Praxis Review for Earth Science By Frank H. Osborne, Ph. D. Kean University Union, New Jersey...

Praxis Review for Earth Science

ByFrank H. Osborne, Ph. D.

Kean UniversityUnion, New Jersey

[email protected]

Compiled and expanded by Suzanne Leone, Raleigh NC (2012)

(C) 2003-2012 Frank Osborne PhD 1

mailto:[email protected]

2


by Frank H. Osborne, Ph. D.

Earth Materials and

Surface Processes

23-27 questions

(C) 2003-2012 Frank Osborne PhD

3

Earth Materials

Minerals•A mineral is a naturally occurring substance with characteristic physical and chemical properties. •Nearly all rocks are composed of minerals.•Polymineralic rocks are composed of more than one mineral, ex. granite.•Monomineralic rocks are composed of only one mineral, ex. limestone.


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Earth MaterialsMineral CompositionMinerals are composed of elements. • Some minerals contain only one element (Ex: copper, sulfur

and graphite (carbon)).• Most minerals are made up of only a few elements.• Oxygen is the most common element by weight and volume.

Silicon is second most abundant by weight.

These eight minerals form most rock: amphibole, biotite, muscovite, olivine, orthoclase, plagioclase, pyroxene, and quartz


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Earth MaterialsProperties of Minerals

Differences in properties are used to categorize and identify minerals.• Minerals have a characteristic crystalline

structure, in many cases the silicon-oxygen tetrahedron.

• The most basic characteristics are perceived through observation and polarizing microscopy


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Earth MaterialsProperties of Minerals

Color – this varies depending on the chemicals present and is the least informative in identifying a mineral

Luster – what the surface looks like in the light

Specific Gravity – how heavy it feels, its heft (weigh in known beaker of water)

Cleavage – the pattern when broken; planes or conchoidal

Fracture - the shape and texture of the surface formed when a mineral is broken(C) 2003-2012 Frank Osborne PhD


Earth Materials

Mohs Hardness Scale (1812)

Properties of Minerals, continued

Crystal Form – shape of crystal, shape the mineral would take if it had room to grow in a cavity – some minerals have a number of different crystal shapes

Tenacity – toughness, how cohesive the mineral is, if it falls apart

Hardness – what it can scratch and what scratches it (see graph)


Earth MaterialsProperties of Minerals, continued

Transparency - the ability to transmit light. • Depending on a number of things,

rocks & minerals can also transmit light. Many rocks that are opaque when in a chunk, are translucent when cut into very thin slices.

• Gems stones are often valued on how clear, or transparent they are.


Earth MaterialsSpecial Properties of Minerals

Magnetism

Chatoyancy (optical reflectance effect seen in certain gemstones. Coined from the French "œil de chat," meaning "cat's eye“)

Fluorescence (emit visible light when exposed to ultraviolet light)

Odor (sulfur and sulfides-egg; arsenic-garlic; wet clay)

Streak color (when rubbed on a streak plate; non-white minerals only)

Flame color (when burned and viewed with a spectroscope)

Conductivity

Alkalinity (the use of hydrochloric acid on sulfides or carbonates like limestone to liberate CO2 bubbles)


Rock Formation• Rocks are classified by the processes under

which they were formed. • All rocks begin as igneous rocks, and are then

transformed into metamorphic or sedimentary rocks.

• One or more minerals make up each rock.


Rock FormationThe Rock Cycle relates the three types of rocks. The rock cycle is driven by interactions between plate tectonics and the hydrologic cycle.


Earth Materials

The Rock Cycle• Any one rock type can change into any other

rock type.• There is no preferred direction of movement of

materials in the rock cycle for any one mass of material.

• There is no exact point of separation between the rock types.


Earth Materials

The Rock Cycle• Sedimentary rocks often contain sediments or

fragments which have varied origins.• The composition of some rocks suggests that

the materials in the rock (the sediments or minerals) have undergone multiple transformations within the rock cycle.


Weathering and ErosionWeathering is the breakdown of rocks to form particles called sediment.• Physical weathering is the breakdown of rock

without chemical changes− Freezing and thawing (frost action)− Thermal expansion and contraction

• Chemical weathering is the breakdown of rock by chemical action

− Oxidation− Hydration− Solution by acids


Weathering and ErosionFactors affecting weathering are:• Exposure – more exposure means faster weathering

• Particle size – the smaller the particles, the greater the surface area

• Mineral composition – some minerals (quartz) are more resistant to weathering than others (mica and feldspar)

• Climate – warmth and moisture enhance weathering


Weathering and Erosion

Erosion is the process by which sediments are obtained and transported.• Transporting agents include water (streams),

glaciers, waves, density currents in water, wind, and people.

• Driving forces include gravity and change of potential to kinetic energy.


Weathering and ErosionStream Erosion

Stream water carries sediments.• Dissolved minerals are carried in solution.• Small solid particles are carried in suspension.• Large solid particles are moved by rolling or

bouncing along on the bottom of the stream.

The ability to carry sediment depends on velocity. Stream velocity depends on the gradient (slope) and discharge (volume) of the stream. On a curve, it is fast on the outside and slow on the inside.


Weathering and ErosionStream Erosion


Hubbard Glacier, Alaska

Weathering and ErosionWind Erosion• When wind carries sediment, it

forms dunes.

Glacial erosion• A glacier can carry large amounts of dirt.• When the glacier stops moving,

it drops the dirt, forming a moraine.

abc-of-mountainbiking.com

http://www.abc-of-mountainbiking.com/europe/portugal/leiria/thewestcoast.asp


Weathering and ErosionGlacial Erosion• There is a moraine in New

Jersey left over from the last ice age.

• The same glacier also formed Long Island.


SoilSoil is a product of weathering and erosion.

Soil Types• Residual soil forms from the weathering of rocks

nearby.• Transported soil is brought in by erosion.

Soil layers develop over as much as 1,000 years. Soil generally tends to reflect the composition of the rocks below, plus decomposed organic matter.

Erosion can also destroy nutritive soil (hūmus).


SoilA soil horizon is a vertical layer of soil with certain characteristics.• “Lower” horizons result from

weathering

humus–uniformly dark, spongy, jelly-like, organic matter that will break down no further

topsoil – The uppermost 15-20 cm of dirt; includes humus and various amounts of sand and clay

eluviation layer – the layer where dissolved or suspended material is moved down or sideways when rainfall exceeds evaporation

subsoil – a layer of material that is breaking down into soil; similar in texture to compost

regolith – a layer of loose, heterogeneous mineral material covering the bedrock.

bedrock – solid, unweathered rock


DepositionDeposition is also known as sedimentation.

