AGRY 290 Test 2

earthquakes represent a buildup of stress in the ____ (layer of earth)
planar breaks in rock along which there is displacement of one side relative to the other
when movement along faults occurs gradually and smoothly — rarely causes damage
creep or aseismic slip
earthquake (seismic slip)
when the stress of the earth moving exceeds the rupture strength of the rock and a sudden movement occurs
when rocks snap back to their previous dimensions after sudden displacement (earthquake)
elastic rebound
point on a fault at which the first movement or break occurs during an earthquake
focus or hypocenter
deep-focus earthquakes have focal depths over __km
the point on the earth’s surface directly above the focus
deep-focus earthquakes are concentrated in ___ zones. why?
subduction – because the deeper earth is more elastic and fluid
when an earthquake occurs, it releases the stored up energy in ____
seismic waves
P and S waves are ___ waves
__ waves are compression waves
__ waves are shear waves, involving side to side motion
____ waves are similar to surface waves on water because they cause rocks and soil to be displaced so that the ground ripples
seismic surface waves
most damage from earthquakes is caused by ___ waves
seismographs detect the epicenter using __ waves
P waves are known as ___ waves and S as ___ waves why?
primary, secondary – bc the P wave arrives before the S
the amount of ground motion is related to the ___ of the earthquake
___ is a better measurement of relative energy release of an earthquake bc it takes into account the area of the break on the surface, the displacement along the fault, and the strenght of the rock.
moment magnitude (Mw)
measure of an earthquake’s effects on humans and surface structure
most commonly used intensity scale in the US
modified Mercalli intensity scale – 1-12 intensities
seismic sea waves caused by an undersea or near-shore earthquake
dormant, quiescent sections of otherwise active fault zones
seismic gaps
implications of seismic gaps
represent “locked” sections of faults along which normal slipping is prevented… often represent spots of future, serious earthquakes
things that happen or rock properties that change prior to an earthquake
precursor phenomena
because earthquake predicting is not a refined science yet, the US tends to rely more on ____
earthquake forecasting
the earthquake cycle
the idea that major earthquakes occur at more or less regular intervals and follow a cycle along a fault segment that includes a period of stress buildup, sudden fault rupture in a major earthquake, a period of aftershocks, then another extended period of stress buildup
magma is typically generated at what 3 plate-tectonic settings?
at divergent plate boundaries (ocean ridges and continental rift zones), over subduction zones, at ‘hot spots’
isolated areas of volcanic activity that are not associated with current plate boundaries
hot spots
magma that is rich in iron and magnesium is referred to as ___. silica-rich magma is referred to as ___.
mafic, felsic
__ forms new sea floor and is caused
what kind of magma is more explosive?
silica-rich (felsic) because it tends to trap gases — whereas mafic tends to let gases flow through
The Pacific “ring of fire” is so seismically/volcanically active because ..?
it is a ring of subduction zones
Kilimanjaro is associated with ____ zones
continental rift
volcanic rock is ___ rock formed where?
igneous rock formed at or near the earth’s surface
most volcanic rock is created by ____.
seafloor spreading ridges
the eruption of magma out of a crack in the lithosphere, rather than from a single pipe or vent… happens at spreading ridges
fissure eruption
mafic basaltic lavas build volcanoes that are flat and low in relation to their diameter… this is called
shield volcanoes
the hawaiian volcanoes are ___ volcanoes
rhyolitic and andesitic lavas tend to build __ ]because of their thick, viscous nature. example of one of these?
volcanic domes – mt. st. helens
bits of violently erupted volcanic material
when pyroclastics fall close to the place where they fell near the mouth of the volcano, these form
cinder cones
volcanic “bombs”
blobs of liquid lava that are thrown from a volcano during an eruption
volcanoes that erupt some pyroclastics, then some lava, then more pyroclastics, and so on are called ____ because they are built up of varying layers.
composite volcanoes or stratovolcanoes
the cascade range in the western US, including my. st. helens are ___ volcanoes
How did the Icelandic island of Heimaey fight back against it’s volcanic eruption?
