UNIT 4, APES, Leake
soil texture is determined by
The percentages of sand, silt, and clay in comparison to each other; clay is tan, smooth usually top, silt is brown and uniform; sand is course
rock cycle
erosion (sedimentary), melting (igneous), and metamorphism (metamorphic); rocks are broken down, melted, and fused together into new forms through heat and pressure, cooling, and sometimes recrystallizing with the earth's crust; slowest of earth cycles and plays a huge role in forming deposits of nonrenewable resources.
porosity
how quickly soil drains; clay drains poorest; sandy soils drain best
insolation is
incoming solar radiation; plays a part in the heating and cooling of earth
Sand
largest particles, lots of air, low water holding ability; good for drainage; high porosity
3 factors determining average temp. and precipitation
latitude and elevation, air and water movement, and solar light
thermocline
layer between warm and cold water, where the temp changes rapidly
confined aquifer
layers of impermeable material are both above and below the aquifer, causing it to be under pressure. Water will rise to top when penetrated; does not get polluted easily, but you must protect it.
crust of continental plates is _________ and rich in ______
less dense; silicon dioxide
East US precipitation
lots of rain compared to west; challenges: flooding and pollution; benefits: energy production, cooling, and manufacturing
sedimentary rocks
made of sediments (dead plant and animal remain and tiny particles of eroded rocks); ex. sandstone, shale, limestone.
core
made up of nickel and some iron; inner is solid; outer liquid
Wind
major role in the redistribution of heat and produces ocean currents; prevailing winds are caused by the rotation of Earth deflecting wind off to the east or west; equator spins faster
sun rays strike directly twice
march and september equinox
base saturation
measure of the proportion of soil bases to soil acids; percentage
mantel
mostly solid and rigid; ASTHENOSPHERE- zone of hot semi-molten pliable rock
H-pressure zones
next to L; warm and cry bc no moisture left.
El Niño year (hot-tempered boy)
no upwelling and flat/reversed thermocline; trade winds weaken (or even reverse); there is no upwelling to replace warm westward moving water w/ cool water; the warm water stays and blows East inland; this brings heavy storms to South America (flips).
ionosphere
not a distinct layer; region where electrons have been knocked from their parent atoms; electrically charges atoms; enables radio communications.
subduction
occurs at convergent boundaries where an oceanic plate slide underneath a continental plate
Soil bases
promote plant growth and are essential (calcium, magnesium, and potassium)
why do earth's outer core and mantel have high temps
radioactive decay of various isotopes, releasing heat (potassium, uranium, thorium)
insolation in tropics
rays travel shorter distance; most direct solar radiation; high insolation
insolation in equator
receives the most solar radiation
thermohaline circulation
responsible for mixing surface and deep water due to high salt concentration (salt water is more dense); influences ocean currents
difference between granites and basalts
silica content and their rates of cooling: basalt is about 53% SiO2 while granite is 73%.
clay
smallest particles; poor drainage; very good Cation exchange capacity
Troposphere
sphere where weather occurs, 99% of water vapor is here (gravity brings gases down); as you get higher it gets colder
L-pressure zones
storms, rainforest; very moist with lots of rainfall
upwelling
strong trade winds whip up cool, nutrient rich water; fish like to come to this zone
tectonic cycle
sum of the processes that build up and break down the lithosphere
insolation in mid-latitude and polar
sun strikes at oblique angle causing it to spread out and be less intense
mesosphere
temperature gets colder as you go higher; coldest temps in the atmosphere; air is too thin to breathe; very low air pressure
thermosphere
temperature gets warmer as you go higher; has the aurora (northern and southern lights)
Cation exchange capacity (CEC)
the ability of soil to absorb and release cations(positively charges mineral ions that may be nutrients for plants); high CEC is associated with clay soil and is desirable for agriculture
Earth's albedo
the ability to reflect solar radiation (some parts of earth reflect solar energy more than others- about 30%, clouds 90% and ice 90%)
aquifers
the deep underground porous layers of sand, gravel, rock, and caverns that water flows through; store water (groundwater); naturally recharged by precipitation; lateral recharge by nearby streams.
