Download Earth Science Milestones Review Notes Packet

Milestones Review
Minerals
Common Minerals:
Gypsum
Calcite
Fluroite
Diamond
Quartz
gemstones
Must have all 5 characteristics to be a mineral.
Solid- definite shape & volume
Inorganic- nothing in it is living or ever was living
Naturally formed- made by nature, not man-made
Crystalline Structure- has a crystal shape that repeats throughout.
Definite Chemical Composition: made of the same elements in the
same amounts.
Special Properties
Property that only certain
minerals have.
1.Fluorescence- glows
under UV light.
2. Chemical reaction- fizzes
when touched with acid.
3.Magnetism
4.Optical property- makes
double images
5.radioactivity
Properties of Minerals: used to identify the type of mineral it is.
Hardness: how easy/hard it is to scratch it.
Luster: how it reflects light.
Color-the color it appears (least reliable).
Streak- color of the powder of a mineral when rubbed on a porcelain
streak plate.
Density- mass/volume
Crystal shape
Cleavage- splits along smooth, flat surfaces.
Fracture- splits along curved, irregular surfaces.
Moh’s Hardnes Scale
 Minerals with higher numbers will be more resistant, or harder to
scratch.
 Minerals with lower numbers are easy to scratch and can be scratched by any mineral with a
higher number on Moh’s hardness scale.
Rocks
 A naturally made, solid mixture of 1 or more minerals an organic matter (material that was
once living, ie. Fossil).
 Rocks are grouped or classified based on COT:
Composition- what they are made of
Origin- how they are made
Texture- size of mineral pieces/ how they are arranged in a rock.
3 Main types of Rocks
Igneous
Forms from magma or lava
cooling and hardening.
Sedimentary
Forms when sediments are
squished together into new
rock
Metamorphic
Form when extreme heat and
pressure squish a rock, but
does not melt it.
Igneous Rocks
Magma (melted rock under Earth’s surface) or lava (melted rock on Earth’s surface) cools and
hardnes into a solid rock.
2 main types;
1. INtrusive igneous rock
 Forms when magma cools and hardens INside the ground or volcano.
 These have large mineral grains because it is hot like an oven underground, so minerals can
keep growing as magma cools slowly (coarse-grain)
Ex: Granite
2. EXTrusive igneous rock:
* forms when lava cools and hardens on the surface after EXiTing from being underground.
These have small grains because lava cools quickly on surface (Fine Grain).
Examples:
Basalt- fine grain
Pumice- fine grain
Obsidian- no grain; glassy
Obsidian
Granite
Basalt
Sedimentary Rock
 Formed from sediments that have been glued together.
 Type of rock that has fossils in it.
1. Starts with weathering (breaking rocks down into smaller pieces called sediment).
2. Erosion- sediments get carried away by wind or water.
3. Deposition- sediments eventually get dropped off somewhere else and pile up.
4. Compaction- sediments pile on top of each other, compacting (squishing) sediments
together.
5. Cementation- sediments get glued (cemented) together
Examples of Sedimentary Rock:
Conglomeratemade of smooth
round stones glued
together
Breccia- made of
jagged pieces glued
together.
Metamorphic Rock
 Formed when a rock deep underground gets squished or changed by EXTREME HEAT AND
PRESSURE, but does not melt (think flexible like play doh).
 Think of squishing starbursts together with heat and pressure from your hands, but it does not
melt.
2 types of metamorphic rock:
Foliated (folded in layers)
Ex: gneiss
Non-foliated (randomly arranged)
Ex. marble
Rocks Cycle
All rocks can become any other type of rock. Whatever processes they go
through determines the rock they will become.
Weathering- process (action) of rock being broken down into smaller pieces, called
sediment. Different agents cause weathering.
There are 2 types of weathering:
1. Mechanical Weathering: when rock is broken down by a physical force (you can usually
see a crack in the rock or the smaller pieces that have been broken off).
