Unit 1 – EARTH MATERIALS SCIENTIFIC METHOD – 6 Step

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Unit 1 – EARTH MATERIALS
SCIENTIFIC METHOD – 6 Step process that scientists use to investigate problems or questions –
 Includes: 1 – Problem Statement/Ask a Question 2. Gather information/research 3. Form a Hypothesis 4. Test
the Hypothesis 5. Record data and analyze results 6. Draw conclusions/Communicate Findings
 Variables – things/factors that can change in an experiment
o Constant/control – the factor that stays the same
o Dependent – the factor that is being measured
o Independent – the factor that is being tested/changed
*
Problem statement – should determine a cause/effect relationship – include an investigation that is testable
_ independent and dependent variable (respectively)
 Hypothesis – an educated guess usually formulated in an “If______, then_______ statement.
MEASUREMENT & SAFETY –
SI Units – System of International Units – used by ALL scientists around the world – the metric system
MATTER – anything that has mass and takes up space
 atoms: smallest particle of matter
 elements: made up of one or more atoms – substance that cannot be broken down into simpler substances
 compounds : made up of two or more elements – substance is joined by chemical bonds
MINERALS - 4 main characteristics – naturally occurring, crystalline structure, inorganic (nonliving), & solid made of one
or more elements
 Silicate – contain a combination of silicon and oxygen
 Nonsilicate – does not contain a combination of silicon and oxygen
MINERAL TESTS
 Color – not very reliable
 Luster – the way light reflects on the mineral’s surface
 Streak – true color of mineral – rub the mineral across a porcelain plate
 Cleavage – how a mineral breaks – along smooth , flat surfaces
 Fracture – how a mineral breaks – uneven, curved, irregular surfaces
 Hardness – a mineral’s resistance to scratching – Moh’s Hardness scale – Diamond hardest known
substance
 Density – how much matter is in an object/substance given amount of space
ROCKS - naturally occurring, mixture of one or more minerals, organic (living), and solid
 Igneous – formed by cooling and hardening of magma
o Intrusive – formed inside/below the surface- large/coarse grains – lots of time to form - granite
o Extrusive – formed outside/above the surface – small/fine grains – very little time to form - basalt
 Sedimentary – rock that is formed by weathering, erosion, compaction, and cementation – has strata (layers)
o Clastic – formed by depositing of sediment in layers - sandstone
o Chemical – formed from solutions of dissolved minerals and water - halite
o Organic – formed from the remains of animals or plants – limestone/coal
 Metamorphic – rock that is formed over time, under heat and pressure
o Foliated – mineral grains arranged in planes or bands – gneiss
o Nonfoliated – mineral grains are not arranged in a pattern – marble
ROCK CYCLE – the continuous process by which new rock forms from old rock material – a cycle
NATURAL RESOURCES- any natural material that is used by humans, such as water, petroleum, minerals, forests, and
animals
 Renewable resources - a natural resource that can be replaced at the same rate at which the resource is
consumed
 Nonrenewable resources - a resource that forms at a rate that is much slower than the rate at which it is
consumed
FOSSIL FUELS - a nonrenewable energy resource formed from the remains of organisms that lived long ago
 petroleum (oil) - extracted by drilling - formed from microscopic sea organisms - liquid form
 natural gas - formed from microscopic sea organisms - causes less pollution - gaseous form
 coal - sedimentary rock that forms from partially decomposed plant material
ALTERNATIVE ENERGY RESOURCES
 Nuclear Energy - energy released by a fission or fusion reaction
 Chemical Energy - energy released when a chemical compound reacts to produce new compounds -hydrogen
cell
 Solar Energy - energy received by the Earth from the sun in the form of radiation
 Wind Power - the use of a windmill to drive an electric generator
 Hydroelectric - electrical energy produced by falling water, damming up a river
 Biomass - organic matter that can be a source of energy - wood, gasohol
