Earth Science

Plate tectonics

theory that explains the:

- movement of the continents

- changes in Earth's crust caused by internal forces

Plates

rigid blocks of crust and upper mantle

- move along the hot upper mantle

- make up the lithosphere

Divergence

- 2 plates move away from each other

- hot mantle rock rises

- creates new sea floor

- creates new oceanic crust (2-10 cm per yr)

-Mid-Atlantic

Convergence

- crust collides with another oceanic plate or continental plate

- oceanic crust sinks

- forms a trench

- forms volcano activity

- continent to continent plate collisions

Subduction

- oceanic plate, dense, slides under continental plate

- oceanic plate plunges into the mantle

- forms a trench

Trench

- forms b/c of subduction

- may cause a volcano

Transform Fault

- 2 plates slide past one another

- parallel

Rifting

- sea floor spreads

- occurs at mid-ocean ridges

- Red Sea

- new material is added to inner edges of separating plates

- plates grow larger, ocean basin widens

- how Pangaea was broken

- created Atlantic Ocean

Atmosphere - Dry air components (3)

- dry gas

- water vapor

- solid particles (dust from soil, etc.)

Atmosphere dry gases (4)

(N2) Nitrogen - 78.09%

(O2) Oxygen - 20.95%

(Ar) Argon - 0.93%

(CO2) Carbon Dioxide - 0.03%

Atmosphere (4 layers) - temperature based

Troposphere (earth)

Stratosphere

Mesosphere

Thermosphere (space)

Troposphere

- closest to Earth's surface

- weather here

- most water vapor/dust

- increasing altitude = air temp down

- 7 miles long

Stratosphere

- little water here

- clouds are rare

- OZONE LAYER

- air temp = constant, increases with height (absorbs solar energy & ultraviolet rays from ozone layer)

Mesosphere

- air temp decreases with height

- coldest layer

Thermosphere

- extends to space

- O2 molecules absorb energy from the Sun

- temp. increases with height

- lower part = ionosphere

- upper part = exosphere

Ionosphere

- lower part of thermosphere (space)

- charged particles (ions) & electrons here

- gases excited by solar radiation, gases give off light; glow in the sky

- aurora borealis

Exosphere

- upper part of thermosphere

- gas molecules are far apart here

- Van Allen belts

- held together by Earth's magnetic field

Orogeny

natural mountain building

Mountains

- by volcanic action

- tectonic plate collisions

- igneous, metamorphic, sedimentary rocks

Himalayas

- highest mountains in world

- Mt. Everest

- India collided with Asia

- folded mountain (folding of rock layers)

Fault-block mountains

- Utah, AZ, NM

- plate mvmnt = tension forces

- normal faults, hanging wall slides down

Dome mountains

- magma tries to push up through the crust

- doesn't break the surface

- blister on Earth's surface

Upwarped mountains

- Black Hills of South Dakota

- arching of the crust

- formed by rock thrust upward along high angle faults

Mountain formation

- folding

- faulting

Folded Mountains

- Alps, Himalayas, Appalachian Mts.

Faults

- fractures in crust b/c of tension/compression forces

Dip-slip fault

- mvmnt of plates is vertical & opposite

- normal faults when hanging wall moves down

Reverse faults

- rock above fault plane moves up

- thrust faults

Strike-Slip faults

- horizontal movement along the fault

- transform fault (along plate boundaries)

- San Andreas fault in CA --> tranform fault

Oblique- slip faults

- vertical & horizontal movement

Dormant volcano

- btwn eruptions

- still signs of internal activity - could erupt

Ring of Fire

- faults & volcanoes

- belt of active faults/volcanoes in Pacific Ocean

Volcanic Mts

Mt. Etna, Italy

Mt. Kilimanjaro, Africa

3 Types of Volcanic Mts.

- shield volcanoes

- cinder-cone volcanoes

- composite volcanoes

Shield Volcanoes

- quiet erruptions

- lava from crater

- flows onto Earth, cools into igneous rock

- lava flow --> large volcanic mountain

- Mauna Loa in Hawaii = shield volcano

Cinder-cone volcanoes

- explosive eruptions

- lava droplets - cool and harden into cinders and ash

- form steep cone hill

- small, form rapidly

Composite volcanoes

- bulit by lava flows & ash/cinder

Mt. Fuji in Japan

Mt. St. Helens in WA

Mt. Vesuvius in Italy

Lava cools

igneous rock

Intrusive rock

-igneous rock

-formed below Earth's surface

-batholiths

-Sierra Nevada Mts.

