly moving?

"Creeping" faults are lubricated by either fluids or slippery rocks. Faults that aren't moving are stuck together by friction.