APES Unit 4: Earth Systems

core

dense mass of nickel, iron, and radioactive elements, releases lots of heat

mantle

liquid layer of magma surrounding the core, stays in liquid state because of heat from core

Asthenosphere

solid, flexible, outer layer of mantle

Lithosphere

thin layers of rock floating on top of the mantle, broken up into tectonic plates

crust

outmost layer of lithosphere, the earth’s surface

divergent plate boundary (what are they, what do they form?)

plates move AWAY from each other (diverge), magma plume comes from mantle and pushes plates apart more

they form: volcanoes, mid-oceanic ridges, seafloor spreading, rift valleys

convergent plate boundary (what are they, what do they form?)

plates move TOWARDS each other (converge), lead to subduction

they form: mountains, island arcs, volcanoes

transform fault plate boundary (what are they, what do they form?)

plates SLIDE PAST each other, they lock each other in place, pressure builds up and is released, shaking lithosphere

they form: earthquakes

subduction zones

during convergent plate boundaries, one plate goes under and sinks into the mantle. the other plate goes up and can form things like volcanoes and mountains

convection cycles

earth’s core heats up magma in mantle, causes it to rise up into lithosphere. after it cools down it expands, becomes a new part of the lithosphere, and pushes the tectonic plates apart (divergent plate boundary). this leads to subduction and new land structures being formed

3 types of subduction zones

1. oceanic-oceanic subduction zone:

   • two oceanic plates converge, one slides underneath other

   • magma rises up into lithosphere surface

   • forms: mid-ocean volcanoes

2. oceanic-continental subduction zone:

   • oceanic plate and continental plate converge, oceanic goes under

   • magma rises up into lithosphere surface

   -f orms: coastal mountains, land trenches, volcanoes, an tsunamis

3. continental-continental subduction zone:

   • two continental plates converge, one slides underneath other

   • forces crust upwards

   • forms: mountains

ring of fire

circle of volcanoes around pacific plate

hotspots

places with hot magma rising up into lithosphere

soil

mix of living and geologic components

includes: sand, silt, clay, humus, nutrients, water, air, living organisms

humus

part of soil, made up of decomposing organic material

how does soil help plants?

they anchor the roots into the ground and provide nutrients for the plants

how does soil help water?

filters rainwater, pollutants, the clean water goes through soil and goes into waterways or groundwater

weathering (what is it, and three types)

breaking down of rocks into smaller pieces, adds to soil

physical weathering: physical conditions such as wind and rain

biological weathering: roots of trees crack rocks

chemical weathering: acid rain and acid from moss/lichen

erosion

transport of broken down rocks through rain and wind, fragments are deposited in a new place

deposition

through erosion, rock fragments are DEPOSITED into a new location

soil formation

• large rocks are weathered to tiny pieces and form inorganic parts of soil

• erosion and deposition adds more minerals and rock fragments into soil

• breakdown of organic material adds to humus of soil

topography

how level the ground is in an area

soil horizons

• O-Horizon: topmost layer of soil, contains the organic material of the soil

• A-Horizon: “topsoil,” contains humus and minerals from parent material

• B-Horizon: “subsoil,” mostly minerals, little organic material

soil degradation (what is it + 3 major causes)

in soil, the loss of the ability to support plant life

causes:

• loss of topsoil: tilling (farming technique) and lack of plants increase erosion

• compaction: machines, grazing livestock, and humans compact soil, can’t hold moisture, dry soil

• nutrient depletion: repeatedly growing the same crops in an area over time depletes certain nutrients

soil texture

the percent proportion of silt, sand, and clay

ex: 40-40-20

soil porosity (what is it + different porosities of silt/sand/clay)

the amount of space between the partices/pores of a soil

sand porosity: biggest porosity because biggest particles, high permeability, low holding capacity

silt porosity: medium porosity because medium particles, medium permeability, medium holding capacity

clay porosity: least porosity because smallest particles, low permeability, high holding capacity

what 3 particles make up the geologic portion of soil? (in order of biggest to smallest)

sand > silt > clay

soil permeability

how easily water drains through soil

soil holding capacity

how well soil can retain water

soil fertility (what it is + 2 factors)

the ability of soil to support plant growth

factors:

