unit 4 Flashcards
core
inner = solid, outer = liquid, mostly composed of iron
mantle
82% of earth’s volume and 67% of earth’s mass, asthenosphere, iron, silica, magnesium, oxygen
asthenosphere
“plastic rock”, outer molten layer, allows for plate movement
crust
outermost and thinnest layer, continental crust = 29% of earth’s surface, oceanic crust = 71% of eath’s surface
earth’s internal processes
gravity, convection currents, mantle plumes, heat from earth (deforms mantle so it flows)
heat from earth’s core
mantle deforms and flows, plates constantly move, convection cells, mantle plumes
convection cells
large “bubbles” of heated rock move
mantle plumes
molten rocks travel up a column, spread in radial pattern near crust
where can earthquakes and volcanoes b e found
along belts, at hot spots, or at plate boundaries
ring of fire
pacific plate boundary
lithosphere
outer shell, 20 plates, made of crustal rock and part of upper mantle
alfred wegener 1915 continental drift
continents were connected in a super continent (Pangaea) but they broke apart and drifted
evidence of continental drift
matching fossils found in africa and south america, mountains with similar structure, age, and mineral composition, ancient climates
pangaea
supercontinent, broke off into Laurasia and Gondwanaland
divergeant boundary
plates move in OPPOSITE directions, upwelling of material from mantle “sea-floor spreading”, newest land is closest to boundary
convergeant boundary
plates move together, destroying crust, subduction occurs
subduction
oceanic crust is denser than continental crust so it sinks under continental
oceanic-continental convergeance
oceanic and continental crust collide, ocean plate sinks below, plate melts and magma flows up = volcanoes, trench formation
oceanic-oceanic convergeance
oceanic crust collides from both directions, formation of volcanoes, trench formation
continental continental convergeance
continental crust collides from both directions, forms highest mountains in the world
transform boundary
plates grind past one another without producing or destroying crust, NO volcanoe formation
hot spot
usually hot area in mantle layer
hawaiin hot spot
pacific plates move past northwest at 9 cm per year, hot spot doesn’t move with plate = chain of volcanic islands produced
earthquake
vibration of earth produced by rapid release of potential energy caused by plate slipping along a fault
fault
large fracture in earth’s crust
surface waves
slowest, travel along earth’s outer layer, all other vibrations of seismogram
body waves
primary and secondary
primary body waves
travel through solids, liquids, and gases, 1.7 times faster than s-waves
secondary body waves
travel ONLY through solids
p waves on seismogram
first markings because they travel the fastest
s waves on seismogram
first larger waves
richter scale
measures wave amplitude and energy
time travel graph
used to see how far an earthquake traveled, looks at difference in arrival times of P and S waves
wave amplitude
each number is a 10x wave amplitude increase
wave energy
30x energy increase between each level
primary effects of earthquake
shaking, ground displacement
secondary effects of earthquake
rockslides, subsidence, fires, flooding, tsunamis, roads destroyedsoil liquefaction
Anak Krakatau
most powerful volcanic erruption in recorded history, located west of sumatra in indonesia
where do we find volcanoes
divergeant boundaries, convergeant boundaries, hot spots
magma
hot, molten rock that forms beneath earth’s surface
lava
molten rock that reached earth’s surface through volcanic vents
what’s inside magma
silica = determines viscosity (flow resistance)
what decides how violent a volcanic erruption is
temperature, silica composition, amount of gases dissolved; greater pressure = greater violence
affect of temperature on volcanic violence
temp increases = more energy in magma, dissolved gasses move faster, more collisions occur and pressure increases
affect of amount of gases dissolved on volcanic violence
more gases dissolved = more collisions in magma chamber, greater pressure
shield volcanoes
large volcanoes with gently sloping sides, made of liquid lava, usually occur at hotspots, less violent erruptions, shorter time between erruptions, lower viscosity
cinder cone volcanoes
small volcanoes with steep sides, frequently occur in groups, made of pyroclastic material
pyroclastic material
hot gas and volcanic solid fragments ejected during volcanic erruption
composite volcano
fromed by alternating layers of lava and rock fragments, tallest and most violent types, most common, “ring of fire”
cryptodome
part of volcano sinks in, sign that erruption will soon occur
after volcanic erruption
gases remain in atmosphere and go into clouds, cloud droplets reflect suns energy and help to cool the planet
soil
thin covering over most land
factors that affect soil formation
parent rock/material, time, climate, biota, soil food web, slope/topography, weathering
climate
most influential on soil formation, CO2 + water = carbonic acid in soil, temp affected decay rate, precip affects weathering
biota
adds to humus and fertility
slope/topography
steep = no soil due to gravity, flat areas = best soil, side of a mountain may block sun or receive more sun
slow process of soil renewing
rock weathering, deposit by erosion, decomposition by soil organisms
how soil is beneficial
provides nutrients, filters water
soil horizons
show layers of soil
o horizon
accumulation of plant litter
a horizon
topsoil - organic matter and humus
b horizon
subsoil - clay and nutrient minerals
c horizon
weathered pieces of rock
solid parent material
bedrock, unweathered
e horizon
heavily leached
color of topsoil
can infer soil fertility
dark brown and black topsoil
nitrogen rich
gray, bright red, and yellow topsoil
low in organic matter, need nitrogen enrichment
orange soil
