Geology Exam 3

permeability tends to be higher in ______

rocks with high porosity

high porosity & permeability

sand, gravel, some limestones, fractured igneous

The Earth's albedo can be altered over a geologically short period of time due to rapid changes in the amount of

sea ice

aquifer

sediments/rocks that can transmit and store water through the subsurface

aquitard

sediments/rocks that prevent water from moving through them

low permeability

shales, some limestones, unfractured igneous, salt

tsunamis are predominantly generated at _____

subduction zones

5 major mass extinctions since multicellular life evolved

1. End Ordovician (444 Mya) 2. Late Devonian (372 Mya) 3. End Permian (252 Mya) 4. End Triassic (201 Mya) 5. End Cretaceous (66 Mya)

freshwater reservoirs: ice _____, groundwater _______, surface & atmospheric water ______

69%, 30%, 1%

although _____ of the Earth's surface is covered in water, only ______ of water is freshwater

71%, 3%

Milankovitch Cycles

Precession (wobble), Obliquity (tilt), Eccentricity (orbit)

all organic compounds are based on _____

carbon

nearly perfect correlation between atmospheric CO2 levels and ______

cumulative CO2 emissions over the last 140 years

significant correlation between global temperature anomaly and ________

cumulative CO2 emissions over the last 140 years; atmospheric CO2 levels over the last 140 years

atmospheric CO2 levels have increased every year since 1960

currently at 420 ppm, much higher than at any time in the last 800,000 years

scientific theory

general principle that explains the how and why of multiple observations, and has been tested and proven many times

over the last 2.5 million years, the northern hemisphere has cycled bweteen ______

glacial and inter-glacial periods

evidence of glacial and inter-glacial periods

glacial topography, till, erratics, fauna, sea level, oxygen isotopes

thermohaline cicrulation =

global conveyor belt

long term carbon cycle years

greater than 10,000 years to hundreds of millions of years

three types of ground failure produced by earthquakes

ground shaking, landslides, liquefaction

faster; reducing (negative flux)

groundwater is being withdrawn at ________ rates that it is being recharged, _______ the volumes stored within many aquifers

evidence for global climate change

higher than average global temperatures for every year since 1980, decreasing sea ice and glacial ice volumes, increasing ocean temperatures, increasing global sea level, increased frequency widespread coral bleaching events

during much of the last 540 million years, the Earth has been a _______

hothouse without polar icecaps

long term climate cycles, cycle bwteen ______

hothouse, cool, and icehouse conditions

geysers and hotsprings are ______

hydrothermal features produced by the heating of groundwater by magma

long term carbon cycle: weathering of silicate-rich rocks enables ______

increased carbonate formation

in the water cycle, energy is provided by the _____

sun and gravity

the rate of change is as important as ______

the change itself

the long term carbon cycle encompasses the carbon flux between _____

the deep lithosphere and the other spheres (biosphere, hydrosphere, atmosphere)

since atmosphere is smallest reservoir, _______

the percentage gain is exacerbated

water cycle

the process by which water moves throughout the Earth's sphere

life has the ability to adapt or evolve to changing conditions, but not when _____

the rate of change is in the hundreds to thousands of years

Recent rising sea levels are primarily a result of ________

thermal expansion of warmer ocean waters

Temperatures have been above average for every year since 1980

true

ancient oceans often had circulation patterns ______

very different from our modern oceans

long term carbon cycle: CO2 is emitted by ______

volcanism - often from subducted and melted carbonates

humans have altered the _____

water cycle

upwelling of nutrient-rich deep water masses occurs

where surface currents diverge due to prevailing wind conditions (high concentrations of nutrients and algae (phytoplankton))

irrigation; thermoelectric power generation

most freshwater is used for _____, followed by use in _____

tsunami characteristics

move very quickly, have long wavelengths, and can go across entire oceans

Oxygen Minimum Zone (hypoxic or anoxic)