2. Chemical Weathering- when rock is broken down by chemical reactions (minerals get
dissolved, leaving the rock a darker color, can change the mineral composition of the
rock).
Mechanical Weathering by abrasion (rocks are broken into smaller pieces as they
tumble and hit each other).
 Agents of Mechanical weathering: wind, water, ice, gravity, plants, animals,
temperature changes
Wind- wind causes sand to hit larger rock,
slowly breaking it down (like sandpaper).
Reason the Great Sphinx has no nose and
for strange rock formations in desert.
Water- moving water (river) causes small rocks to tumble against each
other, smoothing them and making them rounder and smaller.
Gravity- as rocks tumble down a mountain, bumping into each
other, they break into smaller pieces.
Other agents of mechanical weathering
Ice- water gets into a crack in rock. When it gets cold, it freezes and
expands, pushing the rock further apart. Ice melts, freezes again, and
pushes the rock even further apart. This continues until rock breaks
apart.
Temperature Changes- rock contracts (shrinks when it gets cold)
and expands (gets slightly larger when it gets hot). This
contraction and expansion causes a crack in the rock.
Plants- plant root gets into the crack of a rock. As the root grows,
it widens the crack, pushing the rock apart until it breaks.
Animals- break up rock when burrowing/digging.
Chemical Weathering: rocks break down by chemical reactions, minerals
are dissolved.
 Agents: water, air, weak acids
Water- dissolves minerals in rocks over time.
Air- oxygen in air has a chemical reaction with iron, creating rust.
(rusty bike, rusty mailbox, rusty cans, rusty nails)
Weak acids that cause chemical weathering
Acids in living things- lichens (moss & algae) let out acid (kind of
like spit) that dissolves minerals in rock, changing their color.
Acids in groundwater- dissolve minerals underground,
creating caves and karst topography.
Acid precipitation- acid rain, snow, sleet, or hail
dissolves minerals in rock/statues over time, making
the statue look worn down and sometimes change
color.
Erosion: the process of sediments (sand, dirt, small pieces of rocks being carried away).
Think RO- is in road and rowing (both have to do with movement.
WATER IS THE MAIN CAUSE OF WEATHERING AND EROSION. IT IS THE MOST DESTRUCTIVE OF
ALL AGENTS OF WEATHERING AND EROSION.
Human Activities & Erosion
Human activities cause erosion to happen faster.
Ways to Conserve (save/protect) soil from erosion
Contour Plowingplanting crops
horizontally on a
hill.
Crop rotation- rotate
the type of crop being
planted each season, so
that all nutrients do not
get depleted.
Terracingwhen steps out
cut into a steep
mountainside
and crops are
planted on the
flat part.
Cover crop- planting crops like peanuts and
soybeans that replenish nutrients.
No-till plowingold stalks are laid
on top of soil to
hold soil in place.
Wind breaks- trees are planted around a field to
prevent erosion by wind.
Soil
Soil Composition (made up of):
 Weathered rock & minerals, organic matter (once living things), water, air (WOWA!)
Humus: dark organic matter made from dead, decomposed
plants and animals. Most of this is in the top soil, but some is
moved into Horizon B by the process of leeching.
How soil forms
 Step 1: Solid rock begins to weather (break up).
 Step 2: Small organisms cause chemical weathering, breaking up the rock more.
 Step 3: Small plants can grow. Small plants and some animals die, adding more nutrients
to the soil.
 Step 4: The soil can support larger plants.
Layers of Earth
Crust
-Solid outer shell of Earth.
-Least dense layer (why it floats on top)
2 types: oceanic crust & continental crust.
Oceanic crust: thin, dense, under oceans, made of basalt.
Continental crust- thick, less dense, under continents, made
mainly of
granite.
Mantle -Thickest layer
-Magma is here
-Convection currents in mantle move crust above.
-Divided into 3 layers
Outer -Made of liquid iron & nickel
core
Inner
-Made of solid iron & nickel because it is under SO much
core
pressure, it cannot expand into a liquid. –most dense layer
As you go deeper, it gets hotter and there is more pressure from layers above.