 Geothermal - energy produced by heat within the Earth - around volcanoes, geysers
FOSSILS/GEOLOGICAL TIME
 Uniformitarianism – principle that states that geologic processes that occurred in the past can be explained by
current geologic processes
 Catastrophism – principle that states that geologic change occurs suddenly
 Superposition – principle that states that younger rocks lie above older rocks if the layers have not been
disturbed
 Geologic column – an arrangement of rock layers in which the oldest rocks are at the bottom - developed by
piecing together different rock sequences from all over the world
 Unconformity – a break in the geologic record created when rock layers are eroded or when sediment is not
deposited for a long time
 Fossil – remains or physical evidence of an organism preserved by geological processes
 Trace fossils – a fossilized mark that is formed in soft sediment by the movement of an animal (tracks)
 Index fossils – fossil that is found in the rock layers of only one geologic age and that is used to establish the age
of the rock layers
FOSSILS ARE OFTEN USED TO INTERPRET THE PAST – CLIMATE CHANGES AND ENVIRONMENTAL CHANGES
***GEOLOGIC TIME – standard method used to divide the Earth’s long natural history into manageable parts
***GEOLOGIC EVENT – a catastrophic event that changed Earth’s climate and/or environment ex. (65 million years ago,
the dinosaurs died out – cause possible asteroid impact
WEATHERING AND EROSION
WEATHERING - process by which rock materials were broken down by the action of physical or chemical processes
 Physical weathering – breaking down of rock by physical means
o Ice wedging
o Wind
o Water
o Gravity
o Plants
o Animals
 Chemical weathering – process by which rocks break down as a result of chemical reactions
o Water
o Weak acids
o Air - oxidation
o Lichen (fungi)
CLIMATE AFFECTS WEATHERING – MORE MOISTURE, WIND, ELEVATION, AND MORE OR LESSTEMPERATURE = MORE
WEATHERING
***SOIL – loose mixture of small mineral fragments, organic material, water, and air that supports growth of vegetation
o Bed rock – layer of rock beneath soil
o Parent rock – rock formation that is the source of mineral fragments in soil
EROSION- process by which wind, water, ice, or gravity transports soil and sediment from one location to another
o Water
o Wind
o Gravity
o Waves
o Glacier
Unit 2 – Inside the Earth
LAYERS OF THE EARTH
 Crust – thin, solid, outermost layer of the Earth
o Continental crust
o Oceanic crust
 Mantle – layer of rock between the Earth’s crust and core
 Core – center of the Earth below the mantle
o Outer core – liquid
o Inner core – solid and dense
**The further you travel downward toward the core the more pressure, higher temperature.
PHYSICAL STRUCTURE OF THE EARTH
 Lithosphere – solid, outer layer of Earth that consists of the crust and the rigid upper part of the mantle, broken
into giant sections called tectonic plates
 Asthenosphere – the soft layer of the mantle on which the tectonic plates move
 Mesosphere – the strong, lower part of the mantle between the asthenosphere and the outer core
CONTINENTAL DRIFT THEORY – hypothesis that states that the continents once formed a single landmass, broke up, and
drifted to their present position
 Developed by Wegner
 Supercontinent called Pangaea
 Supported by the following evidence
o Fossils
o Climate
o Rocks
o Puzzle – like fi
SEA-FLOOR SPREADING – process by which new oceanic lithosphere forms as magma rises toward the surface and
solidifies
 Developed by Harry Hess
 Supported by the evidence of magnetic reversals
THEORY OF PLATE TECTONICS – theory that explains how large pieces of the Earth’s outermost layer, called tectonic
plates move and change shape
 Supported by Continental Drift Theory and Sea-Floor Spreading Theory
THREE TYPES
o Convergent Boundary – formed by the collision of two lithospheric plates
 Oceanic – oceanic – Indian Ocean – Earthquake
 Oceanic – Continental – forms a subduction zone – Ring of Fire – Volcanoes
 Continental – Continental – forms mountains – Himalaya Mount
o Divergent Boundary – formed by two lithospheric plates that are moving away from each other ex.
Atlantic Mid-Ocean Ridge – Mountain chain – forms new seafloor
o Transform Boundary – boundary between tectonic plates that are sliding past each other horizontally ex.
