Water Cycle Review
•Also called the hydrologic cycle
•The journey water takes as it circulates from the land to the air and back again.
•Involves evaporation, condensation, and precipitation.
•Repeats as a never-ending cycle
•Naturally occurring substances such a mineral, forest, water, and land that are used by humans.
•A resource that can be used repeatedly because it is replaced naturally (cycle).
•Water fits both these criteria.
•Basin-like land formation defined by highpoints and divides that descends into lower elevations.
•Carries water from the land after rainfall or snow melts.
•Drains all the water into a common outlet such as a stream channel, a reservoir, or bay
•Very low amounts of dissolved salt – less than 1%
•Ponds and Lakes
•Streams and Rivers
•Makes up 3% of Earth’s water resources, including ice caps and glaciers
•High concentrations of salt
•3.5% of the weight of seawater comes from dissolved salt (salinity)
•Makes up 97% of Earth’s water resources
•Water on the surface of the planet
•Ponds and Lakes
•Streams and Rivers
•Replenished by precipitation and groundwater
•More prone to pollution than groundwater
•Water found underground in cracks and spaces in soil, sand, and rock.
•Stored in and moves slowly through aquifers
•More than 50% of the people in the U.S. get their drinking water from groundwater.
•Largest use is irrigating crops
•Less prone to pollution
•Permeable – rock layers or sediments that transmit groundwater freely
a.Must include spaces (pores) throughout the rock layer
b.Pores must be connected
•Impermeable – few or no connected pore spaces, such as clay
•Zone of Aeration – region between the earth’s surface and the water table
•Water Table – the upper surface of the Zone of Saturation (can move up or down depending on rainfall)
•Zone of Saturation – region in the ground in which the pore spaces are filled with water
•Made of gravel, sand, sandstone, or limestone
•Water can move through these materials because they have large connected spaces (pores) that make them permeable.
•The flow of water depends on the size of the spaces and how well they are connected.
•An excavation or structure created in the ground by digging, which accesses groundwater in an aquifer.
•The well water is drawn by a pump that is raised mechanically or by hand.
•How is the well depth determined? What might make a well “go dry?”
•Replenished by precipitation
•A place in the ground where water flows up to the surface because of natural pressure without being pumped.
•Water comes directly from the aquifer or porous rock layer.
•Gravity creates the natural pressure.
•Contamination of bodies of water, often by human activity, which affects watersheds
•Occurs when pollutants are discharged directly or indirectly into the water.
•Along with air pollution, water pollution is the second biggest environmental concern.
Point Source Pollution
When the pollutants come from a single location such as dumping chemicals into a river.
Nonpoint Source Pollution
When pollutants are introduced into the environment over a large, widespread area such as agricultural runoff.
Types of Water Pollution
Surface Water Pollution
•Hazardous substances coming into contact with surface water
•Dissolves or mixes physically with the water
•Examples: Humans dumping trash into the waterways, especially objects that are swept down storm drains.
•Release of liquid petroleum hydrocarbons (oil) into the water
•Especially harmful to marine and other wildlife
•Usually localized, but can spread
•Examples: oil spills
Chemical Water Pollution
•Chemicals from industries and farmers that run off into the waterways.
•Examples: metals and solvents from industries
•Also, chemicals that control weeds, insects, and pests
•Pesticides and chemicals wash deep into the ground by rain water
•Can get into the aquifers, thus polluting the groundwater
•Anything on the surface can eventually work its way down to the groundwater.
•Plume – the area of groundwater affected by the contamination
•Look at the diagram and observe the amount of contamination in relationship to the point pollution.
Thermal Water Pollution
•The rise or fall in the temperature of a natural body of water.
•Changes the physical properties of water, particularly the amount of dissolved oxygen in the water.
•Decreases fish population and increases death to wildlife
•Sediments washing off fields are the largest source of agricultural pollution in the U.S.
•Sediments increase the cost of treating drinking water and can also clog fish gills, reducing their resistance to disease.
Overuse and Waste
•Irrigation uses 30% of all freshwater in the U.S.
•Swimming pools and water parks
•Watering the lawn
What other ways do you overuse or waste water where you live?
•Withdrawing groundwater causing the land to sink
•Causes flooding problems
•Causes a shift in the foundations of buildings, which can lead to their destruction
compare fresh and salt water, including examples?
identify the differences between surface and groundwater, including examples?
draw and label the parts of an aquifer?
recall six different types of water pollution?
generate ideas for reducing water pollution?
