Combo with "EAR 106 Exam 3" and 3 others
In this 800,000-year climate record from Antarctica, we see that carbon dioxide concentrations have consistently ranged between ___ parts per million while the climate system oscillated back and forth between glacial and interglacial periods
180 and 280
Because human activity has pushed carbon dioxide levels up to ___ parts per million by 2012, a level far above Earth's normal operating range, scientists fear this could destabilize the climate system and cause ___ rather than ___ climate change
395; abrupt; gradual
About how many years old is the Earth as shown by science?
4.6 billion
crust
Earth's outermost layer consisting primarily of silicate-rich rocks whose density is lower than those in the underlying mantle
artificial levees
Earthen mounds or concrete panels constructed along river banks by humans for the purpose of keeping a river from overflowing its banks and inundating its floodplain; those made of concrete are often called floodwalls
The detailed 2,000-year climate record (red) from Greenland includes the ___, which coincides with the expansion of human settlements in Europe and Greenland. The ___ followed, causing the collapse of Greenland colonies and bringing famine to Europe
Medieval Warm Period; Little Ice Age
Which of the following volcanoes in the U.S. is most notably for having a history of massive mudflows, which today threatens large numbers of people?
Mt. Rainier, Washington
Milankovitch cycles
Refers to the cyclical changes in solar heating of the Earth caused by periodic changes in the way the planet orbits the Sun; when the orbital parameters (eccentricity, axial tilt, and precession) reinforce each other, the resulting change in heat balance can trigger an overall cooling or warming trend
One concern is that the loss of sea ice may soon pass ___, beyond which the ice would not return in the forseeable future, thereby ___ the rate of global warming
a critical threshold; speeding up
Which of the following are effective ways of reducing the effects of flooding?
a. all (b. artificial levees; c. channelization; d. erosion controls; e. wetlands restoration)
viscosity
ability of a fluid to resist flow that is caused by internal friction within the fluid; in magma, greater silica content and cooler temperatures result in greater internal friction, hence increased viscosity
infiltration capacity
ability of the land surface to absorb water. Water that is unable to infiltrate is generally forced to move downslope as overland flow
sustainability
ability to maintain a system or process for an indefinite period of time; sustainable society is one that lives within the Earth system's capacity to provide resources such that they remain available for future generations
Which of the following best explains the effect of greenhouse gases on Earth's atmosphere?
absorb some of the energy Earth radiates out into space
Greenhouse gases ___ some of the outgoing radiation, which is then transferred to the atmosphere as ___ energy
absorb; thermal
Because of the spinning motion, the cloud takes the shape of a disk and young planets begin forming by ___, the process where particles collide due to gravitational attraction
accretion
volcano
accumulation of extrusive materials around a vent through which lava, gas, or pyroclastics are ejected into the surface environment
With respect to modeling Earth's climate system, which of the following best describes global circulation models (GCMs)?
accurately stimulate the past climate and are used to project the future climate
absolute age
actual age of rocks in terms of years
rock
aggregate or assemblage of one or more types of minerals
Which of the following factors affect the amount of damage caused by an earthquake?
all (a. natural vibration frequency and resonance; c. building construction design; d. number of secondary hazards; e. amount of ground shaking)
Which of the following statements regarding subduction zones is true?
all (a. subduction zones are capable of generating extremely powerful earthquakes; b. subduction zone earthquakes are associated with compressional stress; c. subduction zone earthquakes are associated with convergent plate boundaries; e. the Cascadia fault is part of a subduction zone located in the northwestern United States
Ice core data have revealed which of the following?
all (a. there's a strong correlation between atmospheric carbon dioxide and temperature' c. current carbon dioxide concentrations are far outside of Earth's recent operating range; d. Earth's climate has been remarkably stable for the past 10,000 years; e. Earth's climate shows a history of abrupt and rapid changes in temperature
Which of the following statements is true regarding earthquakes?
all (a. they represent the sudden release of energy that has accumulated within rocks; b. they represent the vibrations that occur as seismic waves travel through rocks; c. they result rocks being offset or displaced along faults; e. they form when brittle rocks exceed their elastic limit
Which of the following is a secondary hazard associated w/ earthquakes?
all (a. tsunamis; b. landslides and open fissures; c. liquefaction; e. fires)
Which of the following is a common triggering mechanism that causes slopes to fail suddenly?
all (b. earthquakes; c. heavy rainfall events; d. wildfires; e. over-steepening a slope)
Which of the following statements regarding carbon dioxide and the greenhouse effect is true?
all (b. global warming from burning fossil fuels was predicted in the 1800s; c. link between CO2 and the greenhouse effect was proven in the 1800s; d. CO2 concentration in the atmosphere is relatively low; e. without CO2, the average global temperature would be below freezing)
Which of the following do climatologists predict will occur as the Earth continues to warm?
all (b. higher evaporation rates, c. more frequent heavy rain and snow events, d. more frequent droughts, e. atmosphere will hold more water vapor)
Which of the following assumptions are inherent in the concept of habitable zones?
all life-forms require liquid water
chemical weathering
any chemical process that causes minerals within rocks to decompose into simpler compounds and individual ions
earth resources
any natural resource that comes from the solid earth; examples: water, soil, mineral, and energy resources
back swamps
areas of the floodplain that are poorly drained and can remain wet for extended periods of time; drainage is inhibited by natural levees, high water tables, and fine-grained sediment beneath the swamps
Therefore, the greater the difference in ___ between P- and S- waves the ___ a station is to the epicenter
arrival time; farther away
Stability of earth materials on slopes depends on the balance of gravitational and frictional forces. Which of the following does not have a measurable effect on the balance between gravity and friction?