San Andreas Fault, CA causes many earthquakes
POSSIBLE CAUSES OF TECTONIC PLATE MOTION
 Ridge Push – at mid-ocean ridges, oceanic lithosphere sinks and move downhill
 Convection – hot rock rises, but cooler rock sinks
 Slab Pull – oceanic lithosphere is denser than the asthenosphere, the edge of the plate pulls the rest of the
tectonic plate with it
GPS has tracked the movement of the plates – move about 3 – 10 centimeters per year – very, very slow
DEFORMATION - process by which the shape of a rock changes because of stress
 Compression – when plates collide – convergent boundary
 Tension – when plates move apart – divergent boundary
 Folding – bending of rock layers due to stress
EARTHQUAKES – the shaking of the ground when rock breaks
 Elastic deformation – rock stretched to its limit – leads to earthquakes
 Plastic deformation – deforms rock like clay or a rubber band – does not lead to earthquakes
 Elastic rebound - sudden return of elastically deformed rock to its undeformed shape
SEISMIC WAVES – wave of energy that travels through the Earth away from the earthquake
 Body waves – travel through the interior of the Earth
o P-waves – Primary – 1st – pressure waves – fastest – slow down when they reach liquid – move in a backand-forth direction – (slinky)
o S-waves – Secondary – 2nd – shear waves – slower – stop when they reach liquid – move in a side-to-side
direction
 Surface waves – travel along Earth’s surface – most destructive – moves up-and-down and back-and-forthmoves more slowly that S-waves- moves the ground much like ocean waves
EARTHQUAKE MEASUREMENT
o Seismograph – instrument to measure vibrations from an earthquake
o Seismogram – the record or tracing of the vibrations from an earthquake
Epicenter – the point on the EARTH’S SURFACE directly above an earthquake’s starting point
Focus – the point INSIDE THE EARTH where an earthquake begins
MEASUREMENT SCALES
o Richter Magnitude Scale – developed by Charles Richter – 1 – 10 10 being the strongest
Measures the strength of an earthquake
o Modified Mercalli Intensity Scale – uses Roman Numerals I – XII (1 -12) XII being the most
intense – measures how much damage and to what degree people felt the earthquake
VOLCANOES – areas of the Earth’s surface through which magma and volcanic gases pass
TYPES OF VOLCANOES
o Shield – built by layers of lava during relatively quiet eruptions – broad bases, nonexplosive, not
very steep, but can be enormous – Mauna Kea in Hawaii
o Cinder Cone – built by layers of pyroclastic/cinder material – very steep sides, small, usually
erupt for a short time, erode easily, loosely packed, moderately explosive – Paricutin, Mexico
o Composite - most common type – form from alternating layers of pyroclastic, explosive and
lava, quiet eruptions – can be very explosive – broad bases, sides that get steeper at top –
Mount St. Helens, Mount Rainier, Washington State
LAVA – Explosive eruptions are caused by a high water and silica-rich content in the magma – this causes a low
viscosity (very thick, slow flowing) magma that often plugs the vents.
Non-explosive – little water or silica content – high viscosity – (thin, flows easily)
RING OF FIRE – outside edge of the Pacific Ocean – Most of the Earth’s 600 active volcanoes exist here, along the
plate boundaries (convergent).
HOT SPOTS – IN the middle of the plate, openings, not sure why they are there, Hawaiian Islands formed from
Hot spot.
Volcanoes can cause climate change – ash in atmosphere can block the sun and drop the global temperature.
Unit 3 - HYDROLOGY
OCEANS- 4 major oceans - Atlantic, Arctic, Pacific, & Indian
**Oceans are thought to have formed when volcanoes erupted and spewed ash and gases into the atmosphere. This
caused the Earth to cool and water vapor began to condense and caused torrential rains that filled up the deep basins.
WATER CYCLE - evaporation, condensation, precipitation, & runoff
71% of Earth's surface is water
 97% salt water
 1.9% glaciers, ice packs
 .8% ground water
 .3% available fresh water
Ocean water consists of salts and other dissolved solids - chlorine, sodium most of the salts. Oceans are salty because of
runoff carried to the oceans by rivers and evaporation.
