unit 4 (earth systems and resources)

the layers of earth

core, mantle, asthenosphere, lithosphere, and crust

core

a dense mass of solid nickel, iron, and radioactive elements that release massive amounts of heat

mantle

a liquid layer of magma surrounding the core, and it is kept liquified by the intense heat from core

asthenosphere

a solid, flexible outer layer of the mantle, just beneath the lithosphere

lithosphere

a thin, brittle layer of rock floating on top of the mantle, and it is broken up into tectonic plates

crust

the very outer layer of the lithosphere, and commonly referred to as Earth’s surface

divergent plate boundary

a situation where plates move away from each other as a result of rising magma plums

forms mid-oceanic ridges, volcanoes, seafloor spreading, and rift valleys

convergent plate boundary

a situation where plates move toward each other other, leading to subduction

forms mountains, island arcs, earthquakes, and volcanoes

subduction

a situation where one tectonic plate is forced beneath another tectonic plate

transform-fault plate boundary

a situation where plates slide past each other

forms earthquakes, when the tectonic plates are stuck and then quickly slide past each other

convection cycles

a cycle of heating magma that rises up to the surface of the lithosphere, where it cools and expands, spreading out across the lithosphere, before sinking back down into the mantle

oceanic-oceanic convergence

one plate is forced underneath the other, forcing magma up to the lithosphere’s surface, where mid-ocean volcanoes are formed (and later forms island arcs as a result of consistent eruptions)

oceanic-continental convergence

dense oceanic plate is forced beneath a continental plate, and melts back into the magma, forcing the magma up to the lithosphere surface, creating coastal mountains, volcanoes on land, trenches, and tsunamis

continental-continental convergence

once continental place being forced underneath another, forcing surface crust upward, forming mountains

ring of fire

the pattern of volcanoes all around the pacific plate

hotspots

areas of especially hot magma rising up to the lithosphere

soil

a mix of geologic and organic components, including: sand, silt, clay, humus, nutrients, organisms, water, and air

humus

the main organic part of soil, and it is broken down biomass like leaves, dead animals, waste, etc.

soil’s role with plants

anchors roots of plants and provides water and nutrients (nitrogen, phosphorus, potassium, and magnesium) needed for growth

soil’s role with water

filters rainwater and runoff by trapping pollutants in pore spaces and plant roots, allowing for clean water to enter groundwater and aquifiers

soil’s role with nutrient recycling

serves as a habitat for decomposers who break down dead organic matter and return the nutrients to the soil

soil’s role with habitat

provides a habitat for organisms like earthworms, fungi, bacteria, etc.

weathering

the break down of rocks physically, biologically, or chemically

erosion

the transportation of weathered rock fragments by the wind and rain

deposition

the final stage of soil formation, after eroding forces carrying weathered rocks to a different location

soil formation from below

the weathering of parent material, which produces smaller fragments that make up the geological portion of soil

soil formation from above

the breakdown of plants and organic matter adding humus to the soil

parent material

also called bedrock, and determines the soil pH and nutrient content

topography

describes the steepness of soil, where a steep slope can lead to too much erosion but a level ground could increase the rate of deposition

climate

can determine the rate of deposition and breakdown of organic matter

warmer climates lead to faster breakdown of organic matter and more precipitation leads to more weathering, erosion, and deposition

organisms

increase the rate of the breakdown of organic matter

o-horizon

a layer of organic matter (plant roots, dead leaves, animal waste, etc.) on top of the soil

a-horizon

also called the topsoil; largely composed of humus and minerals from parent material

has the most biological activity, breaking down organic matter to release nutrients

b-horizon

also called the subsoil; the lighter layer below topsoil, mostly made of minerals with little to no organic matter and minimal nutrients

c-horizon

the least-weathered soil that is closest to the parent material

soil degredation

the loss of the ability of soil to support plant growth

loss of topsoil

commonly caused by tilling, or turning soil for agricultural, and makes it more easily eroded by wind and rain because it is dried out

compaction

the compression of soil by machines, grazing livestock, and humans; reduces its ability to hold moisture, making it erode more easily and supports less plant growth

nutrient depletion

repeatedly growing crops of the same soil, leading to the removal of nutrients over time and reduces the soil’s ability to grow future crops

soil texture

the percent of sand, silt, and clay

pores

the empty spaces between particles in soil

sand has the biggest pores and clay has the smallest pores

porosity

the amount of pore space a soil has

soil with more sand has a higher porosity and soil with more clay has less porosity

permeability

how easily water drains through a soil; water drains easier through high porosity soil

water-holding capacity

how well water is retained, or held, by a soil; more porous soil has a lower water-holding capacity