atmosphere air pressure
Which of the following statements with respect to Earths climate is not true?
atmospheric carbon dioxide levels are currently well within Earth's recent operating range
The ability of certain ___ to trap heat and warm the planet is known as the greenhouse effect
atmospheric gases
The use of engineering controls is one of the two basic methods for minimizing mass wasting hazards. Which of the following is the other basic approach to minimize mass wasting hazards?
avoid building in hazard zones
extremophile bacteria
bacteria that thrive under extreme conditions, such as ancient Antarctic ice, superhot vents on the seafloor, and rocks located deep underground; Earth's complex plant and animal life is generally believed to have evolved from extremophile bacteria
lava flow
body of lava that flows out onto the land surface and eventually cools and solidifies into an igneous rock
historical geology
branch of geology that examines Earth's past by unraveling the information held in rocks
environmental geology
branch of geology that examines the interaction between humans and the geologic environment; common issues: resources, hazards, and pollution
Suppose that engineers are unable to keep earth materials from coming down onto a highway. In this case, which of the following would be the most economical and effective technique for reducing the hazard?
build a protective structure
Which of the following engineering controls would be best suited to strengthen a slope that has been over-steepened by cutting into the hillside during highway construction?
build a retaining wall
Imagine a section of highway with a large outcrop of fractured rock that poses a serious rockfall hazard. Which of the following engineering controls would be the best choice for minimizing the chance of large rocks falling onto the roadway?
building a retaining wall
How was the geologic time scale developed?
by correlating exposed rock sections from around the world
calcite
calcium carbonate mineral that is a major constituent in the group of rocks called limestone, and used as the raw material for making cement and concrete
Which of the following terms is used to describe a large circular depression that forms after an eruption when a magma chamber becomes empty and collapses in on itself?
caldera
mid-oceanic ridges
chain of submarine mountains, circling nearly the entire globe, where rising magma and seafloor spreading produce new oceanic crust
environmental risk
chance that some natural process or event will produce negative consequences for an individual, or society as a whole; risk is characterized in terms of probability and consequences
crater
circular depression around a volcanic vent that forms during an eruption as pyroclastic material is ejected into the air
caldera
circular depression that forms after a volcanic eruption when rocks begin collapsing or subsiding into the now empty magma chamber; some geologists also refer to large craters that form during explosive eruptions as calderas
sinkholes
circular depressions created by the collapse of solution cavities in limestone rock. In areas with large numbers of sinkholes, the landscape takes on a pitted or cratered appearance referred to as <i>karst</i> terrain
convection cells
circular motion of heat and matter within the Earth that is driven by temperature-induced changes in the density of material
As illustrated in (A), the ___ of a region is the statistical variation of daily ___ events, where the number of days with cool weather ___ the days with warm weather. Global warming is expected to cause a shift in ___ worldwide, resulting in more hot ___ events and record highs compared to today
climate; weather; roughly equals; climate; weather
coal
combustible sedimentary rock that forms when accumulated plant material becomes deeply buried under new sediment. The corresponding higher levels of heat and pressure drive off water and other volatile compounds, leaving behind a solid that is highly concentrated in carbon
multiple working hypotheses
common in the early stages of an investigation where researchers develop more than one plausible hypothesis for a given set of data; number of hypotheses normally decreases over time as new data show one or more hypotheses to be false
basalt
common type of extrusive igneous rock found in oceanic crust that is rich in plagioclase feldspar and ferromagnesian minerals
granite
common type of intrusive igneous rock found in continental crust that contains relatively few ferromagnesian minerals, but is rich in quartz and potassium feldspar
slump
complex form of mass wasting involving unconsolidated material where sliding takes places near the top of the slump, transitioning to a flowing mechanism toward the bottom
stabilization triangle
concept illustrating the amount that carbon dioxide emissions would need to be reduced in order to keep future emissions at a steady level; emission reductions are achieved through stabilization wedges, which represent individual techniques, such as increased use of wind power and higher fuel mileage
climate threshold
concept in which some component of Earth's climate system is pushed beyond a critical point, causing the entire system to suddenly change; positive feedback mechanisms would then amplify the change
Earth systems science
concept where the Earth is viewed as a dynamic, constantly changing system composed of four major components: atmosphere, hydrosphere, biosphere, and geosphere
talus pile
cone-shaped deposit of rocks that accumulates at the base of exposed rock bodies due to mass wasting processes
composite cone
cone-shaped volcano with steep slopes that consists of alternating layers of pyroclastic material and lava flows; also called a stratovolcano
Which of the following human activities commonly causes the over-steepening of slopes, which then leads to mass wasting?
construction of roads
The Himalaya Mountains are an example of which of the following types of plate boundaries?
continental-continental convergence
Which of the following processes drives the movement of tectonic plates?
convection cells in the mantle
Which of the following statements best describes extrusive igneous rocks?
cool on the surface and have a fine-grained texture (small mineral crystals)
As the amount of Arctic sea ice continues to shrink, it ___ the amount of reflected sunlight, which ___ solar heating and causes the Arctic Ocean to become warmer
decreases; increases
Because volcanic ash is composed of rocky material, it is also relatively ___
dense
nebular hypothesis
describes how all solar system objects originally formed from a rotating cloud of dust and gas called a nebula
Because, Earth's existing ___ are expected to become larger, humans will likely have to move to what are now ___ in search of habitable living space
deserts; polar regions
Which of the following best explains why rocks can be used to interpret the geologic past?