they ran metal pipes with cool water in front of the lava flow so that the lava cooled and solidified and thus stopped further flow
volcanic “mud” formed by the combination of volcanic ash with water
denser-than-air mixture of hot gases and fine ash forms a hot ____, AKA ____.
pyroclastic flow – nuees ardentes
when large quantities of water (often seawater on volcanic islands) seep down into the rock and are heated to steam by the hot magma, and then burst forth out of the volcano
phreatic eruptions
most famous phreatic explosion
Krakatoa in Indonesia (1883)
3 categories of volcanoes based on their activity
active, dormant, or extinct
an enlarged volcanic summit crater, which may be formed by either an explosion enlarging an existing crater or by collapse of a volcano after a magma chamber within has emptied
biofuels are primarily made from ____
pros of ethanol use
lessens dependence on oil, good for the economy (creates jobs), renewable resource, cleaner burning, disaggregated (not as many middlemen)
cons of ethanol use
instability (“bad years” for corn), land pressure (soil erosion, deforestation), water needs, price, crop displacement (everyone can’t grow corn), transformational costs (turning corn into ethanol), more ethanol per mile needed than gas
2 other ways to make ehtanol (than corn)
algae, sugar cane, cellulosic material (“throw away” parts of plants)
the ultimate source of energy is?
the sun
7 types of “raw energy”
wind, biofuel, hydropower, fossil fuels, geothermal power, tidal power, solar power
4 types of consumed energy
electricity, heat, gas, oil
4 types of used energy
plastic from petroleum, light, transportation, work
___ is the country that uses the most energy. ____ is the country that uses the most energy per capita.
US, United Arab Emerates
the total oil in the world is about ____ barrels. The total recoverable oil is about ____ barrels. The proven oil is about ____ barrels. Already consumed ___ barrels.
4 trillion, 2 trillion, 1.3 trillion, 0.8 trillion
we have about ___ years left of oil at this point and this consumption
why is natural gas being favored over oil and coal? how much of our total energy is natural gas?
it releases less CO2 – 25%
___ is made up of large accumulations of terrestrial plant material (lignin) buried into the waterlogged soil. The organic remains then gradually turn into ___, porous brown organic material, which contains about __% carbon
coal … peat .. 50%
peat, lignite, bituminous, and anthracite coal have increasing/decreasing carbon contents in that order
increasing (peat is about 50%, anthracite about 90%)
What country has the largest coal reserves?
What area has the largest oil reserves?
middle east
the fuel in oil shale is ____, which is organic materials in various stages of degradation. How is oil shale produced?
kerogen — must first be crushed then heated to distill out the hydrocarbons, which can then be refined to crude oil
___ are sedimentary rock containing a very thick, semi-solid, tar-like petroleum.
tar sands
the oil reserves in the ANWR give us about how much oil in the US? (Barrels and time)
3.2 Billion barrels — 1 year
ways to conserve energy
good lightbulbs, insulation, eliminating “standby” of electronics, transportation efficiency, etc
solar energy, in general, is about __% efficient
types of biomass
wood, compressed organics, peat, ethanol, biofuel
how is wind power proportional to velocity?
power is the cube of velocity (double wind speed, 8x as much power)
UV_ makes vitamin D. UV_ is considered the most damaging. UV_ is entirely absorbed before it reaches earth.
A, B, C
strength of UV radiation is directly related to ____.
Earth’s average albedo
climate change is due to shifting of energy into its ___ expression and thereby changing the _____ balance.
temperature, thermodynamic
in general, it gets colder as we move further into the atmosphere away from the earth’s surface with the exception of the _____. this is becaus?
thermosphere – because it absorbs UVC
deserts are created at about 30 degrees N&S latitudes due to _____
Hadley cells – trap air low against the earth
how does the ITCZ create a positive feedback system?