The H-R Diagram plots each star on a graph and measures the star's brightness (luminosity) against its temperature (color).
•Measured in Kelvin (K)
•Color of stars depends on their temperature
•The coolest stars – red
Hottest stars – blue
•Temperature increases from right to left, which is different than every graph you’ve probably seen.
•The amount of energy (light) a star emits
Tells us how bright an object appears from Earth
The measure of a star’s brightness as if it were at a standard distance of exactly 10 parsecs (32.6 light years) from the observer.
•Stars are classified by their spectra (the elements that they absorb) and their temperature.
•There are seven main spectral types (O, B, A, F, G, K, and M) listed in order of decreasing temperature.
•About 90 percent of the stars in the universe, including the sun
•Ranges from high to low luminosity and high to low temperature
•Color – ranges from red to blue
•Spectral Class M-O
•Medium size star
•Medium brightness and temperature
•Color – yellow
•Spectral Class G
•A red giant is a dying star.
•Our own sun will turn into a red giant star, expanding to engulf the inner planets.
•Color - reddish-orange hue
•High luminosity/ low temperature
•Spectral Class K-M
•They are the largest stars in the universe in terms of volume, although they are not the most massive.
•Color – reddish orange/blue
•High luminosity/low-high temperatures
•Spectral Class K-M, B-A
•A small very dense star that is typically the size of a planet
•Formed when a low-mass star has exhausted all its fuel
•Color – white
•Low luminosity/high temperature
Spectral Class B, O, A
•A small and relatively cool star on the main sequence
•Color – red
•Low luminosity/low temperature
•Spectral Class – M
1.Can you interpret the H-R Diagram?
2.Can you use the H-R Diagram to explain how stars are classified?
The two Documents below were read in class during the week of Dec 3.
•A disturbance that travels through space and matter
•Transfers energy, not matter
•Travel through electrical and magnetic fields
Examples: light, microwaves, radio waves, and X-rays.
•The highest point on a wave is called the crest.
•The lowest point on a wave is called the trough.
•The distance between successive crests or troughs
•Measures one complete wave
•The maximum extent of a wave measured from the position of equilibrium
•The number of crests of a wave that move past a given point in a given unit of time
•Measured in Hertz (Hz)
•Examples: FM/AM radio stations, stars
•Need close proximity to transmitter
•Examples: microwaves, routers, cell phones, stars
•“Infra” means below
•These waves are just below visible light
•Examples: remote controls, flames, lamps, stars
•All visible light
•Examples: light bulbs, fire, stars
•Often called “black light”
•Examples: sterilization, stars (sunburn anyone?), haunted houses
•High frequency waves
•Examples: see inside organisms, airport security, dentist office, stars
•Highest frequency waves
•Highest temperature (blue)
•Examples: radiation therapy (cancer), sterilization, stars
Studying the Universe
•Astronomers use all kinds electromagnetic waves to study the characteristics (temperature, energy, color) of stars.
•They can also use the EMS to determine chemical composition.
•A measurement technique which allows astronomers to see light that is absorbed, emitted, or scattered by materials
•How do we know what stars are made out of?
•Use the class set of absorption spectrums to determine which elements are present in each star.
•Astronomers can measure the distance of stars using a method called parallax.
•They measure the star twice per year.
•Every 6 months the Earth has moved nearly 186 million miles from it’s previous point due to its revolution around the Sun.
•Also called the Hydrologic Cycle
•Process by which water circulates between the Earth’s oceans, atmosphere, and land
•Involves water storage, evaporation, transpiration, condensation, precipitation, and runoff.
•Oceans – super storage for the water cycle - holds 96.5% of Earth’s water
•Primary pathway into the water cycle
•Oceans, seas, lakes ,and rivers provide nearly 90% of the moisture in our atmosphere through evaporation.
•Process by which water changes from a liquid to a gas
•Primary pathway that water moves from the liquid state back into the water cycle as water vapor
•Heat (energy) from the sun is necessary for evaporation to occur.
•Energy breaks bonds that hold water molecules together.
•Molecules move fast at boiling point 212o F
•Slow at freezing point 32o F
•Sublimation – the process of snow and ice changing into water vapor without first melting into water.
•Evapotranspiration – water lost to the atmosphere from the ground surface and transpiration of groundwater by plants through their leaves.
•Superhighway used to transport water around the globe
•Involves condensation and precipitation
•Process in which water vapor in the air is changed into liquid water.
•Loss of energy allows water molecules to bond.