different types of rocks form in different types of environments
Physical weathering causes rocks to ____ by some mechanical process, whereas chemical weathering refers to ___ via chemical reactions
disintegrate into smaller particles; the decomposition of minerals
At what type of plate boundary would you expect to find new oceanic crust being created?
divergent
What best explains the problem with using sediment layers to determine past climatic conditions?
do not provide details on year-to-year variations
What best describes the basic role of streams in the Earth system?
drain water from the landscape and transport sediment
A warmer world should also bring a greater number of record highs, which will increase the potential for ___ conditions. These conditions will worsen in some areas because spring rains are occurring ___, which will ___ the amount of time soils are exposed to dry, summer conditions
drought; earlier; increase
pyroclastic flow
dry avalanche consisting of hot rock fragments, ash, and superheated gas that rushes down the side of a volcano at great speed
What best describes a pyroclastic flow?
dry avalanche of hot material
heat balance
dynamic relationship where Earth naturally attempts to balance the amount of heat energy it radiates into space with the amount of energy it receives from the Sun. When the heat balance is disrupted, Earth either gains or loses heat until a new equilibrium can be established
liquefaction
earthquake phenomenon that occurs when the ground shaking causes sand-rich layers of sediment to behave as fluid
intraplate earthquakes
earthquakes that occur far from a plate boundary or active mountain belt
subduction zone earthquakes
earthquakes that occur when an oceanic plate is overridden by another plate, generating some of the more powerful earthquakes on record
magmatic earthquakes
earthquakes that result from the strain that accumulates as rising magma forces its way through crustal rocks
There are several long-term changes in Earth's orbit that affect how heat from the Sun is distributed over the planet. Which of the following describes how the orbit changes from being elliptical to more circular?
eccentricity
retention basins
engineering structure designed to reduce flooding by temporarily storing excess surface water before it can reach a stream channel
retaining wall
engineering structure designed to strengthen an oversteepened slope; commonly used when a flat surface is needed in sloping terrain for a roadway, building, or parking lot
rock bolts
engineering technique that utilizes a steel rod and anchoring system to prevent fractured blocks of rock from falling onto highways and rail lines. Also used for stabilizing walls and ceilings in tunnels and underground mines
tragedy of the commons
environmental concept in which the self-interest of individuals results in the destruction of a common or shared resource
creep
exceptionally slow type of mass wasting process where repeated expansion and contraction causes unconsolidated materials to move downslope
elastic rebound theory
explains how earthquakes originate when a rock body deforms and accumulates strain such that it reaches its elastic limit, at which point the rock suddenly fails and releases its stored energy
Which trend best described human population growth?
exponential
Earthquakes and volcanic eruptions are randomly distributed on the Earth
false
Locating the distance from a seismograph station to an earthquake epicenter is based on the fact that P-waves travel ___ than S-waves and always arrive ___ at a given seismograph station
faster; first
Because human activity has been releasing carbon dioxide into the atmosphere ___ than the rate it is being removed by natural processes, atmospheric temperatures are expected to keep ___ for many years even if we stopped all emissions today
faster; increasing
paleoclimatology
field of study that examines Earth's history of climate change using a variety of tools, including sediment, hydrogen and oxygen isotopes, tree rings, and glacial ice
volcanic ash
fine pyroclastic fragments that are ejected from a volcano, then fall from the sky downwind of the volcano, sometimes traveling hundreds or even thousands of miles
slate
fine-grained and highly foliated type of metamorphic rock that forms when clay minerals in a shale are transformed into platy minerals of the mica family
natural floodplain
flat portion of a river valley underlain by sediment, which has been deposited over time as the river periodically overflows its banks
channelization
flood control technique that involves straightening and deepening a stream channel so that its discharge capacity is increased, thereby reducing the probability that water will overflow the banks
flash floods
flood in which a stream rises and falls rapidly; also known as upstream floods since small streams in the upper reaches of a drainage system tend to quickly overflow their banks during heavy rain events
tension
force that pulls on a rock body from opposite directions, causing it to become stretched or lengthened
compression
force that pushes on a rock body from opposite directions, causing it to become shorter
shear
force that pushes on a rock body in an uneven manner, causing it to become skewed such that different sides of the body move in opposite directions
Which of the following is not a common problem associated with volcanic ash-fall?
forest fires
gas giants
four outermost planets that are largely composed of hydrogen and helium gas and have surfaces marked by clouds of swirling gases
terrestrial planets
four planets closest to the Sun that have outer shells composed of rocky, earth-like materials
fault
fracture plane along which slippage or movement has occurred along opposite sides of the fracture
sediment
fragments of rock and mineral grains that are produced when rocks are broken down by undergoing physical weathering
natural vibration frequency
frequency at which a building will naturally vibrate when the ground shakes during an earthquake
Downslope movement occurs when the ___ becomes less than the ___ in the slope direction
frictional forces; gravitational force
Here, a cloud of dust and gas begins to spin as it collapses. Eventually, the density in the middle of cloud becomes high enough for nuclear ___ to begin, forming a star.