what causes the slow motion of tectonic plates
the heat from the core created CONVECTION CELLS which drives the renewal of components of the lithosphere; large volumes of rock and heat are moving
adiabatic heating
the heating effect of increased pressure on air as it heats up, shrinks, and sinks toward the surface of Earth
the finer the texture...
the more difficult a soil is to work or till, the grater the water holding capacity, the slower water drains; more difficult plant root penetration; more readily surface soil will crust; more nutrient rich the soil
surface water
the runoff that gathers and runs into streams, lakes, etc; drains into a watershed (land where water is shedding) or a basin (any water that falls will go here).
what causes seasons
the tilt of earth's axis and the number of hours of daylight
water table
top of the saturated zone; falls in dry weather or when used faster than can be replenished; water here is still percolation through the horizons.
O horizon
top; organic matter; organic detritus; organic horizon; leaf litter and decaying plant material
A horizon
topsoil; organic mixed w/ inorganic; best soil; composed of humus (decomposed organic matter)
Normal year
trade winds roll around equator blows across the water, pushing warm water to the other side of the ocean around Asia; low pressure, storms in western pacific; high winds whip up nutrient rich, cold water from deeper water; upwelling occurs and thermocline is tilted up
lowest to highest layers of atmosphere
troposphere, stratosphere, mesosphere, thermosphere, exosphere
West US precipitation
very low precipitation, high evaporation, drought; 50% of water comes from groundwater withdrawal; share water hot spots, but water is scarce
exosphere
very space-like; air that is present escapes into space; no clear boundary
Convection is when
warm air rises(less dense) and cold air sinks(more dense); called Hadley/Farrell and Polar
unconfined aquifer
water table; able to rise and fall; impacted by drought sooner; get polluted easier, but are easier to wash out; pump, bc of low pressure.
surface runoff
water that does not infiltrate the ground or evaporate
adiabatic cooling
when the rising air meets the lower pressure of higher altitudes, it expands and cools. Now that is is cool and dense, it sinks to high pressure zone.
convergent plate boundary
where plates are pushed together (density rules); b/w ocean and continental, the oceanic is subducted, forming trenches. ex. Mariana's trench); when 2 continental's are pushed together, mountains are formed.
divergent plate boundary
where plates separate; in oceanic plates it is seafloor spreading; magma flows up through these cracks, forming ridges. ex. mid-Atlantic ridge; continental- huge separation; like a canyon; ex. African rift valley
transform fault
where plates slide past one another (side by side) in opposite directions)
When is the Earth closest to the Sun?
winter
lithosphere
crust and upper mantle
5 factors determining the properties of soils
1. parent material- the rock material underlying soil from which its inorganic components are derived 2. climate- soil doesn't develop well in freezing temps, but occurs rapidly in the tropics (decomposition and water flow are slow, but in tropics, there is high water flow) 3. topography- surface slope; erosion at higher elevation, and deep soils at the base of steep slopes; layers at bottom of slope may be different than those at the top 4. organisms- plants can add or remove nutrients from soil and excrete acids that aid in weathering; burrowing animals mix the soil uniformly. 5. time- old soils have has continual inputs of organic matter and are very fertile; old soils are more complex.
4 factors determining how air circulates and helps distribute heat and moisture
1. uneven heating of earth's surface. 2. rotation of earth's tilted axis. 3. variations in properties air, (convection currents- warm air rises and cold air sinks), water (lends to moisture and air- warm air holds more vapor), and land (vegetation adds moisture and cools by removing CO2). 4. ocean and wind currents.
reliable runoff
1/3 of total; 2/3 lost annually to floods
what latitudes have high pressure
30
Deserts are located at
30º North latitude and 30º South latitude, where heated equatorial air begins to descend, which evaporated water from the surface.
what latitudes have low pressure and colder
60
what is runoff mostly used for
70% AGRICULTURE; 20% industrial; 10% domestic
What percent of earth is water
71%, but only 0.024% is freshwater
physical biological weathering
Biotic weathering is the weakening and subsequent disintegration of rock by plants, animals, and microbes. For example, rabbits and other burrowing animals can burrow into a crack in a rock, which makes it bigger and splits the rock. Also, sometimes weeds grow in cracks in the pavement.
