Unit 4 - earth systems and resources Flashcards
core
dense mass of solid nickel, iron, and radioactive elements that release massive amount of heat
mantle
liquid layer of magma surrounding core, kept liquified by intense heat from core
asthenosphere
solid flexible outer layer of mantle, beneath the lithosphere
lithosphere
thin, brittle layer of rock floating on top of mantle (broken up into tectonic plates)
crust
very outer layer of the lithosphere, earths surface
divergent plate boundaries
- plates moving away from each other
- rising magma plume from mantle forces plates apart
what do divergent plate boundaries form
rising magma plume forces plates apart forming
- mid oceanic ridges
- volcanoes
- seafloor spreading
- rift valleys (on land)
convergent plate boundaries
- plates move towards each other
- leads to subduction (one plate being forced beneath another)
what do convergent plate boundaries form
subduction forms
- mountains
- island arcs
- earthquakes
- volcanoes
transform plate boundaries
- plates slide past each other in opposite directions
what do transform plate boundaries form
earthquakes
tectonic map can predict
ring of fire, transform faults, hotspots
ring of fire
pattern of volcanoes all around pacific plate
- offshore island arcs (japan)
where are there offshore island arcs
Japan
transform faults
likely location of earthquakes
hotspots
areas of especially hot magma rising up to lithospheres
- mid ocean islands (iceland, hawaii)
where are there hotspots
Iceland, Hawaii
what is soil?
mix of geologic (rock) and organic (living) components
- sand, silt, clay
- humus
- nutrients
- water & air
- living organisms
humus
main organic part of soil (broken down biomass like leaves, dead animals, waste)
what does soil do for plants
anchors roots of plants and provides water, shelter, nutrients for growth
what does soil do for water
filters rainwater and runoff by trapping pollutants in pore spaces and plant roots. clean water enters groundwater and aquifiers
what does soil do for nutrient recycling
home to decomposers that break down dead organic matter and return nutrients to the soil
what does soil do for habitat
provides habitat for organisms like earthworms, fungi, bacteria, moles, slugs
weathering vs erosion
weathering is the break down and erosion is the movement
soil horizon: o
organic
- litter layer
- organic matter deposited by organisms
soil horizon: a
topsoil
- some organic material mixed with mineral components
soil horizon: b
subsoil
- minerals and organic matter accumulate here
soil horizon: c
weathered rock
- initial step in soil formation
soils are formed when
parent material is weathered, transported, and deposited
soils are generally categorized by
horizons based on their composition and organic material
soils can be eroded by
winds or water
loss of topsoil
- tilling + loss of vegetation disturbs soil and make it more easily eroded by wind + rain.
- loss of topsoil dry’s out soil, removes nutrients + soil organisms that recycle nutrients
compaction
compression of soil by machines (tractors, bulldozers), grazing livestock, and humans reduces ability to hold moisture
- dry soil erodes more easily
- dry soil supports less plant growth, less root structure
tilling
turning soil for agriculture
nutrient depletion
repeatedly growing crops on the same soil removes key nutrients (N, P, K, Na, Mg) over time; reduces ability to grow future crops
soil particles
sand silt clay
soil texture
the % of sand, silt, clay in a soil always adds up to 100%
porosity
the amount of pore space a soil has
- how much (volume of) water that a soil sample can hold
permeability
the opposite of porosity, how easily water drains through the soil
water holding capacity
the total amount of water soil can hold
- water retention contributes to the productivity and fertility of soils
continental vs oceanic crust
- both float on top of mantle
- continental crust is less dense and thicker
- oceanic crust is more dense and thinner
why are plates moving
plates at out planet’s surface move because of the intense heat in the Earth’s core that causes molten rock in the mantle to move
convection cells
- form when warm material rises, cools, and eventually sinks down
- as the cooled material sinks down, it is warmed and rises again
mid oceanic ridge
- seafloor spreads at a great depth of the ocean from a divergent plate boundary
- ex: Mid-Atlantic Ridge
how are mountains made
- mountains are made at convergent plate boundaries where two plates collide
What two plates are grinding together to form the San Andreas fault in California? What type of plate boundary exists here?
