APES Unit 4 Flashcards
what is soil?
a mix of geological and organic components
soil components
⇨ sand, silt, clay
⇨ humus - main organic part of soil
⇨ nutrients - ammonia, nitrate, phosphates, etc.
⇨ water and air
⇨ living organisms - bacteria, worms, fungi
why is soil important?
⇨ medium for plant growth
⇨ carbon storage
⇨ filters water
⇨ habitat for organisms
⇨ breaks down organic material and recycled nutrients.
weathering
How?
breaking down of rocks into smaller pieces
- physical (wind, rain)
- biological (roots of trees)
- chemical (acid rain, moss, lichen)
erosion
transport of weathered rock fragments by wind, rain carried to new location and deposited.
soil formation from below
weathering of parent material produces smaller fragments that make up geological part of soil (sand, silt clay, minerals)
soil formation from above
⇨ breakdown of organic matter
⇨ erosion deposits soil particles from other areas.
effects on soil formation
parent material
topography
climate
organisms
effects on soil formation parent material
soil pH, nutrient content
effects on soil formation topography
steep slope = too much erosion
more level ground = deposition
effects on soil formation climate
warmer = faster breakdown of organic matter
more precipitation = more weathering, erosion and deposition
effects on soil formation organisms
soil organisms like bacteria, fungi, worms break down organic matter and mix up the soil
soil horizons O layer
Organic layer is layer of organic matter on top of soil provided nutrients and limits H2O loss
soil horizons A layer
top soil is a layer of humus and minerals with the most biological activity
soil horizons b layer
sub soil is lighter layer below topsoil, mostly sand, silt and clay some nutrients
soil horizons c layer
substratum is least weathered soil, composed of rock fragments no organic material
Soil degradation
the loss of the ability to support plant growth
loss of topsoil
tilling (turning soil) & loss of vegetation disturb soil and make it more easily eroded
loss of topsoil dries out soil, removes nutrients and soil organisms that recycle nutrients
compaction
compression of soil by machines (tractors) grazing, lifestock (cows), and humus reduces ability to hold moisture
- dry soil erodes more easily
- dry soil supports less plant growth, less root structure, leading to more erosion
nutrient depletion
repeadingly growing the same crops on the same soil removes key nutrients (N, P, K, Na, Mg) over time
- reduces ability to grow future crops
soil particles
geological portion of soil biggest to smalles
sand>silt>clay
soil texture
the % of sand silt and clay in soil
always adds up to 100% EX 40-40-20 = 40 sand 40 silt 40 clay
less compact soil vs compact soil
sand is bigger it has bigger pores (less compact) this allows water and air to eneter soil easily
clay has smallest pores wo its harder for air and water to enter heavy clay soils
porosity
the pore space within a soil
permeability
how easily water drains through
- more porosity = high permeability
H2O holding capacity
how well water is held
more porosity = low water holding Capacity
inverse relationship between porosity/permeability and H2O holding capacity
what is ideal soil for most plants
loam
soil fertility
abilty of soil to support plant growth
soil fertility nutrients
N, P, K, Mg, Ca, Na (all positively charged)
to increases nutrients soil fertility
- organic matter, humus
- decomposer activity
- clay
clay particles are negatively charged and are atracted to positve nutrients - bases pH >7 means there is less hydrogen (positively charged) to displace nutrients
to decrease nutrients soil fertility
- acids pH< 7 hydrogen displaces nutrients
- excessive rain drains nutrients
- excessive farming
to increases water holding capacity soil fertility
- derated soil (biological activity)
- compost/humus/organic matter
- clay content
- root structure (allows there to be gaps and spaces between soil particles therefore storing more water)
Decrease water holding capacity soil fertility
- compact soil (cows, machines)
- top soil erosion (contains humus)
- sand
- root loss
core
dense mass of solid (inner) and liquid (outer) iron, nickel and radioactive elements that release lots of heat
mantle
solid/ semi solid layer of rock/ magma surrounding core, kept malleable from imense heat form core
asthenosphere
softer layer of mantle, high pressure/ temp lead to magma
lithosphere
thin, brittle layer of rocks that includes solid upper mantle and crust (tectonic plates)
crust
very outer layer of lithosphere, earth’s surface
divergent plate boundary
-plates move away from each other
- forms mid oceanic ridges, volcanoes, seafloor spreading, rift valleys and earthquakes
convergent plate boundary
- plates move towards each other
- leads to subduction
subduction
one plate being forced beneath the other
- forms mountains, island arcs, earthquakes, volcanoes
transform fault plate boundary
- plates slide past each other in opposite directions
- forms earthquakes
transform fault boundary (step by step)
- plates sliding past each other in opposite directions creates a fault
– earthquakes = most common
– occurs when rough edges of plates get stuck on each other
– pressure builds as plates keep sliding but edges stay stuck
– when stress overcomes the locked fault, plates suddenly release, slide past each other and release energy that shakes the lithosphere.