Forms clouds, fog
•Water released from clouds in the form of rain, freezing rain, sleet, snow and hail
•Provides the delivery system of atmospheric water to the Earth
Ice, snow, groundwater
•Water locked up in its present state for a relatively long period of time
•Involves runoff and infiltration
•Precipitation that did not get absorbed into soil, or evaporate
•Ice caps and glaciers - provides runoff from melting
•Water moved by gravity makes its way into places that collect water – rivers, lakes, ponds, ocean
•The downward process of moving water from the land surface into soil or porous rock
•Groundwater - Large amounts of water stored in the ground
•Aquifer – another name for groundwater, usually describes water bearing formations
•The area of land where all the water that falls in it and drains off of, goes into the same place
•Can be as small as a footprint or as large as all the land that drains water into the Mississippi River
Science 7: Apply scientific principles to design a method for monitoring and minimizing a human impact on the environment. Take the Carbon Footprint Challenge at Home! http://www.footprintcalculator.org/
Human Impacts on the Environment: www.khanacademy.org/science/biology/crash-course-bio-ecology/crash-course-ecology-2/v/crash-course-ecology-10
Science 8: Light Waves
•The part of the electromagnetic spectrum, between infrared and ultraviolet, that is visible to the human eye.
•Shorter waves – higher frequency and energy
•Longer waves – lower frequency and energy
Visible Light Spectrum
•Produced when light passes through a prism, slowing the wavelength into each separate color.
•ROY G. BIV - red, orange, yellow, green, blue, indigo, violet
•We see these waves as the colors of the rainbow.
•Each color has a different wavelength and frequency.
•Red has the longest wavelength and shortest frequency
•Violet has the shortest wavelength and highest frequency.
•Seen together, they make white light.
•For an object to be visible it must produce its own light or reflect light.
•Produces own light - Sun, candle, flashlight
•Reflects light - Moon, mirror, glass
•Opaque – A material that reflects or absorbs all of the light that strikes it. (wood, metal, cardboard)
•Transparent – transmits light (glass, water, air)
•Translucent – scatters light as the light passes through (wax paper, frosted glass)
How light travels
•Light travels in straight lines.
•This straight line motion can be:
•Occurs when parallel rays of light hit a smooth surface.
•All the rays are reflected at the same angle.
•Law of reflection: the angle of reflection equals the angle of incidence.
•Angle of incidence - measure of the angle of a ray to the surface normal (90o to the surface)
•When parallel rays of light hit a bumpy surface.
•Each ray obeys the law of reflection, but each ray hits the surface at a different angle.
The light is scattered.
•When light waves enter a new medium at an angle, their speeds changes.
•The change in speed causes them to bend, or change direction.
•Index of Refraction – a measure of how much a ray of light bends when it enters that material
•When light traveling in straight parallel lines passes through an object that is curved like a lens, the light is refracted at different angles.
•Convex or converging lenses bend light toward a central focal point.
•Concave or divergent lenses bend light outward away from a focal point.
•Light does not pass through or reflect from material, but remains in the material as energy.
•What happens to the black surface?
Color of objects
•Color – Objects reflect colored light that is not absorbed.
•We see objects color as the reflected color.
Colors of Light
•Red, Blue and Green
•When combined in equal amounts, primary colors produce white light.
•If combined in varying amounts, they can produce any other color.
•Yellow, Cyan and Magenta
•Primary colors combined in varying amounts
•Complementary - form when a primary color and a secondary color combine to make white.
•Yellow and blue = white
•Y + B = W or R + G + B = W
•A relative expression of the intensity of the energy output of a visible light source
•Brightness is determined by the light wave’s amplitude.
•The greater the amplitude, the brighter the light.
•Distance from light source also affects brightness.
•Chemical and physical breakdown of rocks into sediment
•Occurs when the rock’s environment changes and the rock is exposed to some form of water and the air
Chemical change within the rock’s minerals breaking down the bonds holding the rocks together, causing them to fall apart into smaller pieces.
Causes rock to break:
•(A) Oxidation – Iron combines with oxygen making rust.
•(B) Hydrolysis – Water softens minerals in rocks.
•(C) Carbonation – Carbon dioxide in rain water creates carbonic acid. Ex. acid rain, cave creation
Physical (Mechanical) Weathering
The process that breaks rocks apart without changing their chemical composition caused by:
•(A1) Abrasion - by rapidly moving water, glaciers or wind.
•(A2) Ice wedging - by freezing and thawing (contracting and expansion).
Causes rock to break:
•(B) Plant Roots - grow into cracks and break apart rock.