Deposition occurs when the velocity of water, wind or other erosional system decreases.

Deposition depends on:• Particle size--heavier particles sediment faster• Shape--spherical particles sediment faster• Density--denser particles sediment faster


Deposition & SedimentationRock layers are formed by sediments. The particle size determines the rock type.

Boulders, gravel, pebbles --> conglomerateSand --> sandstoneSilt --> siltstoneColloids, clay --> shaleColloids, chemical sediments --> limestone


DepositionDeposition by moving water• When a river enters the ocean,

the velocity decreases.• Sediments are deposited

and form a delta.• Ex: Mississippi River Delta.

http://www.sln.org.uk/geography/schools/blythebridge/gcseriversrevisionlc.htm






Rock FormationRocks are the solid material that makes up the Earth. There are three types:• Sedimentary Rocks--formed by solid sediments

weathered from pre-existing rocks

• Igneous Rocks--formed by cooling of liquid rock

• Metamorphic Rocks--formed by transformation of igneous or sedimentary rocks by reheating or pressure


Sedimentary Rock Formation• Cementation--larger particles

are cemented by minerals precipitated out of the water

• Compression--very small particles are compressed by immense weight of water and sediment layers above them; aka compaction

• Chemical action--ionic materials precipitate out of the water

• Biological processes—precipitation of minerals by biological organisms (molting, elimination)


Sedimentary Rock Properties• contain one or more sediments• may have organic origin (example: coal)• form layers called strata • frequently contain fossils

Particles of sedimentary rocks resemble the sediments they came from.

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Types of Sedimentary Rocks

Three major groups of sedimentary rocks:• Detrital rocks form from sediments washed in

by water, such as gravel, sand and mud. Ex: sandstone, shale.

• Chemical sedimentary rocks have crystalline texture. Ex: limestone, dolostone, gypsum, salt

• Biochemical sedimentary rocks: clastic (limestone from shells), chert, coal


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Igneous Rock Properties• non-sedimentary in origin• form by solidification or crystallization of liquid

rock called magma • Longer cooling time causes big crystals in the

rock. Shorter cooling time causes small crystals in the rock.

• Texture depends on the size of the crystals.• Along with composition, texture is an important

identifier.(C) 2003-2012 Frank Osborne PhD

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Igneous Rocks

Bowen’s reaction series accounts for the crystallization of intermediate and felsic magmas from an original basaltic (mafic) magma over time.

high in Mg and Fe

high in Al and SiHigher temperature magma tends to originate deeper.

Density and dark color decrease with temperature.(C) 2003-2012 Frank Osborne PhD

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Examples of Igneous Rocks

• granite• pumice• scoria• gabbro• basalt

• rhyolite• dacite• andesite• obsidian


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Metamorphic Rock Properties• non-sedimentary in origin.• a response to heat and pressure within the Earth’s

crust (from plate collisions, mountain building and sometimes localized heating such as with volcanic eruptions)

• form from recrystallization of pre-existing rocks• often show banding where like crystals are arranged

in layers• a distorted structure caused by curving and folding

of the bands (they look funky!)(C) 2003-2012 Frank Osborne PhD

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Types of Metamorphic Rocks

• Foliated rocks have crystals arranged in parallel planes. Examples: slate, schist, gneiss.

• Nonfoliated rocks do not have a preferred orientation among their minerals. Examples: marble, quartzite, greenstone.


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Metamorphic Rocks

Regional metamorphism• occurs over a wide area

• gradation from low to high metamorphism depending on the levels of temperature and pressure involved.


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Metamorphic Rocks - Gneiss

Steps leading to the formation of gneiss• Most gneiss begins with recrystallization of clay-

rich sedimentary rocks during regional metamorphism.

• Gneisses are composed mainly of quartz and/or feldspar, which cause the light bands.

• The dark bands come from biotite and hornblende.


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Metamorphic Rocks - Marble

limestone CaCO3 --> limestone marble

dolomite CaMg(CO3)2 --> dolomite marble

Limestone marble reacts with the acid test.

Dolomitic marble also reacts with the acid test, but it must be powered first.


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Civilization and Earth Materials

Minerals are used in a variety of human activities.• Humans use fossil fuels for the major part of their

energy needs. These include coal, oil and natural gas.

• Rocks are quarried and used as building stones and pavement.

Earth resources are not renewable. They cannot be restored easily in your lifetime.


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Landscape development

Landscapes are the features of the surface of Earth.• slope of the land

• shape of surface features

• stream drainage patterns

• stream slope

• soil characteristics


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Landscape development

• Landscape characteristics can be measured using actual observations, maps, aerial photographs or satellite images

• Gradients, slopes and profiles are given on topological maps (contour maps)

• Major landscape types are mountains, plateaus and plains


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Landscape developmentLeveling forces break down rocks and transport material on the Earth’s surface.

• Weathering – the breaking down of materials through contact with the Earth's atmosphere, organisms, and waters

• Deposition – process of adding transported material to a landform

• Erosion – the removal of weathered rock materials from their source area

• Mass wasting – the downslope movement of rocks, sediments, or soil under the influence of gravity (landslide)

• Subsidence – a lowering of a region of land caused by forces in the crust or by tectonic interaction

• Uplift – a raising up of a region of land caused by forces in the crust or by tectonic interaction(C) 2003-2012 Frank Osborne PhD

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Landscape development• Glaciers produce U-shaped valleys and deposit

soil with a wide range of particle sizes.

• Streams may be seasonal in arid climates, or have internal drainage where streams deposit water into a basin rather than leading to the ocean. Ex: Great Salt Lake, Utah (C) 2003-2012 Frank Osborne PhD

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MapsGeologic features can be represented by

photographs, as well as topographic and geological maps.

Maps are interpreted using distance scales, and colors to represent features.

Topographic maps indicate locations of equal altitude using contour lines. The distance between lines shows the grade of a slope.

Geologic maps use colors and symbols to represent rock ages and structures.


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Landscape developmentNatural factors • Bedrock greatly influences the landscape above it.

Stream drainage patterns indicate information regarding the contour of the bedrock below.

• Different types of rock have different degrees of resistance to weathering and erosion.

• Climate affects the rate of change of a landscape. Warmth and moisture accelerate erosion.


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Landscape developmentHuman factors• Removal of forests for development leads to

accelerated erosion of soil when it rains.

• Acid rain causes increased chemical weathering of rocks. Example: accelerated erosion of limestone.

• Environmental conservation can help conserve limited natural resources.


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Natural HazardsPeople live in risky places.

A flood plain can fill up with water and carry away the work of generations.

Seismic hazards are issues near faults, such as the San Andreas Fault.

It is not a good idea to live on the slopes of a an active volcano, yet people live near Mt. Etna.