fusion
mass wasting
general process of earth materials moving downslope due to gravity; the terms landslide and avalanche are often used synonymously, but technically involve specific types of movement
radiometric dating
general term applied to absolute dating techniques involving any type of radioactive element and its decay product; since different radioactive elements decay at different rates, scientists can obtain reliable dates for events ranging anywhere from thousands to billions of years old
relative age
geologic age of a rock, fossil, or event in relative terms as compared to the age of another rock, fossil, or event; relative age of sedimentary layers is based on the principle that the bottom layers were deposited first, thus are the oldest
rock cycle
geologic concept that describes the recycling of rocks from one rock type to another by various geologic processes
geological hazard
geologic condition, natural or artificial, that creates a potential risk to human life or property; examples: earthquakes, volcanic eruptions, floods, and pollution
Of concern is the possibility that ___ could destabilize the planet's sensitive climate system, causing civilization to face ___ changes in the climate
global warming; dramatic
Another concern is that a newly exposed Arctic Ocean would alter existing ___ patterns in ways not yet understood
global weather
The vast majority of climate researchers believe that this trend is a response of the Earth system to the sudden change in ___ in the atmosphere
greenhouse gases
Which of the following are considered climate feedback mechanisms?
greenhouse gases and reflection/adsorption of sunlight
earthquake
ground shaking associated with the vibrational wave energy that results when a rock body suddenly fails and releases its accumulated strain
Which of the following best describes the phenomenon known as liquefaction?
ground shaking causes saturated sandy materials to behave as a liquid
clay minerals
group of aluminum rich, silicate minerals that typically form by the chemical weathering of other silicate minerals
feldspars
group of rock-forming silicate minerals that are rich in aluminum (Al), and are commonly transformed into clay minerals by chemical weathering
galaxies
groupings or clusters of stars within the universe, some of which form a planar, rotating disk of stars
How do hydrologists measure the severity of floods?
height (stage) above which a stream overflows its banks
flood stage
height at which a river begins to overflow its banks. Stage height changes along a river because the channel continually decreases in elevation as it moves downstream
The viscosity of this magma would decrease if the temperature was ___ and/or its SiO2 content was ___
higher; lower
Which term refers to a scientific explanation of data that can be tested in such a way that shows it to be false?
hypothesis
seafloor spreading
hypothesis that describes how new oceanic crust forms as mid-oceanic ridges spread or open up over time, and are then filled by erupting magma
Sea level is expected to rise due to continued melting of the Antarctic and Greenland ice sheets. Which of the following best describes why climatologists are likely to have underestimated the rate of sea level rise?
ice sheets are melting from within as water flows down through fractures
As the slope increases, the component of gravity in the slope direction (Gs) operating on a rock will ___
increase
As Earth's climate system gains additional heat energy, evaporation rates will ___. This and the fact that a warmer atmosphere is capable of holding ___ water vapor should result in ___ unusually heavy rain and snow events
increase; more; more
Which of the following best explains why excessive amounts of water can destabilize a slope?
increases internal pore pressure
ions
individual atoms that have either gained or lost electrons, thereby acquiring either a positive or negative electrical charge
tectonic plates
individual slabs of the brittle lithosphere (crust and upper mantle) that move over the relatively weak asthenosphere
inner core
innermost part of the Earth that consists of a solid metallic sphere
seismographs
instruments that are used to measure (quantify) the amount of ground motion during an earthquake
Which of the following best describes the Mercalli earthquake scale?
is a qualitative measure of earthquake intensity
In a sequence of sedimentary rocks, the oldest layer ___.
is at the bottom and is overlain by progressively younger layers
What best describes a drainage basin?
land area that collects water for a given network of streams
drainage basin
land area that collects water for an individual stream or river; also referred to as a watershed
island arc
landmass surrounded by ocean, which forms when magma rises up through a buckled tectonic plate along a subduction zone, producing a string of volcanic islands
Today we know that large impacts can still occur due to the discovery of ___
large Earth-crossing asteroids and comets
Which of the following best explains why urbanization has led to larger and more frequent floods?
large areas of land are covered with impermeable surfaces
ground fissures
large open cracks that form over a wide area of the landscape during an earthquake
shield volcanoes
large volcanic landforms that are composed primarily of a series of basaltic lava flows
downstream flood
large volume flood that tends to rise slowly and stay above flood stage for extended periods of time; commonly occurs in the lower portion of drainage systems where streams have wide channels and natural floodplains
Earthquakes commonly cause structural damage because buildings are not normally designed to withstand ___, which develops from the combination of ___ and the horizontal ground motion of the earthquake
lateral shearing motion; their own inertia
Which of the following is least likely to be associated with explosive volcanic eruptions?
lava flows
The scientific law that describes the age relationship between sedimentary rock layers is called the ___
law of superposition
Artificial levees also encourage development within floodplains, which ___
leads to greater damages when levees fail
One important consequence of global warming is that Earth's climatic zones are expected to shift. Which of the following would affect large parts of Earth's population as winters arrive later and end earlier?
less melt water to sustain streams during the summer months
One important consequence of global warming is that Earths climatic zones are expected to shift. Which of the following would affect large parts of Earth's population as winters arrive later and end earlier?
less melt water to sustain streams during the summer months
rift valley
linear valley, also called a graben, that forms when tension forces cause the land to down-drop in a stair-step fashion along parallel faults
outer core
liquid metallic shell within the Earth that surrounds the solid metallic inner core
climate
long-term average weather and its statistical variation for a given region: contrasts with weather, which refers to the state of Earth's atmosphere at any given time and place
Because this warms Earth surface, the planet itself emits electromagnetic radiation where the wavelengths are in the ___, infrared portion of the spectrum
longer
Streams located near the mouth of a river are quite different compared to those near the headwaters. What best characterizes streams near the mouth?