Itertropical Convergence Zone – low pressure heats up air and causes it to expand and rise, this creates a vacuum that pulls air in from the side and back out the top
evaporation releases/uses energy. condensation releases/uses energy.
uses, creates
heat associated with phase change of water
latent heat
energy for wind comes from?
why do winds at beaches change direction during the day from night?
the water stays about the same temp and the temp of the land changes — during the day, the land is warmer and wind blows out to the ocean, reverse at night
“merry go round effect” caused by the coriolis effect
like trying to throw a ball to someone standing in the middle of a merry go round — the middle (equator) goes faster than the outside (higher latitudes)
the coriolis effect makes the northern hemisphere bend left/right
key points about the coriolis effect
wind is created by pressure differences, there is a difference in ground speed at different latitudes
Winter: the ITCZ bends over __ and lags over ___.
land, water
in a low/high pressure system, heating at the surface causes water to heat and rise
air tends to flow from areas of ___ pressure to areas of ___ pressure
high to low
what creates the monsoons in india in july?
ITCZ is over india but the large mountain range forces air upward which creates huge thunderstorms
preindustrial CO2 concentration and current
preindustrial: 280, now: 390ppm
___ is the essence of climate change. why?
resonance due to the frequency of thermal energy in the air that resonates with CO2 and transfers energy to it
CO2 concentrations increase with ____
Things that cause global cooling
biomass burning, sulfate aerosols, aircraft contrails, stratospheric ozone
a slow moving river that goes through all oceans and brings warm salty water from the tropics to the extratropics — makes ireland warmer than it should be
thermohaline (ex: gulf stream)
main reason for current rising sea levels
thermal expansion of water
embodied energy/carbon
energy is contained in al the stuff we use – paper, food, etc – it takes energy to cut down a tree and make it into paper and then ship it to the store
___ tons of carbon emissions per year
9 billion
Kyoto Protocol
countries agreed to reduce emissions on average 5% below their 1990 level by 2010
framework convention on climate change
defined the problem of GHG in the atmosphere – almost every country signed it, but not everyone did something about it. established differential responsibility. 1994
mid-oceanic ridge formed by rocks separating the ocean – one side is america, the other is europe
iceland ridge
subduction zone
oceanic plate slides under land and melts then bubbles up and is released via volcanoes — created san andreas fault
most fatal earthquakes are a combination of what 3 things?
strength of earthquake, number of people in the area, quality of structures in the area
tidal bore
miniature tsunami
layers of the earth – out to in
crust, upper mantle, asthenosphere, outer core, inner core
the lithosphere is made up of what layers?
uppermost mantle and crust
there are how many major plates in the earth?
a subduction zone “ate” the mid-ocean ridge in the pacific NW US and resulted in the strike slip san andreas fault
Sumatran tsunami in 2004
earthquake in ocean 60 mi offshore set off tsunami for over 10 hours and struck 12 countries, 150,000 killed
characteristics of earthquakes that generate tsunamis
epicenter underneath or near the ocean, fault that causes vertical movement of the sea floor over a large area, magnitude over 7.5 and focus under 70km
3 general appearances of a tsunami wave
fast-rising tide, cresting wave, step=like change in water level that advances rapidly
how does global warming effect arctic animal populations
ice sheets melt, krill that eat algae off them die, whales and penguins that eat krill die also
___ circulate air in the troposphere to constantly redistribute air around the world
convection currents
4 layers of the atmosphere (ground up)
troposphere, stratosphere, mesosphere, thermosphere
solar radiation
surfaces that reflect light have low/high albedo
energy that is released by the earth to the atmosphere
terrestrial energy
the greenhouse effect is created by ___ energy
terrestrial — lets light through but traps heat
large convection currents that distribute heat globally
hadley cells
high/low pressure = rising air
areas of frequent low/high pressure tend to get the most rain
hurricane-force winds at the top of the troposphere that circle the earth
jet streams
regular seasonal winds and rain
wherever the sun shines most/least brightly is where the strongest convection currents, rainfall, and storms are
cold front
cold air displaces warmer air and moves under it – generates strong convection currents and thus strong storms
which is caused by the coriolis effect: hurricanes or tornadoes?