Extrusive rock

-igeneous rock

-formed at Earth's surface

Dikes

- old lava tubes formed when magma entered vertical fracture & hardened

Sill

- magma btwn rock layers

- thin sheet

Laccolith

-thicker than a sill

-doesn't flow easily

-pools & makes a surface dome

Caldera

- formed by the collapse of the top of a volcano

- empties magma chamber

- forms a caldera/crater

3 Types of Rocks

- sedimentary

- igneous

- metamorphic

Sedimentary rocks

- lithification

- fluid sediments --> solid rocks

- compaction, compress sediments

- cementation -->sediments -->sedimentary rock

- fossils wahhaha

Metamorphic rocks

- high temps & pressure

- metamorphism

- new & diff minerals b/c of chemical reactions with heated water/dissolved minerals

- foliated (leaflike) & unfoliated

- foliated = compressed parallel bands of minerals (striped)

- slate, schist, gneiss = foliated/striped

- quartzite, marble (unfoliated/not banded)

Igneous Rocks

- made from molten rock

- molten rock = magma

- when magma cools --> form crystals

- more slowly cools = larger crystals

- obsidian = glassy texture, cools b4 crystals can form

Minerals

-natural, nonliving

- definite chemical composition

-crystalline structure

- ores (mined)

- rocks (made of 1+ minerals)

Cirques

-remains of glacial sources

- frost wedges the rock at bottom of glacier

Ice Age

- glaciers advanced over large portion of the continent

- 2-3 million years ago

- plate tectonics

- changes in Earth/Sun's axis

Fossilization

-

Deposition

- sedimentation

- material deposited from 1 area to another

Types of weathering (2)

- physical weathering

- rocks are broken down into smaller rocks, no chem change - exfoliation

- chemical weathering (water, O2, CO2 make it happen)

- weak acid breaks down rocks

Uniformitarianism

- laws that operated in geologic past operate still today

- forces long time ago are still working

Catastrophism

- Earth was shaped by catastrophic events

Absolute Dating

- use of radioactivity 2 make guesses @ Earth's age

- amt of radioactive material in rock vs. amt decayed in another element

Carbon dating

- used to calculate the age of a fossil

Planets

-8

-Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

Parts of the Sun

- core (fusion, hydrogen gas -->helium gas), solar energy

- photosphere (surface of sun, sunspots)

- chromosphere (red portion, solar flares)

- corona (transparent area of sun, see in total eclipse)

Stars

- ball of hot, glowing gas

- hot/dense enough to trigger nuclear reactions

- nuclear rxns = how the star is fueled

- most stars have > masses than sun, but sun is closer

- need mass to trigger nuclear rxns 2 create energy

- less mass = planets or brown dwarfs

Brightness of a Star

- measure it's magnitude

- luminosity

Magnitude

- how astronomers rank brightness of stars

- according to how bright they appear 2 humans

- lower magnitude = brighter star

- magnitude stars = 20 of brightest stars that can be seen from Earth

- first stars noticed at night

Luminosity

- total amt of energy radiated by the star per second

- watts

Galaxies

- vast collections of stars

- irregular, elliptical, spiral

- Earth's galaxy = Milky Way, spiral galaxy

Pulsar

- a variable radio source

- emits signals in short, regular bursts

- it's a rotating neutron star

Quasar

- an object that photographs like a star

- has an extremely large redshift

- variable energy output

- it's the active core of a distant galaxy

Black holes

- objects that have collapsed

- light can't escape from the surface

- light is trapped by gravitational field

Nebula

- cloud of gas & dust

- gravity can make dust produce stars

- particles attract 2 each other

- star grows, temp. increases

- star glows, fusion in core, releases energy

Red giant / Super giant

-dying star

- hydrogen is exhausted, core collapses, temp rises

- released heat produces helium

White dwarf

- the dying core of a giant star

Nova

- star, sudden increase in brightness

- fades back to original brightness

Supernova

- radiates great light energy

Black hole

- star with condensed matter and gravity so intense that light cannot escape

Asteroids

- found btwn Mars & Jupiter

Comets

- masses of frozen gases, cosmic dust, small rocky particles

- most commets come from dense cloud behind Pluto

- nucleus, coma, and a tail

Halley's comet

Meteoroids

- rock & metal particles

- meteor = burning meteoroid (burns when goes through Earth's atmosphere) -- "shooting star"

Meteorites

- meteors that strike the Earth's surface

- Barringer Crater

Kuiper Belt

- small bodies orbiting the Sun beyond Neptune

- remains of early phases of solar system

- short-period comets

Theories - Origin of Solar System

- tidal hypothesis (collision of sun & large star, hot gas condensed into 9 planets)

- condensation hypothesis (rotating clouds of dust & gas, condensation formed sun, smaller clouds = planets) --> accepted hypothesis

Theories - Origins of Universe

- big bang theory (explosion of mass/matter/energy - galaxies formed from this material as it cooled)

- steady state theory (universe is continuously renewed, galaxies are created/replaced)

Oscillating Universe Hypothesis

- universe will oscillate (expand/contract), galaxies move away from one another, slow down & stop

-when move towards each other = activate explosion (another big bang)

Solstices

- 2 days of year

- Sun is farthest from Earth's equitorial plane

- summer solstice (June) - northern hemisphere leans towards Sun - have winter

- winter solstice (Dec.) - southern hemisphere leans towards sun - has summer

Spring tides

- strong tides

- when Earth, Sun, moon are in line

- Sun and moon exert gravitational force on Earth --p> increase tidal bulge

- during full moon and new moon

Neap tides

- weak tides

- when gravitational forces of moon/Sun are perpendicular

- during quarter moons

Phases of the moon

- moon rotates around the earth every 27 days

New moon

- moon is invisible/ 1st signs of a crescent

- when sun and moon are on same side of earth

Full moon

- when moon and sun are on opposite sides of Earth