low velocity, high discharge, and meandering channels
land subsidence
lowering of the land surface due to the closing of void spaces within subsurface materials; commonly triggered by the withdrawal of subsurface fluids (water or oil) or by the collapse of natural cavities or mining voids
base level
lowest level to which a stream can erode its channel; sea level is often referred to as ultimate base level because the oceans represent the end or low point of most rivers
mouth
lowest point in a drainage system where a river discharges into an ocean, lake, or another river
Which of the following factors determine whether a volcanic eruption will be explosive or non-explosive?
magma viscosity and gas content
igneous rocks
major class of rocks that form when minerals crystallize from cooling magma
metamorphic rocks
major class of rocks that form when preexisting rocks are altered by some combination of heat, pressure, and fluids
sedimentary rocks
major class of rocks that form when weathered rock fragments, or mineral grains that chemically precipitate from dissolved ions, are reassembled to form a layered rock sequence
theory of plate tectonics
major theory in geology that describes how Earth's lithosphere is broken up into rigid slabs that are in motion due to forces associated with the planet's interior heat
Which of the following provide scientists with evidence that Earth's interior has distinct layers?
mapping of the deep ocean floor
elastic limit
maximum amount of strain that a rock body can accumulate before either fracturing or undergoing plastic deformation
Which of the following best describes the Richter and Moment earthquake scales?
measures the amount of ground motion and energy released
Which of the following best describes Earth's outer core?
metallic liquid
Which of the following statements best describes the first life-forms on Earth, which existed about 3.6 billion years ago?
microbial life began at a time when the planet's atmosphere and climate were very different
quartz
mineral composed entirely of silicate ions and commonly found in continental crustal rocks along with feldspars. Because it is resistant to chemical weathering, quartz is also abundant in soil and sediment
volcanic mudflow
mixture of ash, rock, and considerable amounts of water that tends to rush down the stream valleys that lead away from a volcano; also called a lahar or debris flow
moment magnitude scale
modern earthquake magnitude scale that provides a more accurate measure of the amount of ground motion
magma
molten rock material that forms within the Earth and can cool to form igneous rock; lava is used to describe magma that cools on Earth's surface
Ocean acidification is taking place as the oceans absorb some of the additional carbon dioxide in the atmosphere. What is the basic environmental problem that this creates?
more difficult for marine organisms to secret their own protective shells
If the viscosity of this magma decreased, it would become ___ fluid-like, which means it would travel a ___ distance
more; greater
Which of the following statements best describes P-waves?
move in a compressional manner and are the fastest type of seismic wave
sediment pollution
movement of excessive sediment off the landscape and into drainage systems; channels can become filled with sediment, destroying the ecology of streams and increasing the frequency and severity of flooding
In addition to causing buildings to collapse and failure of mechanical and electrical equipment, volcanic ash can mix with heavy rains to form dangerous ___
mudflows
ocean trenches
narrow, steep-sided depressions associated with subduction zones that run parallel to adjoining landmasses
transportation
natural process of moving earth materials from one location to another through some combination of gravity, running water, glacial ice, and wind
greenhouse effect
natural warming of Earth's atmosphere due to the presence of certain gases, which absorb outgoing radiation and release the corresponding heat energy into the atmosphere
mineral
naturally occurring inorganic solid composed of one or more elements in fixed proportions, and where the individual atoms have an orderly arrangement called a crystalline structure
The ___ is the widely accepted scientific explanation for the origin of the solar system
nebular hypothesis
Which of the following is not a greenhouse gas?
nitrogen (N2)
The rocks making up the seafloor gets progressively ___ away from the mid-ocean ridge
older
This pattern results from ___ that trigger a change in Earth's heat balance, followed by ___ that amplify the initial change, and ___ feedbacks that keep the system in check
orbital variations; positive; negative
Richter magnitude scale
original earthquake magnitude scale, developed by Charles Richter, used to quantify the amount of ground motion
global warming
overall rise in the average global temperature of Earth's atmosphere; term is commonly used to refer to the current warming trend
natural levees
pair of sand ridges that run parallel to stream banks, and form over time as a river overflows its banks and experiences an immediate decrease in velocity, causing sediment to fall from suspension
foliated texture
parallel realignment of minerals within a rock caused by the increased pressure associated with regional metamorphism
pyroclastic material
particles of pulverized rock and lava that are ejected into the surface environment during explosive volcanic eruptions
As shown here, artificial levees provide protection against flooding, but make flooding worse upstream because ___
parts of the floodplain are no longer able store floodwaters
La Nina
pattern of water and air currents in the Pacific Ocean that sometimes follows a periodic El Niño event, suppressing rainfall along the western United States
El Nino
periodic change in water and air currents in the equatorial parts of the Pacific Ocean, which bring dry conditions to the western Pacific and heavy rains to parts of coastal North and South America
ground amplification
phenomenon that occurs when seismic waves encounter weaker materials and begin to slow down, causing an increase in wave amplitude and ground shaking
resonance
phenomenon that occurs when the natural vibration frequency of a building matches that of the seismic waves, causing the building to shake more violently
inertia
physical tendency of objects at rest to stay at rest, which plays a key role in causing damage during earthquakes when structural foundations are suddenly forced to move
This figure illustrates a rock undergoing the process known as frost-wedging, which is an example of ___
physical weathering
epicenter
point on the surface that lies directly above the focus, which is the place where an earthquake originates in the subsurface
focus
point within a rock body where accumulated strain is suddenly released, causing an earthquake
