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groundwater is being withdrawn at ________ rates that it is being recharged, _______ the volumes stored within many aquifers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