Convection Currents:
 Hotter magma is less dense, so it rises
 Cooler magma is more dense, so it sinks
 This creates a circular motion called convection currents.
Parts of Layers
Lithosphere:
 layer made of crust & solid, upper part of
mantle.
 It is broken into pieces called tectonic
plates.
 Where tectonic plates touch, it is called a
PLATE BOUNDARY.
Asthenosphere
Mesosphere
Pangaea Super continent made of all the continents put together.
 Existed 100s of millions of years ago.
Continental Drift Theory
 Alfred Wegner came up with the idea that the continents were once one large super
continent, and then slowly drifted (moved) apart.
Evidence of continental drift theory:
1.Shape of continent
coastlines fit together
3. the same fossils were found on different
continents. The animal/plant couldn’t swim
across the ocean.
2.mountains/rocks match up on different
continents
* mountain ranges & layers of rock were
identical on different continents.
4. coal-forms in warm, tropical places, but is
found in cold places today.
Glacial scratchesformed by glaciers
in cold places, but
found in hot,
tropical rainforests.
Fossils
fossils are found only in sedimentary rock.
The fossils in the bottom layer are the oldest fossils. The newer
fossils are at the top. Each layer of rock is called a strata.
4 Types of Fossils
Bodythe actual bone or tooth of an animal.
Cast- a copy of the shape of the original
organism. minerals or other materials fill in
the mold and
harden into the
original shape of the
organism.
MoldImpression left in the rock by the organism.
Trace- footprints,
scratches in rock
(something the organism
did when it was alive)
(Mold of a trilobite).
Tectonic Plates
 Lithosphere is broken into pieces called tectonic plates. Convection currents in the
mantle move the tectonic plates above. Where the plates meet are called boundaries.
There are 3 types : convergent, divergent, & transform.
Convergent Boundary- where 2 plates come together/collide.
Oceanic-oceanic Convergent
Oceanic slides under another
oceanic plate.
Continental-oceanic
convergent
Oceanic plates slides under
continental plate.
Continental-continental
convergent
Plates collide and both
push up.
Creates volcanic islands.
Trench- crack where one plate
goes under the other.
Creates volcanic mountains.
Creates mountain ranges
Trench- crack where one plate
goes under the other.
Divergent Boundary
 Where to plates move apart (divide)
 Causes rifts (cracks in Earth), where magma comes up
 Magma piles up, cools, and hardens, creating MIDOCEAN RIDGE
 As more magma comes up, it pushes older ocean floor
away, causing sea-floor spreading.
 Ocean floor is created here
Transform Boundary
2 plates slide past each other, creating a fault and causing
earthquakes.
Features of ocean floor & mid-ocean ridge.
F
H
A.
B.
C.
D.
Continental slope
Seamounts
Abyssal plain
Mid-ocean ridge/rift
E. volcanic island
F. continental shelf
G. trench
H. continental rise
Hydrology:
Distribution of water 97% of all water is saltwater. 3% is freshwater (2% is locked in polar ice caps & 1% is
freshwater available to us in lakes, river, streams, groundwater).
o Humans have access to less than 1% of freshwater.
Water cycle: The sun drives the water cycle.
Evaporation- water changes from a
liquid into a gas, and rises into the
sky.
Condensation- process that forms
clouds, water vapor becomes cool
and changes from gas to a liquid,
making clouds.
Transpiration- water leaves the
leaves on trees and plants and rises
into the sky as water vapor.
Runoff- water that runs on surface
of the Earth.
Precipitation: rain, snow, sleet, hail that comes out of the clouds when the clouds become too
heavy.
Infiltration- process of water traveling through the ground to become groundwater.
Collection- when water gathers together to form a body of water (puddle, lake, ocean)
Groundwater- water that collects underground.