soil is high in iron
infiltration
water penetrates soil
percolation
water moves downward
leaching
minerals and organic matter are carried from upper soil layers to lower soil layers
illuviation
leached material in lower layers of soil decomposes
spodosol
in colder regions, has good drainage leading to distinct layers
alfisols
temperate deciduous forest
mollisols
found in temperate, semiarid grasslands, fertile soil
aridsols
found in arid and desert regions, lack of precipitation, do not have distinct layers of leching and illuviation
oxisols
low in nutrient minerals, in tropical and subtropical areas, lots of precipitation, quick decomposition, lots of vegetation
clay
very fine particles, settles LAST
silt
fine particles, settles SECOND
sand
medium sized particles, settles FIRST
gravel
coarse to very coarse particles
soil texture
helps determine porosity and permeability
loam
best for growth, no one particle dominates over the other
porosity
measure of total amount of water soil can hold, clay has largest total volume of pore space = most porous
permeability
measure of amount of water that can pass through a substance, more pore space = more permeable, sand has high permeability, clay has low permeability
shrink and swell potential
higher porosity = will shirnk and swell more
soil depth
how far you can dig until you hit rock, indicates age and fertility
fertilizer labels
nitrogen, phosphorus, potassium
nitrogen
dna and proteins, most limiting factor in plant growth
phosphorus
root development and plant maturity, most limiting nutrient in soil
potassium
disease resistance, wilting prevention
soil pH
pH affects solubility of nutrient minerals, ranges from 4.0 to 8.0
pH is determined by
parent material, chemical nature of any water entering the soil, land management practices, activities of organisms living in the soil
freshwater usage rates
10% residential, 20% industrial, 70% irrigation
watershed
region from which surface water drains into a river, lake, wetland, or other body of water
headwaters
origin of a river, usually found at a mountain
divide
boundary between two or more watersheds
tributary
small stream that empties into a larger river
floodplain
area of low-lying ground adjacent to a river, formed mainly over vier sediments and subject to flooding, fertile soil
estuary
mouth of a river, freshwater is emptied into ocean, high variability in salinity and temp
reliable runoff
amount of water we can generally count of as a stable source of water annually
living on a floodplain
fertile soil, plenty of water for irrigation, river transportation, recreation, flatland suitbale for crops or building
zone of saturation
zone where all open spaces in sediment and rock are completely filled with water
water table
upper limit of zone of saturation
zone of aeration
area above the water table where openings in sediment and rock are filled with air
unconfined aquifer
groundwater source not trapped by a layer of rock
confined aquifer
groundwater trapped by a layer of rock above
recharge area
areas that water can get through to reach the zone of saturation
discharge area
area that water dumps into flowing runoff water
ogallala aquifer
world’s largest aquifer, runs from south dakota and wyoming to texas
urbanizagtion/urban sprawl
humans cover soil, remove vegetation, and replace with concrete, increasing runoff and flooding and decreasing water infiltration and aquifer recharge
agriculture
overuse of fertilizers = eutrophication, contaminated water, overuse of aquifers
industrialization
add pollution to water and degrade water quality
dams and water diversion projects
causes habitat destruction and flooding, prevents nutrient rich sediment from flowing downstream, prevents fish migration upstream, increased evaporation in reservoirs
deforestation
remove vegetation = increases soil erosion, decreases soil fertility
atmosphere
thin envelope of gases surrounding the earth, pressure, air density, temp change with altitude
trophosphere
inner most layer, weather occurs, biogeochemical cycling occurs, ozone = smog, 75% all atmospheric gases
stratosphere
2nd layer, less water vapor, increased good ozone, 95% of uv rays filtered
mesosphere
3rd layer, cold, low pressure, most meteors entering earth are burned up here
thermosphere
4th layer, temp varies 9close to sun but thin air), satellites orbit earth
exosphere
5th layer, space-atmosphere merger
weather
average temp and precip over a short period of time
climate
avergae temp and precip over long period of time
suns rays
more direct = higher avergae temps, stick to earth more intensely, shorter distance to earth = can concentrate on smaller area
global wind patterns
convection currents transfer heat from from equator to poles
coriolis effect
earth’s rotation influences direction of surface winds
factors driving ocean currents
wind, coriolis affect
heat islands
infrastructure replaces open land and vegetation, surfaces become impermeable and dry = urban regions become warmer than surrounding rural regions
urban heat islands cause
less vegetation to shade surroundings, more concrete to absorb heat
environmental issues of heat islands
elevated emissions of air pollutants and greenhouse gases, impaired water quality, general discomfort
how to reduce heat island impacts
increase vegetation for shade, use green roofs, use cool roofs to reflect heat, use cool pavements to reflect solar energy
el nino
warming of eastern pacific, cooling of atlantic, occurs every 5 years, reduces atlantic hurricanes, warmer and drier winters in west US, Asia, and Australia, cool and rainy in southeast US
la nina
warming of atlantic, cooling of pacific, occurs on and off with el nino, more atlantic hurricanes, warmer and dried in southeast US, cool and rainy in west US, asia, and austrailia
rain shadow effect
windward side of mountain receives precip, leeward side of mountain is dry