occur undeneath nutrient-rich waters

extinction causes include ______

ocean and atmospheric warming, ocean anoxia, ocean acidification, ozone depletion/UV radiation, metal poisoning, and sea level changes

five major short term carbon reservoirs are ____

oceans (85%), biosphere including soil (5.6%), ocean sediments (3.9%), permafrost (3.8%), and atmosphere (1.3%)

earthquake fatalities are most often related to _____

poor construction (secondary to tsunamis and landslides)

geologic record shows relationship between

atmospheric CO2 levels and global average temperature

anthropogenic carbon emissions are ~ ______

100 times greater than volcanic emissions

long term climate cycles (tens - hundreds of millions of years) are driven by ______

CO2 volumes driven by plate tectonics and changes in the long term CO2 reservoirs

the timing of the milankovitch cycles and the strength of the sun have never changes through time

False

cycles are controlled by _______

Milankovitch cycles and albedo

the combination of _______ and _______ are responsible for the glacial cycles of the last million years

Milankovitch cycles; albedo effect

temperature anomaly

The difference between a measured temperature and the long term average value is the temperature

water masses; density, nutrient levels

_________ have specific physical and chemical properties, including _____ and ______

observation

a piece of evidence, data, or measurement

hypothesis

a proposed explanation or prediction to explain an observation(s) that can be tested (has not been proven)

tsunami

a series of waves produced by the displacement of water by earthquakes, volcanoes, or landslides

permeability

ability of a material to transmit fluids

End Cretaceous is the only mass extinction that is also associated with _____

an asteroid impact (Chicxulub)

the Milankovitch cycles are related to _____

angles of sunlight

drainage basin/watershed

any area of land where precipitation collects and drains off into a common body of water

ground shaking

can be enhanced by geology, especially unconsolidated sediments

the short term carbon cycle encompasses the carbon flux between the _____

biosphere, atmosphere, hydrosphere, and soil/sediments of the lithosphere

How have humans impacted the water cycle?

built dams that have created artificial reservoirs, increased runoff due to hardscapes, drained aquifers faster than they can be replenished

reservoirs and levees reduce flooding and store water ______

but have changed stream flow and impacted fish and other organisms

The total volume of Arctic sea and glacial ice has ______ by 1/3 since 1980

decreased

permeability decreases as grain size _______, so sands and gravels have _______ than shales (mudrocks)

decreases; higher permeability

thermohaline circulation is driven by

density contrasts produced by differences in temperature and salinity

long term carbon cycle: CO2 is stored by ______

deposition of carbonates, organic-rich shales, and fossil fuels

law

describes what will happen under certain conditions, but not how or why

all 5 mass extinctions are thought to be associated with _______

emplacement of Large Igneous Provinces (LIPs)

reef communities underwent severe ______

extinction events in all 5 mass extinctions

Carbon dioxide levels have been much higher over the last million years than they are today

false

karst

features produced by acidic groundwater moving through carbonate rocks (limestone, dolomite), including the formation of caves

hardscapes increase runoff _______

increasing flash flooding and decreasing infiltration

water-energy-food nexus

lack of water can negatively impact energy generation (thermoelectric and hydroelectric) and food production (irrigation)

density contrasts

large bodies of water are layered (stratified) due to ______

short term carbon cycle years

less than 10,000 years

rapid growth

predominant underlying factor in freshwater scarcity

surface ocean currents

primarily driven by a global wind system powered by solar heat flux

water cycle

process by which water moves through the Earth's spheres

precipitation

process that moves water molecules from the atmosphere to the geosphere or hydrosphere?

evaporation

process that moves water molecules from the hydrosphere to the atmosphere

percolation

process that moves water molecules through the geosphere (soil and rocks)

tidal currents

produced by the interactions of the Earth, sun, and moon (gravity)

porosity

proportion of a material made up of void (empty) space that can be filled with fluids

albedo

proportion of the incident light or radiation that is reflected by a surface

short term carbon cycle: photosynthesis stores carbon,

respiration releases carbon