equator pressure
Due to sinking air that cooled off as it moved away from the equator; the equator has low pressure bc all of the warm air is rising and moving away
chemical biological weathering
In this type of weathering, living organisms contribute through their organic compounds that contain molecules that acidify and corrode rock minerals. Ex. Dissolution, causes rocks and minerals to break down to form soil; rust, dissolves rocks
rain shadow effect
MOUNTAINS; prevailing winds pick up moisture from an ocean; air hits the windward side (gets lots of rain and wind; lush), air rises, cools, and releases moisture; then, on the leeward side (dry, very little rain) air descends, warms, and releases little moisture. ex. Death Valley
Soil horizon order
O, E, A (e and a could flip), B, C, bedrock
largest aquifer in the US
Ogallala Aquifer (high overdraft)
zone of saturation
a certain depth below the earth's surface where water completely fills the spaces between rock and gravel
Global ocean currents
affect regional climates; warm and cold currents created by different water densities; altered by earth's rotation and continents; redistributes heat, mixes ocean water, and distributes nutrients and oxygen.
6 giant convection cells caused by
air convection, prevailing winds, and a mixture of continents and oceans.
Coriolis effect
any deflection due to the earth's rotation
floodplains
areas around rivers that hold and absorb flood water; highly productive wetlands, provide natural flood and erosion control, maintain high water quality, and recharge groundwater
global warming
average temp of earth is increasing; may cause changes in the climate in various places; mostly because greenhouse gases trap heat (CO2, methane, nitrous oxide, water vapor); effects: alter precipitation patters, sea levels, and crop growing areas.
Climate is determined by
average temperature and precipitation
loam
best soil for agriculture; mostly humus; 40-40-20 SAND, SILT, CLAY
C horizon
chunks of rock; similar to parent material; least weathered
hydrolic cycle
collects, purifies, recycles, and distributes the earth's fixed supply of water
B horizon
composed of primarily mineral material; small, most weathered rock
mountains
convergent plate boundaries of 2 continental plates
trenches
convergent plate boundary of one oceanic and one continental; subduction
crust of oceanic plates is ______ and rich in _____
dense; iron
ridges
divergent oceanic plate boundaries
La Niña year (cold-natured girl)
follows El Niño; colder than normal conditions in the equatorial pacific ocean; abnormal cooling effect; trade winds are even stronger than usual, causing more than the usual amount of warm water to move away from the Americas; causes larger upwelling, which contributes to the cooling effect of waters; brings up tons of fish; wetter than normal conditions to. east coast of continents.
igneous rock
forms below or on the earth's surface under intense heat and pressure when magma wells up from earth's mantle and then cools and hardens; the majority of earth's crust, but usually covered with sedimentary; ex. granite and lava rock.
metamorphic rock
forms when an existing rock is subjected to high temps (may melt partially), high pressures, chemically active fluids, or a combination of these agents. ex. slate and marble
E horizon
found in acidic rocks; where leaching occurs; living organisms
what three groups account for 80-90% of the biological activity in soils
fungi, bacteria, and protozoans; majority of soil organisms are detritivores
stratosphere
gets warmer as you go up; the jet stream flows near the border; OZONE layer is found here
Texture of soils
gritty- has a lot of sand sticky- lot of clay, retains a lot of water crumbly/spongy- soil is heavily loam
groundwater overdraft
groundwater exceeds the amount of recharge in an aquifer, which leads to a decline in groundwater level.
acidic soil
harmful to plant growth (aluminum and hydrogen); lime may be added to adjust pH
crust
outermost and thinnest; continental crust and oceanic basins
silt
particles larger than clay, but smaller than sand; drains slowly
Soil is the result of
physical and chemical weathering of rocks (inorganic) and the gradual accumulation of detritus from the biosphere (organic)
hot spots
places where magma wells upward from the mantle and reachers the lithosphere (crust and mantle)