unit 3 Flashcards
top surface litter layer, decomposed leaves and organic matter, normally brown or black, rich in bacteria, fungi, insects and earthworms
o horizon
topsoil layer, humus and minerals. roots are in this area, also rich in living organisms, if dark brown or black: rich in nitrogen and organic materials, ***if gray/yellow/red: low in organic material, bad for crops
a horizon
subsoil layer, mostly inorganic materials, clay particles, receives material from A horizon through illuviation, may be colored by iron oxides (red), aluminum oxides (yellow), or white due to calcium carbonate, leaching, lots of humus
b horizon
weathered parent material, consists of broken fragments of parent rock, caco3 and mgco3 accumulates here forming a hard impenetrable layer
c horizon
breaks rocks into smaller pieces (water, machinery, wind, etc)
mechanical weathering
change mineral makeup of a rock, chemical reactions between minerals in the rock and the environment
chemical weathering
both mechanical/chemical in some ways, but always involves living organisms (ex: lichen secrete acids into rocks that break down its minerals)
biological weathering
diameter greater than 0.05 mm, high permeability, poor water capacity, poor nutrient capacity, good aeration, good workability, low porosity (cannot hold water)
sand
between 0.002 and 0.05 mm, medium levels of all characteristics
silt
less than 0.002 mm, low permeability, good h20 capacity, good nutrient capacity, poor aeration, poor workability, high porosity
clay
relatively equal portions of sand, silt, clay (ideal soil for farming)
loam
the degree to which soil resists pressure; important when considering how land should be managed
soil consistence
mass/volume, expresses how much soil weights per unit volume depending on amount of pore space and density of soil particles
bulk density
reduces permeability of soil to water and air, if soil is subjected to pressure, pore spaces can collapse, decreasing pore space
compaction
can help determine whether a piece of land should be planted w/ grass, trees, etc., or if it can be used for homes, lots, landfills, septic tanks, etc.
slope of the land
presence of gullies, examination of surfaces of soil
signs of erosion
character and chem. composition directly impacts soil chemistry and properties (ex: coarse grained parent material=coarse grained texture soil)
parent material
content of soil (clay, silt, sand)
soil texture
how particles are organized/clumped
soil structure
water holding capacity, very porous soil has more spaces, and can hold more water
porosity
rate of percolation, related to porosity
permebility
ability of air to move through soil
aeration
magma cools and solidifies, bulk of crust (ex: granite)
igneous rock
sediments “cement” under pressure, weathering forms sediment (ex: contains fossils)
sedimentary rock
preexisting rock transformed-heat and pressure
metamorphic rock
rocks turn into soil by weathering formation and change in soil over time
soil development
- weather is experienced
- 0-15 km up in the air
- temperature drops as you go up
troposphere
cool air on top, warm air on bottom
normal air conditions
cold air is heavier, trapping pollutants
temperature inversion
- 25% or less cloud cover
- light and variable winds (especially below 3mph)
- dry soil surface
- low elevation areas such as valleys and basins where cool air can sink and collect- inversions will begin sooner, last longer, and be more intense in these areas
conditions that favor temperature inversions
- above troposphere
- 10-50 km up
- increase in temperature (ozone layer!)
- contains stratospheric zone
stratosphere
main function being to absorb UV rays produced from the sun (shield effect)
purple = low 03
green= high 03
the ozone layer
- above stratosphere
- COLDEST LAYER
- 50-80 km up
- temperatures fall as you go up
mesosphere
- 80-480 km up
- as you go up, temperatures rise
thermosphere
Found in b/t layers; temps are constant
pauses
b/t troposphere and stratosphere (jet stream)
tropopause
More direct radiation at equator 🡪 heats up air.
Heated air travels north and cools 🡪 descends (density differences). Hadley Cell
Creates wind currents.
solar radiation
force exerted on a unit of area
Movement of air from high (warm air) to low pressure areas (cold air) 🡪 wind.
Winds move water and air!
air pressure
- coriolis effect (earth’s rotation)
- objects are deflected
- North Hemisphere= right of the equator
- South Hemisphere= left of the equator
wind and ocean current direction is affected by…
Trade winds relax 🡪 doesn’t move H2O West Pacific 🡪 Warm H2O accumulates in So. America
3-8 yrs. during winter
el nino
Decline of upwelling which brings nutrients to surface 🡪 Death/movement of orgs in ocean.
- in california, migration/death of orgs due to warmer water, storms in east pacific, lots of rain (hotter water)
- in south america, Massive floods, mud slides, Fisheries collapse (little upwelling) 🡪 lack of nutrients, Typhoons, Coral Bleaching (Sensitive to Heat)
- in australia, EXTREME drought, dust storms, fires
effects of el nino
Opposite of El Niño: Cold air oscillations
Usually happen after an El Niño year; water is really cold in east Pacific and needs to be reheated.
Unusually cold ocean temps in Eastern Eq. Pacific
effects of la nina
climate is largely determined by…
insolation (latitude → angle of insolation & atmosphere)
Higher latitudes receive less insolation: cooler, less precipitation (especially at 30 degrees latitude)
Equator receives most intense insolation: higher temp, air rises, higher precipitation
Mountains– disrupt wind and produce the rain shadow effect
Ocean–moderate temperature and add moisture to the air
geography’s role
Dry air descends down “leeward” side of mtn, warming as it sinks
Leads to arid (dry) desert conditions
rain shadows
windward–> way wind is coming from
leeward–> way wind is going
hadley cells
low-latitude overturning circulations that have air rising at the equator and air sinking at roughly 30° latitude. They are responsible for the trade winds in the Tropics and control low-latitude weather patterns
Will have many nutrients
Takes 100-1000 yrs to form.
fertile soil
Measure of spaces per volume of soil 🡪 holds more H2O/air
porosity
how fast H2O/air move down in soil.
permeability
Prod. a lot of food!
Lots of fossil fuels, water, commercial inorganic fertilizers and pesticides used.
Makes 1 type of food (monoculture).
high input farming/tillage (but it destroys the soil!!)
Reduces irrigation & pesticide use
Uses organic fertilizers.
Soil conservation techs.
Less food
sustainable and low input agriculture
Low Input Farm
No inorganic fertilizers or chem. pesticides used
No GMOs
organi
slope converted into broad terraces to retain H2O and soi
terracing (soil conservation techs)
c f
plowing and planting in rows across slope of land (slow water and soil runoff)
contour farming
Plant a row of 1 type of plant, then plant a row of another type of plant.
strip cropping
slows wind down before it hits farm soil.
wind breaks
High amounts of NO3, NH4, and PO4. Easily transported, stored, and applied.
Do not add humus, release NOx (greenhouse gas) when applied, eutrophication in streams.
inorganic fertilizers
1) Animal manure: dung/urine of animals
2) Green manure: plants plowed into soil
3) Compost: semi-broken down org. matter
organic fertilizers
Lower fuel emissions of greenhouse gases
Less gas used
Less transport of pests
Less packaging
Lower costs of produce
Revenues remain local
perks of farmers’ markets