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Tectonics and Internal

Earth Processes

18-22 questions



Plate Tectonics

Plate tectonics is a unifying theory of Earth Science.

It can explain events of the past, the present situation, and it can predict what will happen in the future.• Formation of mountain ranges• Continental drift and sea-floor spreading• Ocean bottom is younger than continents• Magnetic field reversals


Plate Tectonics

• Plates move as a result of convection currents in the mantle.

• Plates generally move about an inch or two per year, about as fast as your fingernails grow.

• Plates can spread apart, collide or slide next to each other.

• Plate boundaries are known for presence of volcanoes and earthquakes.


Tectonics (from L. Latin tectonicus, from the Greek τεκτονικός "pertaining

to building") is a scientific theory that describes the large scale motions of Earth's lithosphere, the rigid outermost shell of a rocky planet.

On Earth, the lithosphere comprises the crust and the portion of the upper mantle that behaves elastically on time scales of thousands of years or greater.

Plate Tectonics History & Evidence


One of the main points of the theory: The amount of surface of the (continental and oceanic) plates that disappears in the mantle along the convergent boundaries by subduction is more or less in equilibrium with the new (oceanic) crust that is formed along the divergent margins by seafloor spreading.

Just as much is cooled as gets subducted.



Plate Tectonics History & Evidence1596 – A. Ortelius hypothesized that continents 'drift'

1912-15 – meteorologist, A.Wegener, fully described what he called continental drift in his book, The Origin of Continents and Oceans

1925 – Wegener matched the continental edges of South America and South Africa based on continent shape, rock formations and fossil content, confirmed in 1954

1956-88 – K. Runcorn constructed apparent polar wander paths for Europe and North America that presume a previous plate configuration, confirmed in 1981


Snider-Pellegrini_Wegener_fossil_map.svg



1947 - Elsasser developed geomagnetic field theory (there are convective motions in the fluid iron core), aka “dynamo theory”, confirmed in 1958 by Bullard

1950’s – Many scientists measured alternating marine magnetic polarities in ≈100 ty cycles (paleomagnetism)

1968 – Mid-Atlantic ridge core sample dating confirmed the sea floor is spreading

http://www.plainedgeschools.org/swells/plate_tectonics.htm


http://www.plainedgeschools.org/swells/plate_tectonics.htm


Plate Boundaries (USGS)


Plate tectonic maps and Continental drift animations

by C. R. Scotese,PALEOMAP Project (www.scotese.com)

Scotese, C. R., 2001. Atlas of Earth History, Volume 1, Paleogeography,PALEOMAP Project, Arlington, Texas, 52 pp.

Click to view animation of the past 200 m.y.!

http://www.scotese.com/pangeanim.htm






Plate Tectonics• Divergent plates spread apart at a

spreading center. Ex: mid-Atlantic ridge

• Convergent plates are colliding. Mountain ranges will form as a result of the collision. Ex: the Himalayas formed by India colliding with Asia.

• Transform boundaries are found where plates slide together. Ex: the San Andreas Fault.

cimss.ssec.wisc.edu

pacificislandtravel.com

San Andreas Fault offsets an orchard!

http://cimss.ssec.wisc.edu/sage/geology/lesson2/concepts.html

http://www.pacificislandtravel.com/nature_gallery/mountains.htm

http://www.tommcmahon.net/2008/10/the-san-andreas.html

http://www.tommcmahon.net/2008/10/the-san-andreas.html


Plate Tectonics• Continental crust is less dense than ocean

bottom. • At a convergent boundary between the two, the

ocean bottom is drawn under the continent. This is called subduction.

• About 50-75 miles into the continent a line of volcanoes will form.

• If the subducted ocean bottom is bringing lots of water with it, the resulting steam will make the volcanoes active.


Plate Tectonics•When a subduction zone is found under the ocean, a trench forms. Ex: Puerto Rico Trench.•A spreading center located in a continent is called a rift valley. Ex: Great Rift Valley in East Africa.•Sea-floor spreading moves the plates. Ex: At the mid-Atlantic ridge, Europe and Africa are moving away from the Americas.


Plate Tectonics

• A hot spot is a point where a hole has been melted through the crust from the mantle.

• The hot spot stays in one place while the crust moves along over it. Ex: Hawaiian Island chain, Yellowstone National Park (caldera).

• Plate activity results in earthquakes and volcanic activity.

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Plate TectonicsThe Ring of Fire is a series of volcanoes that

surrounds the Pacific Ocean.



Crust Deformation Processes

Extension is a stretching process. Such a process is apparently occurring in the Basin and Range area of the western United States.

Divergent boundaries

create rifts (on land)

and mid-ocean ridges (on the ocean floor)



Compression is a squeezing process. This is generally associated with mountain building.

Convergent boundaries

create folds and mountains

and trenches (on the ocean floor)



Shear results from two portions of crust passing by each other. Example is the San Andreas fault.

Transform boundaries

create faults


Crust Deformation Processes• The Pacific coast mountain ranges resulted from the

collision of the North American Plate with the Pacific Ocean Plate. Volcanoes in Washington and Oregon indicate that there is a subduction zone under the Pacific northwest.

• Eastern mountains in the United States were produced by a collision between North America and Africa. The resulting mountains were once as high as the Himalayas; erosion from wind, water and glacier caused the mountains to appear the way they do today.


rubymountainphotography.com

Crust Deformation ProcessesWestern mountains in the United States display block faulting. It is suspected that the continent is stretching apart in the west. The process of extension causes separation of the crust, and blocks will drop down as a result. (These are tilted.)

Similar block faulting occurred when the Atlantic Ocean began to open. This resulted in such features as Narragansett Bay and the Newark Basin.

http://www.rubymountainphotography.com/Great-Basin-1/Faulting/13726386_YGWLR/1/1003510540_y4YmQ


Isostasy

Isostasy refers to the fact that thicker continents (such as Africa) ride higher on the mantle than do thinner continents.When large amounts of sediment are deposited on a particular region, the immense weight of the new sediment may cause the crust below to sink. When large amounts of material are eroded away from a region, the land may rise to compensate.

An iceberg always floats with a certain proportion of its mass below the surface of the water, sinking or rising to maintain that proportion as more ice is added or removed. Likewise, the Earth's lithosphere "floats" in the asthenosphere.


Earthquakes and How they Provide Information about the

Structure of the EarthEarthquakes• An earthquake is a sudden motion of rocks in

the crust of the Earth after a long buildup of potential energy.

• Intensity is recorded by a seismometer on the Richter scale which is logarithmic. This means that a 6 is ten times stronger than a 5.


Earthquakes• Earthquakes are caused mostly by rupture of

geological faults, but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests.