The weight of this additional water causes the ___ pressure within the voids to increase, which reduces the friction between the solids
pore (fluid)
This sets up a ___ feedback, where the warmer ocean temperature ___ the rate of ice loss, which leads to even higher ocean temperatures and melting
positive; increases
pore pressure
pressure from fluids (water, oil, or gas) within the void spaces of rocks that acts outward in all directions
scientific method
process by which the physical world is examined in a logical manner; data or facts are gathered via observations or experiments, which are then explained through hypotheses, theories, and laws
subduction
process of one lithospheric plate descending beneath another, where it then undergoes melting and becomes incorporated into the mantle
carbon sequestration
process of removing carbon from the surface environment and placing it in storage for long periods of time; can occur naturally (formation of limestone rock and fossil fuels) or artificially by humans (subsurface injection of carbon dioxide)
physical weathering
process that causes rocks to disintegrate into smaller pieces or particles by some mechanical means
hydraulic sorting
process where flowing water separates sediment grains based on their size, shape, and density
ocean acidification
process where the acidity of the oceans increases over time due to higher carbon dioxide levels in the atmosphere. As the oceans absorb additional carbon dioxide, the dissolved gas is converted into carbonic acid, making the oceans more acidic
deposition
process where transported earth materials begin to accumulate; solid sediment will accumulate in low-lying areas of the terrain, whereas dissolved ions accumulate in either a body of surface water or a groundwater system
overland flow
process where water moves downslope in thin sheets over the land surface
accretion
process whereby planets eventually form when gravitational attraction causes individual particles to clump together into larger masses
erosion
process whereby rock or sediment is removed from a given area through chemical reactions or by being physically picked up or worn down by abrasion
triggering mechanisms
processes or events that lead to a mass wasting event by reducing the frictional forces on a slope and/or increasing the effect of gravity
climate feedbacks
processes within the Earth system that respond to a disruption in the planet's heat balance and act to further increase or decrease the energy imbalance
What best explains why glacial ice cores are ideal for examining climatic conditions in Earth's past?
provide high-resolution data on both temperature and carbon dioxide
What best explains why groundwater baseflow is important to maintaining a healthy stream ecosystem in humid climates?
provides streams with a steady flow of water during dry periods
Mercalli intensity scale
qualitative means of ranking the intensity of earthquakes based on first-hand human observations, particularly the amount of structural damage
This type of dating uses radioactive elements and their decay products to determine an absolute age for an earth material
radiometric dating
Which of the following natural factors affect the degree or severity of flooding?
rainfall volume and infiltration capacity of the ground
Which of the following best explains why some volcanoes erupt so violently?
rapid decompression of dissolved gases
volcanic landslide
rapid downslope movement of rocks, snow, and ice that can occur when the steep flanks of a volcano become unstable and then fail; also called a debris avalanche
stream gradient
rate of elevation change or steepness of a stream channel. Water velocity increases in areas where the gradient is higher
geothermal gradient
rate of temperature increase in the Earth with increasing depth
ecological footprint
refers to the amount of biologically productive land/sea area needed to extract the resources needed by humans, and to absorb the waste they generate
carbon cycle
refers to the cyclical and natural movement of carbon atoms through Earth's solid interior and surface environment (biosphere, hydrosphere, and atmosphere)
The nature of volcanic eruptions is closely related to plate tectonics and magma type. Which of the following best describes basaltic magma?
relatively SiO2 poor and hot
habitable zone
relatively narrow zone around a star where the surface temperature of orbiting planets would be such that liquid water could exist, creating a greater potential for the development of life
comets
relatively small bodies, 0.6 to 6 miles in diameter, composed of small rocky fragments embedded in a mass of ice and frozen gases; most have highly elliptical orbits around the Sun
rock-forming minerals
relatively small set of minerals that make up most of the rocks in Earth's outermost layer, called the crust
cinder cones
relatively small volcanic features that form when lava is ejected into the air and cools into cinders, which then fall and accumulate around the vent
There are two basic types of volcanoes, shield and composite cone. Which of the following best describes composite cone volcanoes?
relatively small, erupt andesitic magma, and are highly explosive
Because Earth operates as a system, we can expect that these changes will ___ the entire system
ripple through
hot spots
rising plumes of mantle material that cause partial melting in the overlying lithospheric plate, creating magma that moves upward through weak zones within the plate
Volcanic ash is composed of ___ which makes ash very ___
rock & glass fragments; abrasive
ferromagnesian minerals
rock-forming minerals that contain relatively high proportions of iron (Fe) and magnesium (Mg)
lithosphere
rocks from both the crust and upper mantle, forming a brittle layer that is broken up into individual tectonic plates that move over the relatively weak asthenosphere
mantle
rocky shell surrounding Earth's metallic center that is composed of iron-rich silicate minerals
Rain or melting snow will infiltrate and eventually cause subsurface voids between fractures and sedimentary grains to become ___
saturated
big bang theory
scientific explanation for the origin of the universe in which all matter at one time existed at a single point, but then about 14 billion years ago began expanding outward in all directions
hypothesis
scientific explanation of data or facts; must be testable such that it is possible to show them to be false or incorrect; supernatural explanations are not considered scientific because they are not testable and cannot be shown to be false
rare earth hypothesis
scientific idea that life is probably common throughout the universe, but complex animal life similar to Earth's is likely to be exceedingly rare
Which of the following refers to the process by which the physical world is examined in a logical manner?