ideal soil type

sandy loam; balances the porosity and water-holding capacity

soil acidity

determines the nutrient availability

more acidic soil will indicate less nutrient availability

relative abundance of gasses in the atmosphere

nitrogen (78%), oxygen (21%), argon (0.93%), water vapor (0-4%), carbon dioxide (0.04%)

exosphere

the atmosphere’s outermost layer, where it merges with space

thermosphere

the layer of the Earth’s atmosphere that absorbs harmful X-rays and UV radiation

mesosphere

the middle layer of the atmosphere

stratosphere

second layer of the atmosphere, and it is where the ozone layer is found, which is responsible for absorbing UV-B and UV-C rays

troposphere

the layer of the atmosphere closest to Earth, and it is where the molecules are most dense

although there can be ozone in this layer, if ozone is found in this layer it is harmful to humans as it is a respiratory irritant

temperature gradient

the idea that the layers of the Earth’s atmosphere are based on where temperature ranges change with distance from Earth’s surface

troposphere (cold), stratosphere (warm), mesosphere (cold), thermosphere (hot)

hadley cell

the cycle of air circulation between the latitudes 0 degrees and 30 degrees N and S

steps of the hadley cell

1. more direct sunlight at the equator, warming the air at the equator

2. warm air rises, cools, and expands, allowing water vapor to condense into rain

3. air continues to rise, cool, and expand

4. the cool air expands and spreads out

5. cool, dry air sinks back to Earth at 30 degrees N and S, often forming deserts because of a lack of moisture in the air

6. air moves from 30 degrees N and S to 0 degrees as a result of the former latitude having high pressure, meaning that it will flow back to the low pressure (0 degrees latitude)

coriolis effect

the deflection of objects travelling through the atmosphere due to the spin of the Earth

from 0 to 30 degrees latitude, the wind flows from East to West because of the fact that the Earth spins from West to East

from 30 to 60 degrees latitude, the wind flows from West to East because the high speed of Earth at this latitude keeps it in the same direction as the Earth’s rotation

westerlies

the name for the wind pattern from 30 to 60 degrees latitude, North and South

trade winds

the name for the wind pattern from 0 to 30 degrees latitude, North and South, as a result of the Earth’s rotation

watershed

an area of land that drains all water into a specific a body of water; determined by the slope of the land, as ridges can divide these areas of land

effect of vegetation on watershed drainage

can result in more infiltration and groundwater recharge, if it is greater in scale

effect of slope on watershed drainage

can lead to a faster velocity of runoff and more soil erosion, if greater in scale

effect of soil permeability on watershed drainage

determines the runoff and infiltration rates of watersheds

insolation

the amount of solar radiation reaching an area

solar intensity

dependent on the sunrays’ angle, or how directly the rays strike Earth’s surface, and the amount of atmosphere that the rays must pass through

june solstice

the day during which the northern hemisphere receives the most insolation, as a result of it being maximally tilted towards the Sun

december solstice

the day during which the southern hemisphere receives the most insolation, as a result of it being maximally tilted towards the Sun

march and september equinoxes

the days during which the north and south hemispheres are equally facing the Sun

albedo

the proportion of light that is reflected by a surface, and directly affects surface temperature

higher albedo

the reflection of more light, and the absorption of less light

lower albedo

the reflection of less light, and the absorption of more light

urban heat island

urban areas that are hotter than surrounding rural areas, as a result of low albedos on black roadways and tops

rain-shadow effect

warm, moist air from the ocean, after hitting the “windward” side of the mountain, which then rises and cools above the mountain, and finally the dry air descends down the “leeward” side of the mountain, warming as it sinks

windward side of mountains

typically has lush, green vegetation as a result of facing the warm, moist air that comes from oceans

leeward side of mountains

typically experiences arid desert conditions as air descends past the mountain, typically dry after rising and cooling

gyers

large ocean circulation patterns due to global wind patterns; clockwise in the northern hemisphere and counterclockwise in the southern hemisphere

upwelling zones

areas of ocean where winds blow warm surface water away from a land mass, drawing up colder, deeper water to replace it

benefits of upwelling zones

brings dissolved oxygen and nutrients to the surface, often creating very productive fishing environments

thermohaline circulation

a movement of all ocean currents in order to mix salt, nutrients, and temperature throughout all of them

el niño-southern oscillation (ENSO)

the pattern of shifting atmosphere pressure and ocean currents in the pacific ocean between South American and Australia, or Southeast Asia

leads to the regular shifting from el niño (warmer, rainier) to la niña (cooler, drier), along the South American coast