ap environmental science unit 4 (plate tectonics, ENSO/la niña, coriolis effect, wind patterns, weather, thermohaline circulation, soil, watersheds)

unit 4 APES review with detailed but concise explanations of plate tectonics, ENSO/la niña, coriolis effect, wind patterns, weather, thermohaline circulation, soil, and watersheds. information directly from my APES teacher or mr. smedes :)

earth’s core

• it is hot because of radioactive deacy

• the most abundant metal at the core is iron

• there is a solid inner core and a liquid outer core

order of earth’s layers

solid inner core —> liquid outer core —> mantle —> crust —> lithosphere

subduction zone

a subduction zone is when…

• an oceanic plate which is denser, pushes beneath a less dense continental plate

• the sinking oceanic plate is melted and magma rises up to the surface through the cracks in the zone. this forms a volcano

earthquakes along subduction zones release a lot energy

if they happens in the ocean…

• it will cause a tsunami

the theory of plate tectonics

the lithosphere is divided into plates which are in constant motion

divergent plate boundaries

these occurs when plates move away from each other. these boundaries form rift valleys

common locations of divergent plate boundaries are: east african great rift valley, mid-atlantic ridge

convergent boundaries

occur when plates move towards each other

oceanic & continental

they form a volcano and trench along the subduction zone

common location: between the Nazca Plate and South American Plate

oceanic & oceanic

both of them push up and form trenches alongside, causing an undersea volcano to form and which eventually rises above sea-level and forms an island usually part of an island arc

common location: Pacific Plate south of Alaska (forms Aleutian Islands)

continental & continental

they both push up and form mountains

common location: the Himalayas in India

transform fault

the plates slide past each other

common location: San Andreas Fault (on west coast of California)

impacts of volcanoes

mostly negative:

• they cause habitat destruction which disrupts the food web and leads to decreased biodiversity

• habitat fragmentation disrupts the gene flow and leads to decreased biodiversity

• ash and soot cause decreased visibility and respiratory diseases

• sulfur emissions can cause acid rain which can decrease pH and kill low tolerance organisms which disrupts the food web and leads to a decrease in biodiversity

however one positive impacts is:

• the weathering of lava leads to fertile soil

convergent earthquakes

plates suddenly collide

divergent earthquakes

plates suddenly move apart

transform earthquakes

plates slide past each other rapidly

how do you read a soil diagram?

you first read clay from the left, then sand from the bottom and lastly, silt from the right

physical weathering

rain, wind, waves

chemical weathering

oxidation, acid rain, lichen

biological weathering

plant roots, bacteria that produce organic acids

o horizon

organic matter or humus made up of mostly dry leaves. it is what is left over after the decomposition process done by worms, fungi, or bacteria.

a horizon

the topsoil or the mineral layer with a defined structure

b horizon

the subsoil with accumulated compounds leached from the a horizon

c horizon

made up of unconsolidated parent material such as weathered bed rock

what are the key functions of soil?

• soil provides nutrients (NPK) and anchorage for plants

• soil helps transform and decompose certain harmful chemicals and contaminants and filter them out from water

• soil forms a habitat. plants depend on soil for water and nutrients and additionally many microorganisms like fungi and worms live in soil

troposphere

the uneven heating of the regions in the troposphere by the sun causes convection currents (hadley cells, ect.) those wind patterns move heat and moisture around the globe. this is the layer we live in.

stratosphere

the stratosphere is where the ozone layer is found which absorbs protects us from the ultraviolet radiation of the sun

thermosphere

auroras occur there because solar particles trapped there interact with oxygen and nitrogen resulting in colored displays of light

hadley cell

1) warm water evaporates and moves upwards because of its density

2)it undergoes adiabatic cooling and when it moves up it loses energy and slows down to condense which then forms clouds and eventually it rains

3) precipitation/condensation releases energy which results in latent heat release, an exothermic reaction

4) the now cold and dry air moves north and south

5) as the air gets closer to the earth, adiabatic heating occurs because of increases in pressure and the air warms again

because of this 30 degrees is usually dry hot air

coriolis effect

because of the earth’s rotation, circulating air is deflected to the right in the north and the left in the south

rain shadow effect

the cold arid air rises over a mountain it warms and dries when descending on the leeward side causing dry hot air and desert like conditions

the oceans role in weather

coastal weather tends to be more moderate because the ocean warms and cools more slowly than the atmosphere

evaporation

evaporation from the ocean (especially from the tropics) creates the most rain clouds which influences the blocations of wet and dry zones

westerlies and easterlies

westerlies are:

• wind moving from west to east

• latitude 30-60 north and south

easterlies are:

• wind moving from east to west

• latitude 0-30 north and south

normal conditions

• wind is going towards the equator from east to west

• cold water along the west coast of South America

• the wind blows hot water from the surface allowing upwelling to take place

• precipitation is good in Australia and it is decently dry in South America

el niño (el niño souther oscillation, ENSO)

• wind is flowing west to east

• more hot water is being pushed towards South America which leads to a decrease in upwelling and more pooling of warm water

• South America is wet and flooding while Australia is hot and dry usually causing forest/wild fires

la niña

• an exaggeration of normal conditions

• South america is drier than usual

• more precipitation in in Australia which causes flooding

insolation

incoming solar radiation

• insolation = solar radiation/area

• the surface most perpendicular will have the highest concentration of solar radiation

• the angle of incidence decreases moving towards the poles which increases the area of incidence, forcing insolation to decrease

fall equinox

september 22=23

spring equinox

march 20-21

summer solstice

june 20-22

winter solstice

december 21-22

thermohaline circulation

• how differences in temperature and salt concentration push water down

• thermohaline circulation helps spread heat from equator resulting in only a 30 degree difference from the poles

meridional overturning circulation

ocean currents that bring warm water north and cold water south

watersheds

the area of land water flows through

human impacts on watersheds

impacts:

• building dams and rerouting rivers

• land decomposition exacerbated by deforestation and its debris ends up in bodies of water

• urbanization makes it so there are less pervious surfaces which means an increase in flooding and also unfiltered runoff which redirects polluted and contaminated water in the the watersheds

solutions to human impacts

solutions:

• more pervious surfaces (pervious pavers, etc.)

• water conservation

• proper disposal of chemicals

• less use of toxic pesticides and fertilizers

albedo effect

the ability of surfaces to reflect the sun

• tree cover helps limit the albedo effect causing less evaporation of water