• An earthquake's point of initial rupture is called its focus or hypocenter.

• The epicenter is the point at ground level directly above the hypocenter.

http://curriculum.kcdistancelearning.com/courses/ENVSCIx-AP-U10/a/unit05/apes_5.c.4.html

http://curriculum.kcdistancelearning.com/courses/ENVSCIx-AP-U10/a/unit05/apes_5.c.4.html


Seismic Wave Evidence

There are two types of seismic waves• P waves (primary, parallel, “push”) – can

propagate through a liquid, compression type• S waves (secondary, perpendicular, shear, slower,

“sideways”) – cannot propagate through a liquid, longitudinal type

The precise amount that a seismic wave bends and their velocity while traveling through Earth's interior depend on conditions such as composition, density, etc., in Earth's interior.


Seismic Wave Evidence

Therefore seismic waves that have passed through Earth's interior (from a seismic event) tell geophysicists about the interior structure and composition.•The outer core of the Earth is believed to be liquid because S waves do not pass through it and P wave velocity is sharply decreased.•Using similar techniques, oil companies use seismic waves to locate bodies of liquid petroleum under the surface of the Earth.


Locating the Epicenter• To locate the epicenter of an earthquake,

geologists use three seismographs in widely separated locations.

• The time interval between the P and S waves gives the distance of the epicenter from the observatory. A circle with this radius is drawn on a map or globe.

• The same is done with all three stations. There is one point that lies on all three circles and it is the epicenter. (This process is called triangulation.)

Distribution of Earthquakes (geology.csupomona.edu)

http://geology.csupomona.edu/


Structure of the EarthThe Earth is a series of concentric layers.

• The crust (lithosphere) is the outer layer of the Earth. Continental crust is light and granitic. Ocean bottom crust is dense and basaltic.

• The upper mantle (asthenosphere) contains cooler liquid rock that has very slow convection currents, which cause continental drift.

• The outer core is made of molten rocks as well as iron and nickel.

• The inner core is a solid ball of iron and nickel.

Earth_internal_structure.png

http://en.wikipedia.org/wiki/File:Earth_internal_structure.png


Electricity and Magnetism

Magnets• A magnet attracts the metals iron, cobalt and

nickel.• A magnet has two poles called NORTH and

SOUTH.• Opposite poles attract. Like poles repel.



Magnetic Fields• A magnetic field surrounds a magnet.• The lines of force emanate from the north

pole of the magnet and enter the south pole of the magnet.

• A compass needle is an example of a magnet. The north pole of the compass needle points in the general direction of the geographic north pole of the Earth.



Diagram Photograph


Geomagnetism• The Earth itself has a magnetic field.• Because the north pole of the

compass needle points north, the North Magnetic Pole is actually of the south type.

• The North Magnetic Pole is 11½° away from geographic north so there is generally a compass deviation from true north.


Geomagnetism

Map of North Magnetic Pole

The MNP is drifting rapidly,

about 25 miles per year!

from Dr. Eowyn's Blog

http://fellowshipofminds.wordpress.com/2011/01/09/earths-magnetic-north-pole-is-shifting-faster/




Geomagnetism

The origin of the Earth's magnetic field is not completely understood.

It is thought to be associated with electrical currents produced by the coupling of convective effects and rotation in the spinning liquid metallic outer core of iron and nickel.

This mechanism is termed the dynamo effect.


Geomagnetism

The Earth's magnetic field shields it from much of the solar wind.

Auroras are caused by high energy particles from the solar wind that are trapped in the Earth's magnetic field; can be visible or outside visible spectrum

(Photograph of a visible spectrum aurora australis from earthobservatory.nasa.gov)

http://earthobservatory.nasa.gov/IOTD/view.php?id=6226


GeomagnetismAs new crust is formed due to spreading, the rocks become magnetized as they cool.• Magnetized rocks maintain their original magnetic

orientation.• The magnetic field of the Earth reverses occasionally,

causing bands in the magnetic orientation of the sea floor that can be measured with a magnetometer.

• The study of this phenomenon is called paleomagnetism.




Earth’s Atmosphere

and Hydrosphere

18-22 question


The Water Molecule

The Water Molecule is composed of two atoms of hydrogen and one atom of oxygen.


Properties of Water

• High specific heat (1 cal/g)• Polarity--the water molecule behaves as a

dipole (having north and south) when electrified• Density changes--maximum density is at a

temperature of only 4°C. At lower temperatures it expands. That is why ice floats on water. Most other substances shrink when they freeze.

85

The Water Cycle

The water cycle is also called the hydrologic cycle.



Factors Affecting the Weather

Temperature• Generally, air gets cooler as one rises in the

atmosphere. • The temperature depends greatly on the amount

of insolation. (INcoming SOLar radiATION)

• The amount of insolation on the surface of the Earth depends on latitude, altitude, season, and time of day.


Factors Affecting the WeatherFactors Affecting Insolation• The higher the Sun is in the sky, the greater the

insolation.• On a daily basis, insolation is greatest at

noontime.• On a seasonal basis, the Sun is much higher in

the sky in the Summer than it is in the Winter. It is higher in the tropics.

• As the Sun heats the air, it rises. Warm air is less dense so it rises.



The Seasons• The seasons are caused by the inclination of the

Earth’s axis.• Near the poles, there is very little insolation. The

air is very cold.• In the temperate latitudes, it is cold in the Winter

but warm in the Summer.• In the tropics, it is warm all the time.



Time of Day• Daily changes in insolation are called diurnal

variations.• These result in the local daily wind patterns near

the ocean.• During the day, the air over the land is hotter so

it rises. Cool air moves in from the ocean.• During the evening, the air over the water is

warmer. It rises causing the air to move from the land to the water.


Factors Affecting the Weather•Day and night at the shore -- sea breezes.


Factors Affecting the WeatherMoisture• Air contains water vapor which makes the air

humid.• The amount of moisture the air can hold depends

on the temperature.• Absolute humidity is the total moisture that the

air can hold at a given temperature.• Relative humidity is the actual amount of

moisture in the air compared with the maximum amount possible at that temperature.



Air masses• An air mass is a large body of air with uniform

properties of temperature, moisture and pressure.• Continental air masses form over land.• Maritime air masses form over water.• If the air originated in high latitude it is called

Polar. • If it originated in the tropics it is called Tropical.


Factors Affecting the WeatherAir masses commonly found in the USA

•continental Polar (cP)–cold and dry, forms over northern Canada

•continental Arctic (cA)–very cold and dry, from arctic regions

•maritime Polar (mP)–cold and moist, from the North Pacific region

•maritime Tropical (mT)–warm and moist, from Gulf of Mexico


Factors Affecting the WeatherCold Fronts• A front is the boundary between two air masses of different

characteristics.• A continental Polar air mass is cold and dry.• When it moves over the Earth, its edge

is called a cold front which is denoted by a blue line with pointy triangles indicating the direction of movement of the front.