The Pacific Plate and the North American Plate. This is a transform plate boundary.
how are island arcs made
An island arc is a chain or group of islands that forms from volcanic activity along a subduction zone. Subduction occurs when oceanic lithosphere sinks underneath continental or
oceanic lithosphere.
soil conservation: contour plowing
Practice of plowing or planting across a slope following its elevation contour lines
soil conservation: windbreaks
- rows of tall trees are used in dense patterns around the farmland and prevent wind erosion
soil conservation: no-till
this is the method of growing crops year round without changing the topography of the soil by tilling or contouring
soil conservation: cover crops
rotated with cash crops in order to blanket the soil all year - round and produce green manure that replenishes nitrogen and other critical nutrients
gases of earth’s atmosphere: N
- 78%
- mostly in the form of N2 (unusable to plants without being fixed)
gases of earth’s atmosphere: O
- 21%
- produced by photosynthesis in plants and needed by humans and animals for respiration
gases of earth’s atmosphere: Ar
- 0.93%
- inert, noble gas
gases of earth’s atmosphere: water vapor
- ~4%
- varies by region and conditions
- acts as a temporary GHG but less concerning than CO2
- quickly cycles through atmosphere
gases of earth’s atmosphere: CO2
- 0.04%
- most important GHG
- leads to global warming
exosphere
- outmost layer where atmosphere merges with space
thermosphere
- therm = hottest temperature
- absorbs harmful x-rays and UV radiation
- charged gas molecules glow under intense solar radiation producing aurora borealis
mesosphere
- meso = middle
- 60-80 km
- even less dense
stratosphere
- ”s” for second
- 16-60 km
- less dense due to less pressure from layers above
- thickest O3 layer is found here; absorbs UV-B and UV-C rays which can mutate DNA
troposphere
- tropo = change (weather occurs here)
- 0-16 km
- most dense due to pressure of other layers above it
- most of atmo. gas molecules are found here
exosphere temp
- temperature increases as you go higher due to absorption of solar radiation
thermosphere temp
- temp increases due to absorption of highly energetic solar radiation
- hottest place on earth
mesosphere temp
- temp decreases because density decreases, leaving fewer molecules to absorb
- coldest place on earth
stratosphere
- temp increases because top layer of stratosphere is warmed by UV rays
troposphere
temp decreases as air gets further from warmth of earths surface
causes of urban heat island
- change in surfaces of urban areas
- waste heat
- population density
atmospheric circulation =
- energy from sunlight
- density properties of air
- rotation of earth (coriolis effect)
air properties
- warm air rises
- warm air holds more moisture than cold
- rising air expands and cools
- cool air can’t hold as much H20 vapor (condenses -> rain)
- after cooling and expanding, air sinks
coriolis effect
- deflection of objects travelling through atm. due to spin of earth
- objects deflect to the right in NH, left in SH
how is wind created
- It is produced by the uneven heating of the earth’s surface by the sun.
how does wind control ocean currents
- surface currents are set in motion by the wind, which drags on the surface of the water as it blows
- the winds pull surface water with them, creating currents
what is a watershed
an area of land that drains all the streams and rainfall to a common outlet such as the outflow of a reservoir, mouth of a bay, or any point along a stream channel
why are watersheds important
- surface water features and storm water runoff within a watershed ultimately drain to other bodies of water
- essential to consider these downstream impacts when developing and implementing water quality protection and restoration actions
insolation
- incoming solar radiation
- measured in watts/m2
solar intensity of insolation depends on
a. angle: how directly rays strike earth’s surface
b. the amount of atmo. suns rays pass through equator is more horizontal
insolation of equator
higher insolation than higher latitudes
what causes seasons
tilt of earths axis
what are equinoxes
- when day and night are of equal lengths
albedo
- the proportion of light that is reflected by a surface
- surfaces with higher albedo reflect more light, and absorb less heat
weather and climate are affected bu
- the suns energy
- geologic and geographic factors such as mountains and ocean temperature
rain shadow
- a region of land that has become drier because a higher elevation area blocks precipitation from reaching the land
windward side
- warm, moist air from ocean hits the “windward” side of the mountain, rises, cools (condensing H2O vapor and causing rain) -> lush, green vegetation
- receives heavy rainfall;
leeward side
- dry air descends down “leeward” side of mountain, warming as it sinks
- leads to arid (dry) desert conditions
example of rain shadow
- Andes Mountains in South America
- eastern trade winds blow moist air from Atlantic across South America
ENSO stands for
el nino-southern oscillation, which occurs in the Pacific Ocean
what is El Nino
- climate pattern that describes the unusual warming of surface waters in the eastern equatorial Pacific Ocean
effects of el nino
- negative impacts off the coast of South America because it stops the upwelling of the cool nutrient rich water which decreases the amount of fish available for catch
- can increase storm systems in South America
- leads to unusually high temperatures and reduced rain fail in Australia
ecological footprint
The impact of human activities measured in terms of the area of biologically productive land and water required to produce the
goods consumed and to assimilate the wastes generated.