OCEAN FLOOR  continental shelf - gently sloping section located between shoreline and continental slope
 continental slope - steeply inclined section between the continental rise and the continental shelf
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continental rise - gently sloping section located between the continental slope and the abyssal plain
abyssal plain - a large, flat, almost level area of the deep-ocean basin
mid-ocean ridge - a long, undersea mountain chain that forms along the floor of the major oceans
rift valley - a long, narrow valley that forms as tectonic plates separate
seamount - a submerged mountain on the ocean floor that is at least 1000 m high and that has a volcanic origin
ocean trench - a steep, long depression in the deep-sea floor that runs parallel to a chain of volcanic islands or a
continental margin
RESOURCES FROM THE OCEAN
 Living Resources
Fish
Seaweed
 Nonliving Resources
Oil
Natural Gas
Tidal/Wave energy
Minerals
 Desalination - process of removing salt from ocean water
OCEAN MOVEMENTS
 CURRENTS - streamlike movements of water
* Surface currents - caused by wind, Coriolis Effect, Continental Deflections
Ex. Gulf Stream - warm current - makes England's climate milder
Ex. California current - cold current - makes California's climate cooler in areas
* Deep Currents - caused by temperature and salinity/density
*Upwelling - process in which cold nutrient-rich water from the deep ocean rises to the surface
and replaces warm surface water
 WAVES – move in circular motion – caused by wind
 TIDES - caused by gravitational pull of the moon
 Tsunami – Giant wave that forms after a volcanic eruption, submarine earthquake, or landslide
 Storm Surge – a local rise in sea level near the shore that is caused by strong winds from a storm, such as a
hurricane
 EL NINO - change in the water temperature in the Pacific Ocean that produces a warm current
* causes - flooding on the west coast and drought in the southeast US
 LA NINA - change in the eastern Pacific Ocean in which the surface water temperature becomes unusually cool
* causes - drought on West coast and flooding in southeast US
Unit 4 WEATHER AND CLIMATE
ATMOSPHERE – mixture of gases that surrounds a planet or moon 78 % nitrogen 21% oxygen 1% other gases
Four Layers
 Troposphere – lowest layer of atmosphere, in which temperature decreases at a constant rate as altitude
 Stratosphere – layer of the atmosphere that is above the troposphere and in which temperature increases as
altitude increases
 Mesosphere – layer of the atmosphere between the stratosphere and the thermosphere and in which
temperature decreases as altitude increases
 Thermosphere – uppermost layer of the atmosphere, in which temperature increases as altitude increases
HOW THE SUN’S ENERGY IS TRANSFERRED IN THE EARTH’S ATMOSPHERE
 Radiation – energy transferred from the sun as electromagnetic waves – ex. Walk outside on a hot day – feel the
sun’s warmth on your face
 Thermal conduction – thermal energy transferred through a material – ex. You hold a cup of hot chocolate and
it warms your hands – pan on stove heats up because it touches the burner
 Convection – thermal energy transferred by the circulation/movement of a liquid or gas – ex. Boiling water
w/food coloring in it – the food coloring moves in a circular motion
GREEN HOUSE EFFECT – the warming of the surface and lower atmosphere of carbon dioxide, and other gases
absorb and reradiate thermal energy – the sun’s energy is trapped in the Earth’s atmosphere and cannot escape,
so, therefore the surface of the continues to heat up.
GLOBAL WARMING – a gradual increase in average global temperature
WIND – the movement of air caused by differences in air pressure/differences in temperature
 Global winds – combination of convection cells found at every 30° latitude and the Coriolis effect produces
patterns of air circulation
o Polar Easterlies – prevailing winds that blow from east to west between 60° and 90° latitude in both
hemispheres
o Westerlies – prevailing winds that blow from west to east between 30° and 60° latitude in both
hemispheres –prevailing winds for the United States
o Trade winds – prevailing winds that blow northeast from 30° north latitude to the equator and that
blow southeast from 30° south latitude to the equator
o Doldrums – the area where the trade winds meet at or near the equator and there is very little wind,
because of very warm air rising creates a very low pressure area
o Horse latitudes - 30° north and 30° south, sinking air creates a high pressure area, winds in these areas
are very weak – most of the world’s deserts are located in the horse latitudes because the sinking air is
very dry
 Local winds –
o Jet streams – narrow belts of high speed, strong winds that blow in the upper troposphere- do not
follow regular paths – North America has a jet stream that affects our weather and flight paths
o Mountain Breezes/Valley Breezes – day – warm air flows up the mountain side night – cool air moves
down the mountain slopes
o Sea Breezes/Land Breezes – day – land heats up air and air from the sea blows to land night – land
cools and air from land blow to the sea
AIR POLLUTION – the contamination of the atmosphere by the introduction of pollutants from human and natural
sources
 Primary pollutants – pollutants put directly into the air –ex. Dust, volcanic gases, ash , smoke from fires, and
pollen
 Secondary pollutants – pollutants that react when mixed with other primary pollutants – ex. Smog, acid
precipitation
Ozone – the protective layer in the atmosphere that protects the Earth from most of the Sun’s most harmful UV Rays
Has holes at present and is still thinning
Causes – CFC’s – in aerosol cans – legislation is protecting the ozone now.
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