•(C) Burrowing – animals scrape and dig the terrain.
•(D) Temperature Change- cold to hot expanding and contracting.
•(E) Gravity - falling rocks or debris, compression
The process that moves bits of rock or soil from one place to another by:
•Water (rivers, waves)
The process in which sediments, soil, and rocks are added to a landform such as:
Occurs when the forces moving sediments are no longer able to overcome the forces of gravity and friction.
Running water is the primary agent of erosion.
•Velocity (speed) depends on gradient (slope) and discharge (amount of water).
•As velocity increases the size of particles carried also increases.
Ages of Rivers
•(A) Young Rivers - fast-flowing,
V-shaped valleys, waterfalls, and rapids
•(B) Mature rivers – Less energy, slower, meanders (1), sandbars
•(C) Old River – Very slow, shallow, large amounts of sediment deposited, many narrow channels, islands, deltas (2)
Features Created by Wind
Caused by abrasion from wind blown sand.
Features Created by Gravity
Gravity shapes the Earth’s surface by moving weathered material from a higher place to a lower one.
•(A) Landslides (fast)
•(B) Mud flows
•(C) Slump/creep (slow)
Features Created by Glaciation
Caused as massive glaciers flow down hill bulldozing existing rocks.
Features Created by water (waves)
Erosional and depositional features which form along coastlines
•The western U.S. coastline has more erosional features.
•The eastern U.S. coast and the Gulf of Mexico has more depositional features.
Ecoregions of the United States
Areas defined by its environmental conditions, especially climate, landforms, and soil characteristics.
Ecoregions Environmental Conditions
•Climate – weather conditions in an area over time.
• Landforms – crustal material
•Mountains – high elevation
•Plateaus – medium to high elevation
•Plains – low elevation
•Amount of vegetation
•Dry (arid) – very little vegetation (poor soil)
Humid – large amount of vegetation (good soil)
Examples of Ecoregions
•Subtropical (Florida, South Eastern States)
•Tundra (N Alaska)
•Temperate Steppe (Great Plains
•Marine Mountains (Coastal Washington and Oregon)
•Desert and Desert Mountain (Nevada and parts of New Mexico)
What determines how the processes of weathering, erosion, and deposition work to reshape Earth’s surface?
•Vibrations that travel through the air or other media
•When these vibrations reach the air near your ears you hear the sound.
How Sound Travels
•Sound waves carry energy through a medium (solid, liquid or gas) without the particles of the medium traveling along.
•Sound travels as a longitudinal wave.
How Sounds are Made
•Longitudinal waves are generated when a source of energy forces the matter in a medium to vibrate.
•This back-and-forth motion pushes air particles together, generating a compression, or moves the particles apart, generating a rarefaction.
•Sound waves must have a medium to travel through.
•Gas – air is the most common
•In outer space there are no molecules to compress or rarefy, so sound does not travel through outer space.
Speed of Sound
•Depends on the physical properties of the medium it travels through.
•At room temperature, sound travels through air at about 342m/s.
Physical Properties of Media
•Elasticity – the ability of a material to bounce back after being disturbed
•Solid materials are usually more elastic than liquids or gases.
•Particles of a solid do not move very far, so they bounce back and forth quickly as the vibration travels through the object, which allows waves to move faster.
•Density – how much matter there is in a given amount of space
•The speed of sound depends on how close together the particles of the substance are in the medium.
•Temperature - degree or intensity of heat present in a substance or object
•In a given media (solid, liquid, gas), sound travels more slowly at lower temperatures.
Properties of Sound Waves
•Intensity – the amount of energy the wave carries per second through a unit of area
•Amplitude increases with increased energy
•Measured in watts per square meter (W/m2)
•Loudness – describes what you actually hear.
•Though not the same as loudness, the greater the intensity of a sound wave, the louder it is.
•Measured in decibels (dB)
•Maximum safe level is 85 dB
Frequency – the number of vibrations that occur per second
Wavelength changes with frequency
Measured in Hertz (Hz)
50Hz = 50 vibrations per second
•Pitch – a description of how high or low the sound seems to a person
•High frequency = high pitch
•Low frequency = low pitch
•Example: a young girl might have a squeaky (high pitched) voice, an older man might have a deep (low pitched) voice
•The apparent change in frequency as a wave source moves in relation to the listener
•Sounds moving toward a person – Waves are at a higher frequency, so pitch appears to increase (high)
•Sound moving away from a person – Waves are at a lower frequency, so pitch appears to decrease (low)
A model that describes the formation, breakdown, and reformation of a rock.