scientific method
law
scientific term that describes some phenomena in which the relationship between different data occurs regularly and with little deviation; such a relationship often can be described in terms of mathematics
theory
scientific term used to describe the relationship between several different and well-accepted hypotheses, providing a more comprehensive or unified explanation of how the world operates
This provided some of the first direct evidence that the ___ hypothesis was correct
seafloor spreading
Excessive ash can also lead to ___ in streams, which in turn can cause ___
sediment pollution; increased flooding
primary (P) waves
seismic waves that cause solid particles to vibrate in the same direction the wave is traveling such that the rocks alternately compress and decompress
secondary (S) waves
seismic waves that cause solid particles to vibrate perpendicular to the wave path, which creates a shearing (side-to-side) motion
surface waves
seismic waves that travel along Earth's surface; examples include Rayleigh and Love waves
body waves
seismic waves that travel through Earth's interior, which includes primary (P) waves and secondary (S) waves
This 2,000-year record illustrates how human civilization is ___ to variations in climate. One of the key lessons from the entire 50,000 year record (blue) is how remarkably ___ the climate system has been for the past 10,000 years, a period when human civilization began to flourish
sensitive; stable
Which of the following is not part of the hydrologic cycle?
sequestration
tsunami
series of ocean waves that form when energy is suddenly transferred to the water by an earthquake, volcanic eruption, landslide, or asteroid impact
gamma-ray burst
short-lived burst of very high energy waves that can destroy ozone molecules in the upper atmosphere, which shield the biosphere from dangerous ultraviolet radiation
The graph in (B) provides evidence of global warming as it shows a ___ in the number of years when global temperatures have been above the recent long-term average
significant increase
Which of the following elements makeup most of the rocks in Earth's crust?
silicon and oxygen
Which of the following lines of evidence was used by Alfred Wegener to support his theory of continental drift?
similar plant & animal fossils on different continents
asteroids
small bodies orbiting the Sun that are composed primarily of rocky and metallic materials; most lie in what is known as the main asteroid belt between Mars and Jupiter
planets
solar system bodies that are large enough that their gravity is able to dominate their orbital zones, sweeping it clear of debris
general circulation models (GCMs)
sophisticated mathematical models that use a three-dimensional grid to simulate atmospheric processes on a global scale, including the many feedbacks between the atmosphere, oceans, and land
weather
state of Earth's atmosphere at any given time and place; contrasts with climate, which represents the long-term average weather and its statistical variation for a given region
recurrence interval
statistical calculation representing the frequency at which a particular value of stream discharge can be expected to repeat itself
wave attenuation
steady decrease in seismic wave energy that occurs as the waves travel away from their point of origin at the focus
lava domes
steep-sided mound of cooling lava that is built from more viscous magma that does not flow very readily
carbon tax
strategy for reducing carbon emissions by levying a tax on fossil fuels, thereby providing an incentive for businesses and industries to switch to non-carbon-based energy sources
cap-and-trade system
strategy for reducing carbon emissions where regulators provide permits and set emissions limits for a particular type of user. Because users are allowed to buy and sell individual permits, a financial incentive exists for operators to develop more efficient systems, or switch to a cleaner fuel
physical geology
study of the solid earth and the processes that shape and modify the planet
geology
study of the solid earth, which includes the materials it is composed of and the various processes that shape the planet
During which of the following processes is oceanic crust recycled?
subduction
Which of the following tectonic settings is the most likely to generate an explosive volcanic eruption?
subduction zone
glacial surge
sudden and rapid increase in the flow of glacial ice, believed to be triggered by the buildup of meltwater at the base of glacier, which reduces the friction between the glacier and underlying bedrock
What do climatologists fear might happen if the Earth system crosses a climate threshold?
system will enter a period of abrupt and dramatic climate change
silt fences
technique for reducing sediment pollution and flooding; consists of a barrier, placed downslope of construction sites, made of a synthetic fabric that is fine enough to trap sediment, but yet allows some water to pass
carbon capture and storage
technique under development for removing carbon dioxide from the emission gases of industries burning fossil fuels, then compressing the CO2 and injecting it into permeable rock formations for permanent storage; also see carbon sequestration
terracing
technique where a series of flat surfaces are cut into a hillside, with retaining walls commonly used to support oversteepened portions of the slope. The flat areas (terraces) can be used for growing food, constructing buildings, or reducing the chance of rocks tumbling onto highways
convergent boundary
tectonic plate boundary that is dominated by compressive forces such that the two plates move toward one another
transform boundary
tectonic plate boundary that is dominated by shear forces such that the two plates slide past one another
divergent boundary
tectonic plate boundary that is dominated by tension forces such that the two plates move away from one another
Viscosity is the measure of a fluid's resistance to a flow. Which of the following factors affect the viscosity of magmas?
temperature and SiO2 content
Which of the following is the type of force that causes rocks to be extended, or pulled apart?