Warm Fronts• A maritime Tropical air mass is warm and moist.

• Its edge is called a warm front and is denoted by a red line with semicircles on it indicating the direction of movement.


Factors Affecting the WeatherStationary front

– When two distinct air masses collide, they produce a stationary front which forms a trough between them.


Factors Affecting the Weather•Absolute humidity is the amount of water vapor in a sample of air.•Relative humidity is the ratio of the amount of water vapor in the air to the maximum amount of water vapor it can hold. (Actual:Possible)

Absolute humidity is related to temperature. The higher the temperature the more moisture the air can hold.When the temperature decreases, the absolute humidity stays the same but the relative humidity increases.


Factors Affecting the WeatherWind• caused by differences in insolation, which

produces global wind belts.• air moves from areas of high pressure to

areas of low pressure.


Factors Affecting the WeatherThe Coriolis forceWhen air moves, the rotation of the Earth makes it pull to the right in the northern hemisphere, to the left in the southern hemisphere.


Clouds• Clouds form when moisture condenses in the

atmosphere.• Clouds are made from tiny droplets of water

or from ice crystals.• Saturated air will form clouds if it is cooled

below the dewpoint (saturation temperature) of the air.

• Clouds are classified by their method of formation and their altitude.


Clouds•Clouds are of basically two types, cumulus and stratus.•Cumulus clouds resemble balls of cotton. They are the typical fair weather clouds. Cumulus means “piled up”.•Stratus clouds are low, gray and in layers. They are associated with stationary fronts and fog. Stratus means “covering”.•Smog is formed from smoke and fog. It results from the accumulation of pollutants in stagnant air.


Clouds

Cloud Altigram © 2011 by Suzanne Rinas Leone, Raleigh NC

aka mares’ tailsThere are three altitude levels:• Low clouds

(cumulo or strato, means “layer”)

• Middle level clouds (alto, means “high”)

• High clouds (cirrus, means “tuft of hair”)

–Cirrus clouds are very high, thin, wispy clouds made of ice crystals.

• Nimbus means “rain”. • Cumulonimbus clouds form

thunderstorms that reach all three levels. They are found along stationary fronts.


PrecipitationPrecipitation occurs when saturated air (usually in the troposphere) continues to be cooled, or when warm, moist air near the surface is carried higher and the humidity condenses.

•Precipitation can take the form of rain, snow, ice, hail, or sleet, as well as dew or frost.


StormsViolent storms get their energy from the heat of fusion of water.

When water vapor condenses high in the atmosphere, it releases 540 calories for each gram (20 drops) of water condensed.

This is a tremendous amount of energy high in the atmosphere where it does not belong. The result is that the energy drives thunderstorms, tornadoes and hurricanes.


Development of a StormWeather map of a typical storm system


Development of a Storm


Development of a Storm


Weather Satellites• provide images and information to the

meteorologist• are used in observation or current conditions,

and short-term prediction of weather.• some are in geosynchronous orbits (the period

of revolution of the satellite around the Earth is the same time as the Earth’s rotation, so the satellite stays over the same part of the Earth all the time)


Weather vs. ClimateWeather • the condition of the atmosphere and its day-to-day

changes• temperature, humidity, winds, precipitation and other

atmospheric conditions

Climate • the average of weather conditions for all the seasons

over a long period of time• temperature, moisture, latitude, nearness to large

bodies of water, and altitude

Climatic zones result from a combination of latitude, proximity to large bodies of water, prevailing winds, insolation and other factors.


Mountains and ClimateThe orographic effect occurs when moist air is carried over a mountain. The windward side of the mountain is very wet while the leeward side is dry.


Mountains and ClimateViews of the climate 50 miles apart

Windward--wet Leeward--dry


Heat BudgetThe heat budget of the earth accounts for the sources and sinks of heat on the Earth.• Sources of heat include: solar radiation,

geothermal inputs and tides. Solar radiation is the most important.

• Heat sinks include reflection of light and radiation of heat from the surface. About 50% of the light striking the Earth is absorbed. Heat energy is radiated by the Earth back out into space. (A heat sink absorbs and dissipates heat.)


El Niño and La NiñaEl Niño is a massive warming of the waters off

the coast of Ecuador and Peru. This warming of the ocean causes flooding, droughts and other weather problems in various parts of the world. It occurs every 3-5 years.

La Niña is a period of unusually cold waters in the tropical eastern Pacific. It occurs only half as frequently as El Niño, and usually lasts for 9-12 months.


Climate Modification• Climate is more moderate near a large body

of water. The summer high temperatures are lower and the winter low temperatures are higher than in the corresponding interior part of a continent.

• Climate can be modified by mountain ranges. This is the orographic effect.

• Climate is modified by altitude. It is colder up in the mountains than it is at sea level.


Human Effects on Climate

Global warming is caused in part by the accumulation of greenhouse gases, mainly carbon dioxide in the atmosphere.

As the greenhouse gases accumulate in the atmosphere, they trap more heat so the global temperature rises. This is called global warming.


Natural Effects on ClimateVolcanoes

•A volcanic eruption spews vast quantities of volcanic ash high up into the atmosphere where it may stay suspended for months or years.•Volcanic ash in the atmosphere screens out solar radiation resulting in a cooling effect on the Earth.Examples:

1980 eruption of Mt. St. Helens in Washington(see the Volcano Cam http://www.fs.fed.us/gpnf/volcanocams/msh/)

Dark Ages caused by the 535 eruption of Mt. Krakatoa in Indonesia

http://www.fs.fed.us/gpnf/volcanocams/msh/

http://www.fs.fed.us/gpnf/volcanocams/msh/


GlaciersA glacier consists of flowing ice formed from compacted snow.


Ocean-Lithosphere Interactions

Estuaries •regions which have fresh water coming in at one and are in contact with the ocean at the other end.•very delicate ecosystems and many contain life forms not found in either fresh water or sea water.•New Jersey has three estuaries. The Lower Hudson River, Raritan Bay and Delaware Bay.


Ocean-Lithosphere InteractionsErosion and deposition

•Erosion is the removal of weathered rock material by water on the surface of the land.•The rock material is deposited in the ocean.•As the particles settle out of the water, the heaviest ones settle out first and are deposited close to the shoreline.•The lightest and smallest particles are carried by the water much further out from the shoreline.



Sea-level changes • recorded over long periods of time.• During the ice ages, the level of the ocean was

much lower than it is today. This caused erosion in parts of the continental shelf that are now submerged.