•Formed when sediments accumulate and compact and cement together.
•Often deposited in layers and contain sand, pebbles, and frequently fossils.
Ex. sandstone, limestone
Physical properties of Sedimentary Rocks
•Sand, pebble, and even boulder size particles
•Some may contain fossils
By what process are sedimentary rocks broken down?
•By weather (rain, ice, wind), chemical changes, and living things (plant).
•Creates lose material called sediments.
By what process are sediments moved?
They are deposited in layers - Deposition
What are the processes that form sedimentary rock?
Sediments are deeply buried, placing them under pressure because of the weight of overlying layers.
•New minerals stick the sediment together just like cement.
•This holds the grains together tightly.
•Formed by heat and pressure while buried deep below Earth’s surface.
•Have a layered or banded (ribbon like) appearance or may have crystals.
Ex. Gneiss, Marble, Slate
Physical Properties of Metamorphic Rocks
•Layers look like ribbons
What are the processes that form metamorphic rock?
Heat (caused by magma)
•Temperatures high enough to change its structure but not to melt it.
•Heat can change sedimentary, igneous, or another older metamorphic rock.
Pressure - Caused by intense collisions and friction of tectonic plates and pressure from overlying rock layers.
•Deep under the Earth’s surface.
•Pressure can change sedimentary, igneous or another older metamorphic rock.
•Formed when lava or magma harden.
•Found near volcanoes or fissures
•Ex. Basalt, Obsidian, Granite
Physical Properties of Igneous rock
Fast Cooling Slow Cooling
Glassy Large crystals
Holes where gas was trapped Many colors
What are the processes that form Igneous rock?
•Caused by increase in temperature in rock deep below the surface of Earth
•Caused by friction between crustal plates
Lava –molten rock material on Earth’s surface.
Magma – molten rock material under Earth’s surface.
What are the processes that form igneous rock?
Cooling and Hardening
•Melted rock turns solid.
•Slow cooling happens below Earth’s surface as magma cools forming large crystals. Ex. granite
•Fast cooling happens on the Earth’s surface as lava cools forming small crystals. Ex. obsidian, basalt, pumice
Video Resource: https://drive.google.com/file/d/0BxOms4hIDvR3TmxEcHJWV2xzTkU/view
Similarities of Rocks and Minerals
•Inorganic compounds (non-living)
•Both can be classified by their chemical composition.
•Found around the world in many of the same places on Earth
•Most commonly classified by how they form.
•Composed of more than one mineral.
•No definite chemical composition.
•No definite crystal structure.
In addition to being inorganic, solid, and naturally formed like rocks, minerals also have:
•A definite chemical composition. (amounts of elements present)
•A definite crystal structure. (unique arrangement of atoms/molecules)
Mineral Identification – Important Vocabulary
1.Color (green, red, yellow, blue, etc.)
2.Streak (Color of the streak across a streak plate)
3.Luster (Metallic or Non-Metallic)
4.Hardness (Mohs Scale)
5.Density (Specific gravity)
6.Breakage Pattern (Cleavage and Fracture)
•Many minerals have distinctive colors, but they come in a variety of hues.
•Color should never be used as the only test for identifying a mineral.
•The color a mineral displays in a finely powdered form
•Might be completely different from the color of the mineral itself
•To determine the streak, rub the mineral across a piece of unglazed porcelain know as a streak plate.
•The way a mineral’s surface reflects light.
•Two types of luster
•Metallic – shiny like a metal
•Nonmetallic – several kinds
1. Glassy - quartz
2. Pearly - talc
3. Greasy - graphite
4. Silky – gypsum
5. Resinous - sulfur
6. Adamantine - diamond
•One of the most reliable ways to identify minerals
•Compares the resistance of a mineral to being scratched by 10 reference minerals
•Called the Mohs Hardness Scale
•Named after Friedrich Mohs, a German mineralogist, who developed the scale in 1812
•Defined as the amount of matter per unit volume
•Density = mass divided by volume
•In minerals, the term specific gravity is used in describing density.
In this way minerals can be compared and identified.
•Refers to the way some minerals break along certain lines of weakness in their structure
Mica is a good example.
•A description of the way a mineral tends to break
•Some different types of fracturing
1. Conchoidal – smooth curve
2. Hackly – sharp jagged edges
3. Uneven – rough and irregular
4. Fibrous – shows fibers
Some minerals are cut to become precious gemstones.
Erik E. Mason