tension
snow avalanche
term used to describe mass wasting events involving snow as opposed to rock or sediment
thermohaline circulation
term used to describe the collection of large-scale density and wind-driven currents that move in a convective manner through the ocean basins. This circulation plays a key role in Earth's climate by transferring heat energy around the globe
albedo
term used to describe the fraction of solar radiation that is reflected off a solid body; light-colored objects, such as clouds and land covered with snow or ice, reflect more light and therefore have a high albedo
geologic time
term used to imply extremely long periods of time over which geologic processes take place, typically measured in intervals of millions or billions of years; human time is often measured in intervals ranging from seconds to decades
Which of the following statements best describe what geologists refer to as rock-forming minerals?
the few dozen or so minerals that make up most of the rocks in Earth's crust
The rock will begin to move only if the gravity component in the slope direction becomes greater than ___
the frictional resistance
Buildings and other structures are primarily designed to only withstand ___
their own weight against gravity
What best describes why volcanic mudflows are so dangerous to humans?
they move down stream valleys where people tend to live
The reason we find so few craters on Earth is largely because ___
they've been erased by weathering and erosion
Although predicting the future climate is difficult, what scientists know for certain is that the atmosphere is relatively ___ and that ___ is causing it to ___ additional heat
thin; human activity; retain
ozone depletion
thinning of the atmosphere's outermost layer, composed of ozone molecules, that shields the biosphere from dangerous ultraviolet radiation
lag time
time difference between a rain event and the resulting peak discharge in a stream
seismic gap
tool for predicting the likelihood of an earthquake, based on sections of an active fault where the strain has not been released for an extended period of time
drainage divide
topographic line that follows the crests in the landscape and marks the point where surface water is forced to flow into different drainage networks
Because the atmosphere is ___ to incoming solar radiation, most of the radiation strikes Earth's land and oceans, at which point the light rays are either reflected, or absorbed and transformed into ___ energy
transparent; thermal
A stabilization ___ represents the amount that carbon dioxide emissions to be reduced in order to keep future emissions at some stable level
triangle
Earthquakes, heavy rains, and removal of vegetation are considered ___ because they can ___ and cause earth materials to begin moving downslope
triggering mechanisms; upset the balance of forces
Earth's glacial periods are explained by orbital variations that produce a small temperature change, which is then amplified by changes in carbon dioxide concentrations
true
Geologists are able to study processes that form rocks here on Earth and then use this information to help interpret the geologic history of other planets
true
The term lava is used to refer to molten rock that makes it way onto Earth's surface environment
true
To slow the current warming trend, industrialized nations must reduce their overall rate of greenhouse gas emissions
true
Volcanic ash forms when rock particles and lava droplets are ejected skyward
true
When rocks are stressed beyond their elastic limit the deformation becomes permanent
true
oxidation/reduction
type of chemical weathering reaction in which electrons that are gained or lost take part in the breakdown of minerals, releasing both dissolved ions and producing new minerals called weathering products
dissolution
type of chemical weathering reaction in which minerals completely dissolve or disassociate in water, leaving only individual ions in the solution
hydrolysis
type of chemical weathering reaction in which water molecules directly take part in the breakdown of minerals, releasing both dissolved ions and producing new minerals called weathering products
limestone
type of clastic or chemical sedimentary rock that is composed chiefly of the mineral calcite
shale
type of clastic sedimentary rock that is dominated by fine, clay-sized particles
sandstone
type of clastic sedimentary rock that is dominated by sand-sized rock and mineral fragments
electromagnetic radiation
type of energy that travels in a continuous series of waves in which individual waves vary in terms of their wavelength and amount of energy they contain
flow
type of mass wasting involving loose material that accumulates enough water so that internal friction is reduced, allowing it to behave like a fluid and start flowing downslope
slide
type of mass wasting involving masses of rock, earth, or debris (mixtures of rock and earth) that moves in a sliding manner along a zone of weakness (bedding planes, faults, fractures, and foliation planes)
fall
type of mass wasting that involves the rapid movement of earth materials falling through air
headwaters
upper portion of a drainage network where there are numerous small channels, which eventually merge to form progressively larger streams
earthquake presursors
various physical phenomena that can occur just prior to the release of energy associated with a main earthquake shock
seismic waves
vibrational waves that travel through solid earth materials that are caused by earthquakes, sudden impacts, or explosions
continental arc
volcanic mountain range associated with a subduction zone in which magma rises up through a continental tectonic plate to form a string of volcanoes
stream discharge
volume of water moving through a channel over a given time interval, commonly measured in units such as cubic feet per second
The global temperature data from land- and sea-based measurements clearly indicate that the Earth is in a significant ___ trend
warming
What do climatologists not expect to see now that Earth's climate system has been pushed to a higher energy level?
warming trend to reverse in the near future
groundwater baseflow
water that moves through subsurface materials and then flows into the surface environment, such as a stream, lake, wetland, or ocean
athenosphere
weak zone within the Earth that lies near the top of the mantle where silicate minerals are near their melting points; tectonic plates ride over this weak layer
This can be accomplished through the collective contribution of individual stabilization ___, which represent different carbon dioxide ___ strategies, such as the use of wind and solar power, improved energy efficiency, reforestation, and conservation
wedges; reduction
mass extinction
when large numbers of Earth's species go extinct in a relatively short period of time
exponential growth
when the amount added over successive time increments keeps increasing such that it plots as a curve as opposed to a straight line
linear growth
when the amount added over successive time increments remains the same so that it plots as a straight line as opposed to a curve
geologic time scale
worldwide rock record classified according to the relative or chronological age of individual rocks; uses various names to subdivide Earth's rock record into progressively smaller time intervals
magma chamber
zone or reservoir of molten material that forms within the lithosphere