Label the oceans
Southern Ocean
Order of oceans (largest to smallest)- Pacific, Atlantic, Indian
Ocean Composition
 Salinity of ocean water is 3.5% or 35g/1000mL (3.5% of ocean water is salt). Sodium
chloride is the main solid dissolved in ocean.
 Carbon dioxide and oxygen are dissolved gases in ocean
Waves- a disturbance that transfers energy through matter or space.
 As a wave moves through the ocean, it is the energy that moves, not the actual water
particle. The waves causes individual water particles to move in a circle, NOT across the
ocean.
Cause of Waves:
 Main cause: wind
 Other causes: underwater earthquakes and underwater landslides
Parts of a wave:
 Crest: highest point of a wave
 Trough: lowest point of a wave.
 Wavelength: distance from one crest to the next
crest, or one trough to the next trough.
 Wave height: distance from crest to trough.
Currents
 Like a fast-moving river in the ocean.
 Surface currents: Caused mainly by prevailing winds (winds
that blow all the time).
 Deep-ocean currents: caused by differences in density
(saltier and colder water is more dense).
 How water, animals, and objects move around the ocean.
 Warm water currents- usually on surface, because warmer
water is less dense. This warm water comes from the equator.
 Cold water currents- usually deep currents, because colder
water is more dense. This cold water comes from the North
and South poles.
 The continents cause the currents to deflect, or move in
circular motion together, called gyres.
 warm currents come from equator; cool currents come from poles.
Coriolis Effect
 as the Earth spins, it causes currents and winds to move in
a curved path instead of a straight line. This is called
Coriolis Effect.
Surface Currents Effect Climate
ex: Gulf Stream is a warm surface current that
comes from the Gulf of Mexico. It carries warm
water to Western Europe, making the air and
climate warmer than it usually would be. At that
distance from the equator, it is usually colder,
but Gulf Stream makes it warmer.
Cold water currents make air above them cool,
thus making the climate of nearby places cooler than they would be.
Tides: rise and fall of the ocean on the shore,
caused by the gravitational pull of the moon
 Low tide: the lowest point the ocean comes
on shore in a day.
 High tide: the highest point the ocean comes
on shore in a day.
 Tides changes every 6 hours.
 If there is a low tide at 9am, 6 hours later, at
3pm it will be high tide. At 9pm, it will be low
tide again, and 3 am, it will be high tide.
 12 hours between low tide and the next low tide
 12 hours between high tide and the next high tide
High Tide
Low Tide
Spring Tide
 The greatest difference between a high tide and a low tide.
 When the Sun, Earth, and Moon are in a straight line, we a full moon or a new moon.
 During these moon phases, we have a spring tide.
 When it is SPRING tide, sun, earth, & moon are in a STRAIGHT line.
Neap Tide
 The least difference between a low tide and a high
tide.
 Happen when sun, moon, earth are at right angles
to each other (you can draw an N to connect themN for Neap).
 We experience a first quarter or 3rd quarter moon
during a neap tide.
What Spring Tides & Neap Tides look like on shore:
METEOROLOGY
Weather: atmospheric conditions of a location at a certain time.
Climate: the average conditions of a location over a long time (is it usually rainy, usually hot,
usually cold, etc).
Atmosphere: mixture of gases that distributes heat and allows life on Earth to exist.

Made of 78% Nitrogen, 21% Oxygen, & 1% of
water vapor, carbon dioxide, & other gases.

Air pressure is greatest at the surface; as you go
higher up in the atmosphere, there is less air above you, so the air pressure is lower.

Has 4 main layers.
o
Troposphere: bottom layer of atmosphere’
where most gases in atmosphere are found; plants, animals, humans are all here;
most clouds and weather are here; hot air balloons and air planes.
o
Stratosphere: contains ozone layer (traps
harmful UV rays), where weather balloons are.
o
Mesosphere: middle layer, coldest layer, where
meteors burn up (shooting stars)
o
Thermosphere: outer layer; International Space
Station, spaceships, satellites, and auroras are here.
Land & Water heat up unevenly

Land heats up faster and cools down faster.