• An example is the formation of the Hudson Canyon which was cut by the Hudson River during the ice age.



• Waves help to break up coastal rocks and erode the shoreline.

• Tides are periodic high and low levels of the oceans caused by the gravitational attraction of the Moon and the Sun.


The Ocean• The ocean varies in temperature with depth.

It is generally about 4°C at the bottom of the ocean.

• Salinity is a measure of the amount of salt in the ocean. It is generally 35 parts per thousand (35 o/oo)

• There are variations in salinity due to introduction of fresh water and formation of ice.


The Ocean• Deep ocean currents are caused by density.• Cold water is denser (down to 4C) so it

sinks, beginning circulation of deep ocean water.

• Warm water on the surface loses heat to the atmosphere or radiates heat out to space. This cools the water to enable sinking.

• Colder water is generally saltier because when water freezes, the salt remains behind in the liquid water.



By

Frank H. Osborne, Ph. D.

History of the Earth

and its Life Forms

13-17 questions


Uniformitarianism

The assumption that the geological process that we see taking place today have always been at work, and were at work in the past.


Stratigraphic CorrelationOriginal horizontality• based on the observation that when sedimentary particles

settle out of the water, they are under the influence of gravity and form horizontal beds

Superposition• in undisturbed layers of rock, the oldest layer will be found

at the bottom and the youngest layer will be found on the top.

Lateral Continuity• sediment extends laterally in all directions until it thins out

or terminates against the edge of the depositional basin


Stratigraphic Correlation

Example: Grand Canyon•The sedimentary rocks of the Grand Canyon were originally deposited horizontally under the water or in a coastal environment (principle of original horizontality).•The oldest rocks are at the bottom and the youngest are at the top (principle of superposition)•The exposed rocks extend in all directions and can be shown to be in the north and south walls (principle of lateral continuity).


Stratigraphic Correlation

Cross-cutting relationships• used to determine the relative ages of events.• An igneous intrusion or a fault must be younger

that the rocks it intrudes or cuts.

Index fossils• used to indicate rock layers in different places

that are part of the same formation• Rock layers of a given age will generally contain

the same forms of index fossils


Unconformity• a point in the geological record where strata are

missing.• a discontinuity consisting of an erosion surface

between younger strata and older rocks.

Examples:

http://www.cliffsnotes.com/study_guide/topic ArticleId-9605,articleId-9497.html

Angular Unconformity

Disconformity

Nonconformity

http://www.cliffsnotes.com/study_guide/topicArticleId-9605,articleId-9497.html





The Fossil Record

Fossils• A fossil is the remains of something that was

alive or was made by something that was alive.

• The object becomes a fossil as a result of a sequence of steps.


The Fossil Record

Types of fossils• Organic remains may create a depression or mold

which later fills in to become a cast.• Some fossils are made by mineral substitution in

the sediments.• Imprints are impressions made in the sediments

by the object.


The Fossil Record

• Before the discovery of radioactivity, geologists did not know the age of rocks. So they used index fossils.

• Certain kinds of fossils can be used to correlate layers of rocks in different locations.

• Radioactive dating of rocks involves Uranium-238. It has a very long half-life which is 4.5 x 109 (4.5 billion) years.


Paleontology

Paleontology is the study of fossils. • Using fossils, geological time sequences and

fossil positions in the geological record, it is possible to construct a sequence of the development of life on Earth.

• Mass extinctions have occurred at several important points in the fossil record. The most recent is the K-T boundary at 65 million years ago.


How a fossil is formed

• An animal dies and decays. Only the bones remain.



• The bones are covered by sediments under water.



• Over many years the layers of sediments above the bones increase.

• The sediments become sedimentary rock.



• The molecules of the bones are slowly replaced by minerals. Bone turns to stone.



• After some time, uplift causes the rocks to be lifted above sea level.



• Erosion washes the rocks away and exposes the fossil.


Geologic Time Scale•Geologic time is divided into eras, periods and epochs.•Mainly the distinctions are based on fossil evidence.


Age and Dating•Absolute age tells how old something is as compared with the age of the Earth. •In some cases rocks must be compared with each other so only the relative age is known.•Radioactive dating employs measurements of radioactive nuclei that decay at known rates. For example, U-238 decays into Pb-206 at a known rate that can be measured in rocks, thereby providing their ages.


Paleogeography

The continents have not always been in the same locations.

Plate tectonic forces have been at work throughout most of the history of the Earth.

There is evidence that North America used to be located on the Equator and Africa used to be located on the South Pole.

In this case, North America would have been tropical and Africa, frozen.


Paleogeography• Fitting the continents together

– Try cutting the map to fit the Americas and Africa together. We think it looked like this 200 million years ago.



By


Astronomy

8-12 questions


Astronomy• the study of the positions, movements and

structure of celestial objects.• includes: Sun, Moon, planets, satellites,

asteroids, meteors, comets, and stars• includes: the motions of the Earth as it travels

through space


AstronomyThe Earth• the third planet in the solar system (counting from

the Sun)

• approximately 93,000,000 miles from the Sun

• diameter of 7918 miles

• Nearly 3/4 of the surface of Earth is covered by water


AstronomyMotions of the Earth - Revolution• The Earth revolves around the Sun.

• One complete revolution of the Earth around the Sun takes one year.

• Because of this, the patterns of the stars change during the seasons.

• The stars themselves actually move (proper motion) but they are so far away it takes thousands of years to notice any difference in the star patterns.


AstronomyMotions of the Earth - Rotation• The Earth rotates on its axis.

• One complete rotation takes one day.

• The Earth rotates from west to east. This is why the stars rise in the east and set in the west.

• Viewed from above the North Pole, the Earth rotates counterclockwise.


The Seasons

• Like the stars, the Sun appears to move from east to west every day.

• The axis of the Earth is inclined 23½° from the vertical. The vertical is the line perpendicular to the orbital plane of the Earth.

• This inclination causes the Sun to be found at different altitudes in the sky at different times of the year.– Highest point is on June 21—southern solstice

– Lowest point is on December 21—northern solstice


The Seasons

Position of the Earth in different Seasons


The SeasonsSummer• On the “first” day of Summer the Sun is directly

overhead on the Tropic of Cancer.• The Sun is at its maximum altitude in the sky in

the northern hemisphere and it is the longest length of daylight.

• This day is June 21, the Southern Solstice.• During the next three months, the Earth moves

1/4 of the way around its orbit.


The SeasonsAutumn• On the “first” day of Autumn the Sun is directly

overhead on the Equator.• The day and night are of equal length in all parts

of the world.• This day is September 21, the Fall Equinox. • During the next three months, the Earth moves

another 1/4 of the way around its orbit.