ring of fire
pattern of volcanoes & earthquakes all around pacific plate
– offshore island arcs (japan)
transform faults
likely location of earthquakes
hot spots
areas of especially hot magma rising up to lithosphere.
- mid oceanic islands (Iceland, Hawaii)
convergent boundary - oceanic - oceanic
- forces magma up to lithosphere surface, forming mid ocean volcanoes
convergent boundary- oceanic-continental
dense oceanic plate subducts beneath continental & melts back into magma.
- forces magma up to lithosphere surface
- coastal mountains, volcanoes, tsunamis, trenches
convergent boundaries - continental continental
one plate subducts underneath other, forcing surface crust upward
- forms mountains.
convection cycle (divergent)
- magma heated by earths’ core rises towards lithosphere
- rising magma cools & expands forcing oceanic plates apart
- magma cools and solidifies into new lithosphere
- spreading magma forces oceanic plates into continent
- sinking oceanic plates melts back into magma
- also forces magma up, creating narrow coastal mountains & volcanoes on land.
atmospheric circulation due to
- most solar radiation at equator
- density properties of air
- rotation of earth (Coriolis effect)
air properties
- warm air is less dense and rises
- warm air holds more moisture
- cold air is more dense and sinks
Hadley cell
- more direct sunlight at equator causing warm air and lots of evaporation
- warm, moist air rises and as it rises it loosed moisture and heat. Moisture than rains back down over the equator. and air continues to rise
- as air cool and hits the Tropopause, it spreads.
- cool, dry air sinks over about 30° N and 30°S
- leaving air causes a vacuum which sucks cold air back into the middle over the equator.
low and high pressure along lattitude lines
always switching
Low pressure at 0°
high at 30° N and S
low pressure at 60° N and S
ferell cells
-happen at 30°-60°
-travel opposite direction as hadley cells but same concept
-air travels down at 30°
coriolis effect
deflection of objects traveling through atmosphere due to spin of the earth
earth spinning factors
1.earth is spinning fastest at widest point (equator) because it has to spin a further distance in the same amount of time as For example the poles
2. earth spins from West to East
how is wind deflected?
– wind traveling towards the equator (0°-30°) (from slower to faster) is deflected to the west
– wind between 30°-60° is deflected to the east
global wind patterns between 0° - 30°
0°-30° wind blow East to West
– Eastern trade winds
– drives ocean current clockwise in N hemisphere and counterclockwise in S hemisphere
global wind patterns between 30° - 60°
30°-60° wind blow West to East
– westerlies
– drives weather patterns of North America
gasses in earths atmosphere
nitrogen - 78%
oxygen - 21%
argon - 0.93%
water vapor - 0-4%
C02 - 0.04%
troposphere
weather occurs here most dense due to gravity
– most of atm’s gas molecules here
– ozone in troposphere is harmful to humans
stratosphere
less dense
– ozone layer is found here absorbs UV rays which damage DNA and cause cancer
mesosphere
even less dense
– meteors encounter friction
thermosphere
hottest layer
– absorbs harmful X-rays and UV radiation
– charged gas molecules glow under intense solar radiation causes aurora borealis
exosphere
outermost layer where atmosphere meets space
what is it called where layers meet?