Water heats up slower and cools down slower.

Liquids and gases become heated by convection
currents (cooler water/air sinking, warmer water/air rising)
Air always moves from high pressure (air
sinking) to low pressure (air rising). This is what
creates breezes and winds.
Local Winds: mountain breeze, valley breeze, sea
breeze, land breeze. They are named after where they come from.
Sea Breeze:
 Happens in morning
 Water takes longer to warm up than land.
Land heats up first and warm air rises (low
pressure).
 Air is sinking over water because it is
cooler (high pressure).
 Air wants to move from high pressure to
low pressure, so breeze comes from the
sea to the land.
Land Breeze:
 Happens at night
 Land cools fastest, but water is still warm.
Warm air rises over ocean and cool air sinks
on land (high Pressure). Air wants to move
from high pressure (land) to low pressure
(water).
 Breeze comes from land towards the sea.
Air Masses
 Large masses of air that have the same moisture and temperature throughout.
 Amount of moisture and temperature depends on where they form.
 Look at the diagram below:
Fronts
 Place where 2 air masses collide
Cool air mass is over
a city; warm air mass
wants to move in and
take over.
Warm Front
Causes light, drizzly
weather.
After, weather is
warm and clear.
Cold
Front
Warm air mass is over
a city, and cold air
mass wants to move
in.
(cold air mass is like a
villain, so it causes
severe weather)
Thunderstorms, snow,
rain
After, weather is cool and clear
Occlouded Front
When a cold air mass
is already there,
another cold air mass
wants to move in, and
a warm air mass gets
stuck in the middle.
Causes heavy rain,
heavy snow
Stationary
2 air masses get stuck and neither has enough
energy to
push the
warm air
mass up, so
we have days
of cloudy,
drizzly
weather.
Cumulonimbus clouds- cumulus clouds that that grow into thunderstorm clouds. Also known
as thunderheads.
Thunderstorms:
 Differences in air pressure can also produce powerful local winds and storms.
 The low density, warm air will form clouds when it reaches colder air in the sky.
 As low density moister rises high in the sky, it may freeze into particles that are
electrically charged.
 These charged particles can produce lightning and thunder.
 Moist, low pressure air near the ground produce thunderstorms.
 Thunderstorms form within large cumulonimbus clouds, also known as thunderheads.
Tornadoes:
 Tornadoes are swiftly turning, very low-pressure funnels or air. They produce the
fastest moving winds on Earth.
 Tornadoes develop in low, heavy cumulonimbus clouds.
 Most likely to occur in spring and summer, often in the late afternoon when the ground
is warm.
 Tornadoes occur more often in the U.S. than in any other country.
Hurricanes
 Tropical storms are born over warm water near the equator.
 Very large and powerful tropical storms with spinning winds are called tropical cyclones.
 In the Atlantic Ocean and the eastern Pacific Ocean, tropical cyclones are called
hurricanes.
 In the northwest Pacific Ocean, they are called typhoons.
 Energy from the sun warms ocean water.
 Energy absorbed by the ocean water causes the water on the surface to evaporate.
 The warm, evaporated water rises.
 This produces an area of low pressure called a tropical depression.
 This is when clouds begin to form.
 The air in the center of a depression in the Northern Hemisphere begins to spin
counterclockwise.
 In the Atlantic Ocean, global winds push the storm westward.
 As the storm continues to move over warm water, heat from the water feeds it.
 As its air pressure drops lower its winds move faster and faster.
 A hurricane has a typical shape.
 The eye of a hurricane is a place of very low pressure with no clouds above it.
 In the eye, it is very calm and sunny.
 The most violent winds in a hurricane form the wall of the hurricane’s eye.
 Eventually, a hurricane will travel over cooler water or land.
 Once this happens, the hurricane can no longer feed on heat energy from warm water.
Astronomy:
Rotation






Earth spinning on its axis
1 complete rotation in 24 hours
Causes day & night
Earth is tilted on its axis at 23.5*
Rotates west to East (WhEe!)