• enough nutrients

• good amount of soil permeability and holding capacity

gases in the atmosphere (list + percentages)

nitrogen: 78%

oxygen: 21%

water vapor: 0-4%

argon: 0.93%

CO2: 0.04%

layers of the atmosphere (list + desc. + temps)

Exosphere: Outermost layer, merges with space

Thermosphere: hottest temperature on earth, absorbs x-rays and UV rays, northern lights are produced when gas molecules are heated up and glow

Mesosphere: Meso = middle, coldest place on earth because least molecules available to absorb heat

Stratosphere: “S” for second, most O3 here (ozone layer) which absorbs most of the harmful UV rays, temp increases again because warmed by UV rays

Troposphere: Tropo = change (weather occurs here), most gas molecules are found here, temp gets warmer is gets closer to the earth

hadley cells

1. air that gets most direct sunlight gets heated up

2. heated up hair rises, and expands and forms clouds

3. after heat is released, cool dry air comes back down

4. deserts are formed in areas with low humidity in air

coriolis effect (what is it + effects on air in different latitudes)

deflection of objects moving through the atmosphere because the earth spins

air 0-30°: moves west to east since earth rotates east to west

air 30-60°: moves east to west since earth rotates faster at high/low latitudes

global wind patterns (3)

1. air at 30° latitude goes outwards to 60° and 0°

   • high pressure at 30°, low pressures at 60° and 0°

   • high to low pressure

2. air at 0-30° moves E→W due to coriolis effect (eastern trade winds)

   • moves ocean currents east

3. air at 30-60° moves W→E due to coriolis effect (westerlies)

watersheds (what is it + 3 factors)

all of the land that drains into a specific body of water

factors:

• slope: how fast the water moves

• soil composition: how much water is absorbed while going down a watershed

• vegetation: affects how much water is absorbed

solar intensity and latitude

closer to the equator = more solar intensity

• sunlight hits area more direct

• less is deflected by atmosphere

closer to the poles = less solar intensity

• sunlight hits area more spread out

• more is deflected by atmosphere

solar intensity and season

orbit of earth around sun + earth’s tilt causes different insolation in different times during different seasons

insolation

amount of sunlight radiation in a given area

albedo (what is it + examples)

amount of sunlight reflected by a surface

• higher albedo reflects more, abosrbs less (ice/snow)

• lower albedo reflects less, absorbs more (water)

3 main factors of climate

• insolation affects surface temp and precipitation

• mountains disrupt wind and create rain shadow effect

• oceans moderate temperature and humidity

rain shadow effect

• humid warm air comes form ocean and hits windward side of mountain, rises, cools, rains, lush green vegetation.

• dry air descends on leeward side of mountain, creates desert conditions

gyres

large oceanic circular patterns due to wind patterns

upwelling zones

areas of wind blowing surface warm air away from the shore, and deeper, nutrient rich, colder water upwells to replace it

El Nino Southern Oscillation (ENSO) (what is it + steps)

Change in trade winds between Australia/Southeast Asia and South America (SA)

1. trade winds reverse, go W→E

2. warm water goes to SA coast

3. less upwelling in SA coast

4. warmer and more precipitation in SA

5. cooler and drier in Australia/Southeast Asia

Normal wind patterns between Australia and South America

1. trade winds blow torwards Australia

2. blows warm water away from South America

3. Upwelling in south america

4. cooler and drier conditions in south america

5. warmer and wetter conditions in Australia

La Nina

Strengthening of trade winds between Australia/Southeast Asia and South America (SA)

1. trade winds strenghten, keep going east to west

2. extra upwelling in south america

3. extra wet and warm in australia