a pause
EX Tropopause
order of layers of atmosphere
Troposphere
stratosphere
mesosphere
thermosphere
exosphere
temperature gradient troposphere
troposphere – temperature decreases as air gets further away from warmth of earths surface
temperature gradient stratosphere
temperatures increases due to ozone layer absorbing UV radiation formation of ozone from 02 releases heat
temperature gradient mesosphere
temperature decrease because density decreases leaving less molecules to absorb sun
temperature gradient thermosphere
temperature increases due to absorption of highly energetic solar radiation
watersheds
all the land that drains into a specific body of water
what are watersheds determined by
slope
–greater slope = faster velocity of runoff & more soil erosion
vegetation
– more vegetation = more infiltration
permeability determines runoff vs. infiltration rates
human activity within a watershed that impact water quality
agriculture, clearcutting, urbanization, dams
chesapeake bay watershed
-Drains into a series of streams and rivers & eventually chesapeake bay
-estuary that is being heavily polluted
- estuaries and wetlands provide ecosystem services
human impacts on watersheds Nutrient pollution
nutrient pollution (N & P) leads to eutrophication in bay
Major N and P sources
1) discharge from sewage treatment plants
2) animal waste from CAFOS
3) synthetic fertilizer from agricultural fields
human impacts on watersheds sediment pollution
sediment pollution is due to deforestation, urbanization and tilling of agricultural fields
– incr. turbidity & covers rocky stream bed habitats
– reduced sunlight / photosynthesis
– animals covered by sediment may suffocate/ can’t see
direct affets of clear cutting
soil erosion
– caused by loss of stabilizing root structure
– removes soil organic matter & nutrients from forest
– deposits sediments in local streams which warms up water temp and makes it more turbit
increase water temp due to…
deposited sediments in streams
loss of tree shade incr. soil and water temp.
insolation
the amount of incoming solar radiation (energy from sun’s rays) reacting on area measured in Watts/m2
turbidity
how cloudy and dusty the water is
solar intensity and lattitude depends on
–the angle how directly rays strike earths surface
– the amount of atmosphere rays pass through
where on earth is the highest insolation
at the equator because sun’s rays hit at 90 degrees perpendicular
polar day vs polar night
polar day is when there is 24 hour light
polar night is when there is 24 h darkness
when polar day in North, polar night in South
what causes seasons on earth’s surface
the orbit and tilt of earth causes some areas of the earth to be further or closer to the sun, changing the seasons
Solstices
June and December: N and S hemisphere are maximally tilted toward the sun (summer and winter)
equinox
March and September: N and S hemisphere are equally facing the sun (spring and fall)
albedo
the amount of light that is reflected by a surface
what affects albedo
color plays a large role
surface with high albedo reflect more light and have a lower temperature
urban heat island
urban areas are hotter than surrounding rural areas due to low albedo of blacktop
climate is largely determined by insolation
higher altitudes recieve less insolation: cooler, less precipitation especially at 30degrees
equator recieves most intense insolation: higher temp, air rises high precipitation
geography also determines climate
mountains disrupt wind and produce rain shadow effect
oceans moderate temp and add moisture to air
rain shadow effect
– warm moist air from ocean hits the windward side of mountain, rises and cools condensing H20 vapor and causing rain (leads to lush vegetation)
– dry air descends down leeward side of mountain warming as it sinks (leads to arid conditions)
ex Andes mountains
gyres
large ocean circulation patterns due to global wind clockwise in N and anticlockwise in S
upwelling zones
areas of ocean where winds blow warm surface water away from land mass, drawing up colder water to replace it
productive fishing
thermohaline circulation
connects all of world’s oceans mixing salt, nutrients and temperature throughout
1. warm water from gulf of mexico moves toward north pole
2. cools and evaporates as it moves toward poles
3. saltier and colder water @ poles sinks because its denser
4. spreads along ocean floor
5. rises back up into shallow warm ocean current at upwelling zones
El nino southern oscillation
enso: pattern of shifting atmospheric pressure and ocean temp in the equatorial pacific ocean. oscilate regularly from el nino (warmer rainier) to la nina (cooler drier) conditions
effect of la nina
–stronger upwelling and better fisheries in S america
– worse tornado activity in US and hurricane in atlanctic
– cooler drier weather in americas
– rainier warmer incr. monsoon in SE asia
– stronger than usual trade winds
– incr. upwelling in south america
– warmer rainier than normall in SE asia
normal year conditions
– trade winds blow equatorial water E to West
– warm equatorial current brings heat and precipitation to SE asia
– high pressure in east pacific
– low pressure in west pacific
el nino year conditions
– trade winds weaken or reverse W to East
– warm equatorial current brings heat to americas
– cooler, drier conditions in SE asia
– high pressure in west pacific
– low pressure in east pacific
–suppressed upwelling in south america
–warmer winter in N america
– incr. precipitation in americas
– drought in SE asia
–decr. hurricane activity in atlantic ocean
–weakened monsoon in india and SE asia