The SeasonsWinter• On the “first” day of Winter the Sun is directly

overhead on the Tropic of Capricorn.• It is the shortest length of daylight in the

northern hemisphere and the Sun is at its lowest altitude.

• This day is December 21, the Northern Solstice. • During the next three months, the Earth moves

another 1/4 of the way around its orbit.


The SeasonsSpring• On the “first” day of Spring the Sun is directly

overhead on the Equator.• The day and night are of equal length in all parts

of the world.• This day is March 21, the Spring (Vernal)

Equinox. • During the next three months, the Earth moves

the final 1/4 of the way around its orbit.


The Seasons

Length of Daylight• Varies from day to day • Varies from place to place. • This variation is due to the inclination of the

Earth’s axis and the revolution of the Earth around the Sun.


Time Zones

Time Zones• Time zones were developed to standardize time

around the world.• The International Date Line was positioned in a

relatively unpopulated part of the Pacific Ocean.• A person travelling west across this line has to

advance their calendar by one day.


The Moon• The Moon is the only natural satellite of Earth.• The Moon revolves around the Earth from west to

east. One orbit takes 29½ days.• The Moon has a captured rotation. This means

that it rotates once per orbit. The result is that the same face is always pointing toward the Earth.

• Every month the Moon comes close to the Earth (perigee) and then gets further away from the Earth (apogee).


Phases of the Moon

The Lunar Cycle• As the Moon revolves around the Earth, the angle

of the sunlight hitting the Moon appears to change as observed from the Earth.

• As we view the Moon during every lunar cycle and the angle changes, the Moon appears to pass through its phases.


Phases of the Moon

• The lunar month begins at New Moon when only the shadowed side of the Moon is facing Earth.

• After about 3 days a thin crescent is seen at sunset in the west.

• The lit part of the Moon always points toward the Sun.


Phases of the Moon

• The crescent Moon gets higher in the sky (further east) and thicker every day for2 weeks.

• This is called waxing.

Day 3 Day 5 Day 7


Phases of the Moon

• First Quarter occurs at 1 week when the Moon is one-quarter of the way around its orbit.

• It is in the south at sunset with the lit side pointing west.


Phases of the Moon

• Full Moon occurs when the Moon is on the opposite side of the Earth from the Sun.

• At Full Moon, the Moon rises in the east just as the Sun is setting in the west.


Phases of the Moon

• On the days following Full Moon the Moon rises progressively later and becomes progressively thinner.

• This is called waning.

Day 15 Day 18 Day 22


Phases of the Moon

• Last Quarter is when the Moon is 3/4 of the way around its orbit.

• The Moon is seen in the south at sunrise with the lit side pointing east (toward the Sun as always).


Phases of the Moon

• After Last Quarter the Moon continues waning through progressively thinner crescents.

• Crescent Moon is seen in the east just before sunrise.

• After that, New Moon begins another cycle.


Eclipses

Eclipses are products of the Earth-Moon-Sun system.• The orbit of the Moon is tipped at an angle of 5°

to the plane of the Earth’s orbit. • For this reason, eclipses do not occur every

month.• Eclipses cannot be seen from all points on Earth

at the same time.


Eclipses

Eclipse of the Sun (Solar eclipse)• Eclipse of the Sun occurs at New Moon time.• The Moon passes in front of the Sun and blocks it

out.


Eclipses

Eclipse of the Moon (Lunar eclipse)• Eclipse of the Moon occurs at Full Moon time.• The Moon passes through Earth’s shadow and

darkens temporarily.


Astronomical Basis for Tides

• Water on Earth is closer to the Moon than the center of the Earth is. (Radius of Earth is 6378 kilometers.)

• Moon’s gravity attracts water closest to it so the water accelerates toward the Moon.



• Likewise, the center of the Earth is closer to the Moon than the water on the opposite side so the Earth accelerates toward the Moon a little.

• The result of the attractions by the Moon is the production of two tidal bulges one on each side of the Earth.



• As the Moon revolves around the Earth the tidal bulges follow it.


Planets• Planets are celestial bodies that revolve

around the Sun. They are major components of the Solar System.


PlanetsHow the planets differ• Mercury, Venus, Earth and Mars are small

and rocky. These are known as the terrestrial planets because they resemble Earth.

• Jupiter, Saturn, Uranus and Neptune are large and gaseous. They are known as the Jovian planets because they resemble Jupiter. They are also called the gas giants.


PlanetsDwarf Planet Criteria

Ceres, Pluto, Haumea, Makemake, and Eris (plus 50-200 more still to be classified!)• Orbits the Sun (possibly after the formation of the

solar system)

• Has sufficient mass to assume a nearly round shape

• Is not a satellite of a planet

• Has not “cleared the neighborhood” around its orbit (become gravitationally dominant)

http://www.iau.org/static/resolutions/Resolution_GA26-5-6.pdf

http://www.iau.org/static/resolutions/Resolution_GA26-5-6.pdf


PlanetsPlanets change their position in the sky as seen from

Earth against the background of stars because the planets are much closer to Earth than the background stars are.

The planets orbit the Sun at different rates, therefore their positions in the sky constantly change.

As Earth passes by a slower planet (one whose orbit is further out) the planet seems to be moving backward for a time. This is called retrograde motion.


Sizes of the PlanetsAssume Earth has a mass of 1.00. The relative

masses of the planets are as follows:

Mercury (0.06) Saturn (95.16)

Venus (0.82) Uranus (14.50)

Mars (0.11) Neptune (17.20)

Jupiter (317.83)

In comparison, the mass of the Moon is 0.012, the mass of Pluto is 0.0025, and the mass of the Sun is 332, 946.0


Orbits in the Solar SystemOther elements of the solar system• Asteroids are smaller bodies that orbit the Sun

in the Asteroid Belt. The Asteroid Belt is located between the orbits of Mars and Jupiter.

• A comet is a solar system object whose orbit forms an arc near the Sun. Comets are recurrent, meaning that they return periodically. They are made of frozen gases and solid particles making them like “dirty snowballs.”


Orbits in the Solar SystemOther elements of the solar system• Meteoroids are small particles which orbit the

Sun. When they enter the atmosphere they burn up forming meteors, which are the streaks of light. If a solid object makes it all the way to the ground it is a meteorite.

• Planetary orbits in the Sol system (ours) orbit Sol, are generally elliptical, and are in the same plane.


