Unit 4 - Earth Systems and Resources

core

inner most of Earth’s interior comprised mostly of iron and nickel with a solid inner layer and liquid outer layer

mantle

above the core and contains 3 parts: a layer of magma, asthenosphere, and lithosphere

magma

molten rock

asthenosphere

outer part of mantle composed of semi-molten rock

lithosphere

outermost layer and includes solid upper mantle and crust, made up of tectonic plates

crust

provides most elements that make up life

plate tectonics

lithosphere divided into plates that are in constant motion

earthquake

sudden movement of Earth’s crust caused by release of potential energy from movement of tectonic plates

• epicenter is surface of Earth right above place where rock ruptures

volcanos

a vent in the surface of the Earth that emits ash, gas, or molten lava, only occur over a hotspot

Hotspots

place where molten material from mantle reach lithosphere

Tsunami

series of waves in ocean caused by seismic activity or undersea volcano that causes massive displacement of water

oceanic plates

lie beneath the ocean, dense, and rich in iron

continental plates

lie beneath land masses, lighter and rise above oceanic plates

divergent boundary

tectonic plates move away from each other

• result in seafloor spreading, earthquakes, volcanos, and rift valleys

seafloor spreading

rising magma forms new oceanic crust on seafloor

convergent boundary

plates moves toward one another and collide

• cause subduction

• result in earthquakes, volcanos, mountains, island arcs

subduction

plate with more density moves beneath less dense plate which results in volcanos and island arcs

island arcs

chain of islands formed by volcanos

collision zone

earths crust pushed up to to form mountain range → plates of same density

transform boundary

tectonic plates move sideways past each other and rub against each other

• result in earthquakes

fault

fracture in rock caused by movement of earth’s crust —> fault zones such as San Andreas Fault in California

Ring of Fire

a massive, horseshoe-shaped tectonic zone surrounding the Pacific Ocean → intense earthquake and volcano activity

igneous rocks

rocks formed directly from magma

• balsaltic rock and granitic rock

balsaltic rock

dark rock with high concentrations of iron, magnesium, and calcium → dominant in oceanic plates

granatic rock

lighter colored rock made up of feldspor, mica, and quartz (form sand) → dominant of continental plates

sedimentary rocks

forms when sediments such as mud, sand, or gravel is compressed → long periods of time and holds fossils

metamorphic rocks

when igneous, sedimentary, or other metamorphic rocks are subjected to high temperatures and pressure → building materials like marble

rock cycle

constant formation, alteration, and destruction of rock → slowest of earth’s cycles

weathering

rock is exposed to air, water, chemical compounds, or biological agents

physical weathering

mechanical breakdown of rocks and minerals by water, wind, temperature variations, plants, and animals

chemical weathering

breakdown by chemical reactions or dissolving of chemical elements from rock which releases essential nutrients and occurs on newly exposed rock

acid rain

rain high in sulfuric acid and nitric acid —> forms from sulfer dixode in air as a result of human induced weathering

erosion

physical removal of rock fragments from landscape or ecosystem through either wind, water, and ice or living organisms

parent material

underlying rock material from which inorganic compounds of soil derived

• quartz sand = nutrient poor (Atlantic coast of U.S)

• calcium carbonate sand = high agricultural productivity (Lake Champlain)

horizons

horizontal layer in soil defined by physical features like color and texture → depend on climate, vegetation, and parent material

O-horizon

surface layer composed of detrities in various stages of composition → humus

humus

most fully decomposed organic matter in lowest section of O-horizon

A-horizon (top soil)

top layer of soil where organic material and minerals have been mixed

E-horizon

zone of leaching found in some acidic soils

B-horizon (subsoil)

composed primarily of mineral material and very little organic matter

C-horizon

least weathered and similar to parent material

porosity

size of air spaces between particles

permeabiity

ability of water to move through

cations

positively charged mineral ions

cation exchange capacity (CEC)

ability of soil to store and release cations → high CEC = clay soil = more desireable for agriculture

soil acids

aluminum and hydrogen

base saturation

proportion of soil bases to soil acids, percentage

high CEC + high base saturation

high productivity

watershed

all the land in the area that drains into a particular water body

insolation

incoming solar radiation, main source of energy

albedo

percent of sunlight reflected from surface → high albedo = reflect more, absorb less, earth average of 30%

March (20 or 21) Equinox and September (22 or 23) Equinox

suns rays strike equator directly → 12 hours of darkness and 12 hours of sunlight

June (20 or 21) Solstice

Sun is directly above tropic of cancer and northern hemisphere experiences most amount of sunlight

December (21 or 22) Solstice

sun directly above tropic of capricorn and Northern Hemisphere experiences shortest day of the year

Troposhere

a layer of the atmosphere closest to the surface extending

• 10 mi above surface of Earth

• densest layer of atmosphere

• earth’s weather occurs

• height extending due to global warming

stratosphere

above troposphere

• 10-31 mi above surface of Earth

• contains ozone

• absorb UV and convert infrared radiation which is released as heat

• upper stratosphere is warmer

Ozone

a pale blue gas composed of molecules made up of oxygen atoms (O3)

mesosphere

above stratosphere

• 31-53 miles above surface of the Earth

• where most meteors burn up

thermosphere

above mesosphere

• 53-375 miles above surface of the Earth

• protects harmful radiation

• northen lights

exosphere

outer most layer

• 375 - 6200 miles above surface of Earth

• satelites orbit planet

saturation point

maximum amount of water vapor in air at given temperature

• temperature falls = saturation point decreases = leads to precipitation

pressure

air rises higher = decrease = air expands

air lower = increase = air contracts

adiabatic cooling

colling effect of reduced pressure

adiabatic heating

heating effect of increased pressure as it sinks to earth

latent heat release

release of energy when water vapor condenses into liquid water

atmospheric convection currents

global patterns of air movement initiated by unequal heating of Earth

Hadley Cells

convection current between the equator and 30 north and south

• 30 north and south typically hot, dry deserts

intertropical convergence zone

latitude which receives most sunlight which causes ascending branches of the two Hadley cells to converge

• dense clouds and thunderstorm activity

Polar cells

convection current formed by air that rises at 60 north and south and sinks at poles (90 north and south)

• 60 north and south = rising air cools and chugs into precipitation

Ferrell Cells

convection current that lies between Hadley and polar cells

gyres

large scale pattern of water circulation

• clockwise = northen hemisphere

• counterclockwise = southern hemisphere

upwelling

upward movement of ocean water toward the surface as a result of diverging currents

thermohaline circulation

oceanic circulation pattern that drives mixing of surface and deep water

Rain shadow

region with dry conditions found on leeward side of mountains → sierra nevada, great basin, mojave desert

El Nino

reversal of win/water currents in Southern Pacific

• warm air/water moves east instead of west toward South America

• suppreses upwelling

• cooler, wetter conditions in SE U.S and dry weather in U.S, Canda, Southern Africa, and SE Asia

• poor crop yields

La Nina

following El Nino trade winds reverse strongly causing hot/dry regions to become cooler/wetter