Objects appear to move East to west
(opposite direction that Earth is
rotating).
Revolution:
 Earth going in its orbit around the sun.
 1 complete revolution= 365 days (1
year)
 Causes YEARS & SEASONS
 Orbit: path of an object around another
object.
 Orbit shape- ellipse (egg shaped).
Reason the sun
appears to rise,
move across the
sky, & set.
Reason we see different constellations
throughout the year.
Seasons: Caused by Earth’s TILT & REVOLUTION around the sun.
When the Northern Hemisphere is tilted towards the sun= summer
Tilted away from sun= winter
Neither tilted towards nor away from sun= spring or fall
Seasons in Northern Hemisphere & Southern Hemisphere are always opposites.
2 solstices
 Summer solstice- 1st day of summer (June 21 or 22), most hours of daylight, sun heats
surface longer so it is hotter, N.H. gets more direct sunlight.
 Winter solstice- 1st day of winter (Dec. 21 or 22), least hours of daylight, sun heats
surface for less time so it is cooler. N.H. get less direct sunlight.
2 equinox:
 Spring (vernal) equinox: 1st day of spring (March 21 or 22), equal hours of daylight &
night time, equator gets direct sunlight.
 Fall (autumnal equinox: 1st day of fall (September 22 or 23), equal hours of daylight &
night time, equator gets direct sunlight.
Astronomy
Formation of universe & solar system
1. Big Bang- theory that everything that exists started out concentrated in one dot,
which exploded (the Big BANG) and the universe existed.
2. Helium & hydrogen are left over and form stars.
3. Gravity pulls stars together to form galaxies
4. In 1 of those galaxies, a nebula (space dust & gas) is hit, and begins to spin. Matter is
pulled together at the center, forming the sun, and then our planet.
(Universe created first, then stars, galaxies, solar system (sun, then planets)).
Our Location
 In the Milky Way Galaxy, on one of the outer arms, but
not on the very tip of the arm.
 Our star (the sun) is one of 3 billion stars in our galaxy.
 Milky Way galaxy is a spiral shape.
Measuring Distance in Solar System (used to measure
distances outside of Earth)
Astronomical Unit: distance between sun
Lightyear: distance light travels in a year.
and Earth.
1 a.u.= 150,000,000 km
In 1 year, light can travel 9.5 trillion billion
km.
What causes planets to stay in orbit around the sun?- inertia & gravity
 Inertia- tendency of an object to keep moving in the same direction.
 Gravity- pulls objects towards the sun.
Why constellations appear to move across the sky?
because the Earth sees different constellations as it moves in its orbit around the sun.
Why sun appears to move across sky during the day?
 Because of Earth’s rotation
Models/Theories about our Solar System
Heliocentric Theory
 Theory that the sun is in the center of
the universe
Geocentric Theory
 Theory that the Earth is in the center
of the universe
Comets, Meteors, Asteroids
 Comet “dirty snowball”- made of ice, rock, & dust.
When it gets closer to the sun, ice turns into
atmosphere of gas around the rock, forming a coma.
 Coma gets blown away by suns energy, creating a tail.
 Orbit sun or plunge into sun
Meteors
Meteoroid
Chunk of rock & metal in
outer space.
Meteor
Chunk of rock & metal that
enters Earth’s atmosphere &
burns up in mesosphere.
Meteorite
Chunk of rock & metal that
reaches Earth’s surfaces.
Asteroids
 Chunks of rock & metal in space.
 Usually found in ASTEROID BELT,
between Mars & Jupiter.
Inner vs. Outer Planes
Inner Planets
smaller
Aka terrestrial
Planets Closest to sun
Rocky surfaces
Mainly rock with gaseous atmosphere (more dense)
No rings
Few moons
Outer Planets
larger
Aka gas giants
Planets furthest from sun
No surface
Mainly gases (less dense)
Most have rings
A lot of moons