how do we get knowledge about climate patterns throughout history
glacial ice cores
milkanovitch cycles
periodic changes in the earths orbit and tilt – cause dramatic climate swings
___ happens every 3-5 years when ocean temperatures rise. ___ happens in the intervening years
el nino, la nina
el nino southern oscillation – overall cycle of el nino and la nina
effect of el nino in US
dryer areas tend to get more rain, wetter areas are dryer
5 greenhouse gases
CO2, CH4, CFCs, N2O and SF6
global warming pros
more CO2 helps plants fluorish, warmer temps = longer growing seasons, stronger storms = less drought
global warming cons
increase in sea level (more floods), stronger storms/hurricanes, increase in infectious disease due to more bugs, release of methane hydrate from melting permafrost
Carbon enrichment studies – FACE
free air carbon enrichment – plants do better with more carbon
reducing output of GHGs
natural gas instead of coal, promote energy efficiency, raise gas taxes, nuclear power, wind energy
carbon management strategies
plant trees, phytoplankton, crop rotation, collect methane for energy, reduce soot emissions, pump CO2 into deep oceans
energy sources that formed from the remains of once-living organisms
fossil fuels
5 fossil fuels
oil, natural gas, coal, oil shale, tar sand
most common natural gas
fossil fuels take at least ___ years to form and are thus nonrenewable
2 million
“proven resources”
accumulations of fossil fuels that can be gotten with current technology
fossil fuels are really only found in land that is made up of ___ rock
primary oil recovery
recovery using no technology other than drilling
secondary oil recovery
pumping in water to fill pore spaces and buoy up the oil by increasing pressure
between primary and secondary recovery, we are able to recover about how much of the oil in a given well?
alternatives natural gas sources
coal-bed methane (methane gas produced by coal formation), geopressurized zones (deep in the earth, increased temp and pressure change oil to gas that is absorbed into the underground water), methane hydrates (crystalline solids of gas and water molecules found in the arctic and oceans)
pattern of US energy consumption
flattened in 70s and 80s, rose in 90s, flattening again
___ is an energy source formed from the remains of land plants
hard/soft coal has highest carbon content and is thus most desirable as fuel
environmental impact of coal – produces ___ when burned
CO2 — also releases sulfur which can cause acid rain
what is the most commonly used ion for fission
most uranium is found in ___ rock
a material that slows neutrons running through the core of a nuclear reactor enough that a chain reaction can be sustained
moderator — US is water, Chernobyl was graphite
___ is the process by which the sun makes energy
gasohol and it’s limitations
90% gas, 10% alcohol — normal cars can’t run on greater than 10% alcohol
sulfur dioxide is primarily emitted by
fossil fuel combustion
a temperature inversion can do what 3 things
decrease vertical mixing, increase photochemical smog, lessen visibility
unpolluted air has a pH of about
the US clean air act was first passed in
3 places CFCs are used
aerosols, catalytic converters, rubber production
pollutants that do not go through a smokestack
fugitive emissions
which criteria pollutant has not declined since 1970
why are the world’s deserts located at 30 degrees N&S latitudes?
large scale sinking air occurs in these regions
nitrogen and oxygen make up whta percent of background air in the atmosphere?
what is primarily responsible for the current and projected rise in global mean temperature?
human-produced gases
a surface with high albedo will do which: appear dark, reflect energy, destory ozone
reflect energy
what direction does the wind curve in the Southern hemi? and why?
left – coriolis effect
largest overall contribution to golbal warming is
3 processes that form clouds
heating at the planet’s surface, condensation of water vapor, expansion of rising air
how many modes of variation are present in milankovitch cycles?
OPEC stands for
organization of petroleum-exporting countries
3 types of fossil fuels
petroleum, natural gas, coal
the largest proven reserves of natural gas are in
___ solar heating typically requires few or no moving parts, uses direct sunlight, combines sunlight with a storage medium
photovoltaic solar energy uses ___ radiation to generate ____.
shortwave radiation to generate electrical current