Orbits in the Solar SystemKepler’s Laws of Planetary Motion• The orbit of a planet is an ellipse

with the Sun at one of the two foci.• As a planet revolves around the Sun it sweeps

out arcs of equal areas in equal times.• The square of the sidereal period (the time it takes an

object to make one full orbit, relative to the stars) of a planet is proportional to the cube of the semi-major axis of its orbit (an ellipse's long radius). SP2 :: SMA3


The Stellar SystemStars twinkle because they are so far away that

the light appears as a point.

Planets have a measurable diameter in the sky because they are closer so they don’t twinkle.

Stars are organized into groups called constellations. Different constellations are seen during different seasons because the Earth revolves around the Sun. Over the year, therefore, there are changes.


The Stellar SystemTemperature and color• Stars are categorized according to color

(temperature).• As the colors proceed across the spectrum from

red toward blue, the temperatures of stars increase.

• Color of a star and surface temperature of stars are related.

• Dark line spectra result from absorption of light by cooler gases at the surface of the star.


The Stellar SystemBrightness• The brightness of a star is its magnitude.• The brightness as seen from Earth is called the

apparent or visual magnitude.• Some stars are further away but give off more

light. Therefore, we can speak of the real amount of light given off which is the absolute magnitude.


The Stellar SystemLife Cycle of Stars• Stars form by condensation of vast quantities of

gas and dust.• When they achieve sufficient mass, they ignite

nuclear reactions which give off light, heat and other radiation.

• When they run out of hydrogen, they begin to fuse other elements until they are used up. They then become red giants.


The Stellar SystemLife Cycle of Stars, continued

Red giants eventually collapse and become white dwarf start which are about the size of the Earth.

Some really massive stars explode violently to cause a supernova. The nuclear reactions involved in the explosion create all of the elements in the periodic table.



Sometimes the collapse of a star causes all of the mass to become concentrated in one small object (about 5 - 15 km in radius, but with tremendous mass) . This produces a neutron star.

Larger such masses produce black holes. The gravity in a black hole is so great that not even light can escape.



Sometimes the collapse of a star causes all of the mass to become concentrated in one small object (about 5 - 15 km in radius but with tremendous mass) . This produces a neutron star.

Larger such masses produce black holes. The gravity in a black hole is so great that not even light can escape.


The Stellar SystemHertzprung-Russell Diagram

A Hertzprung-Russell diagram plots absolute magnitude against color (temperature).

Most stars fall along a line which is known as the main sequence, meaning they are fusing hydrogen into helium. Various

stars in different stages of development fall on this line, so the line gives an indication of the life cycle of stars.

Open_cluster_HR_diagram_ages.gif

http://upload.wikimedia.org/wikipedia/commons/2/27/Open_cluster_HR_diagram_ages.gif


The Stellar SystemComposition of stars

Stars are made of vast quantities of gas, usually hydrogen, that fuses into helium producing energy.

Different elements in stars give off different spectra which can be duplicated in the laboratory. The spectrum of a star can be analyzed to determine the composition of the star.


The Stellar SystemDistances in the Universe

Light travels at a speed of 300,000 km/sec or 186,000 miles/sec.

At this rate, light will travel 5.87 x 1012 miles in one year. This distance is known as a lightyear.

The parsec is the distance away of a star that would have a parallax angle of one second. A parsec is about 3.09 x 1016 meters, or 3.262 lightyears.


The Stellar SystemParallax is the apparent shift in locations of an

object when it is viewed from two different positions.

Nearby stars display parallax when compared to distant stars which allows their distances from Earth to be calculated by triangulation.


The Stellar SystemCepheid variables are luminous giant stars whose

luminosity varies in a periodic fashion (a rapid rise in luminosity that is followed by a slow decline).

The more luminous ones have longer periods.

The periodicity and luminosity relationship allows distances to be calculated in the universe.


GalaxiesA galaxy is a vast number of stars rotating about a

black hole which forms the center of the galaxy.

There are also galaxy clusters which contain groups of galaxies that are gravitationally bound to each other.

The Sol system is located in the Milky Way Galaxy.

All stars that can be seen individually from Earth are part of the Milky Way galaxy.


Telescopes

Telescopes are used to view distant objects.

Refractors are telescopes with lenses that bend the light and create a magnified image of the object. These lenses are looked through directly.

Reflectors collect light using a mirror. The light is then passed through a lens for viewing.


Telescopes

Hubble Space Telescope

Telescopes on the ground all have to view objects in space through the Earth’s atmosphere which causes distortion and absorption problems.

The Hubble Space telescope is in orbit above the atmosphere and therefore can “see” better than any telescope on Earth.


Satellites and InstrumentsHumans can extend their senses by attaching

detectors to satellites.

Space probes are used to detect electromagnetic radiation, dust and other things of interest to scientists.

Recent landings on Mars have extended the senses of the geologist who can probe Martian rocks and other objects via satellite.


Satellites and Instruments

The International Space Station may someday be a staging area for human exploration of the solar system.

Humans have already landed on the Moon.

The Space Station can also permit scientists to perform experiments in space under zero-gravity conditions.


Satellites and Instruments

Computers are used for data analysis and storage of information obtained from satellites.

Some satellites have been sending back prodigious amounts of information that will be keeping scientists busy for years. One such was the Infrared Telescope that was sent up in and operated in the 1990s.


The Universe

The Universe is thought to have begun with a “big bang” over 15 billion years ago.

Evidence for this is that the furthest objects in the Universe are moving away at the fastest rates.

Because these objects are so far away, the light that we see today left them billions and billions of years ago.


Other Objects of the UniverseA quasar is a quasi-stellar object. These give out radio

waves. Quasars are moving away among the fastest objects in the Universe.

A pulsar is produced when a star explodes. The explosion produces heavy elements and changes much of the mass of the star to energy. The explosion is called a supernova.

After the supernova, the remains of the star forms a neutron star. These are very dense and rotate very rapidly--so rapidly that they pulsate.

A black hole results from a supernova with a large enough remnant that no light escapes from its gravitational pull.



By


Basic Principles of Earth and Space Sciences

8-12 questions


Earth Science in NC

“The Earth/Environmental science curriculum focuses on the function of Earth's systems. Emphasis is placed on matter, energy, plate tectonics, origin and evolution of the earth and solar system, environmental awareness, materials availability, and the cycles that circulate energy and material through the earth system.” (NC SCOS, 2004)


Humans & Energy

Humans use various sources for production and use of energy. • These include fossil fuels (coal, oil, natural gas),

nuclear, geothermal, hydroelectric, and solar.• Most are non-renewable. Anything dug out of

the ground will eventually run out.

Teachers should be aware of the issues surrounding these sources of energy, and the points of discussion over each.


Energy & the Electromagnetic Spectrum

Electromagnetic energy is found in waves.• The energy is indicated by the wavelength.

The shortest waves have the most energy while the longest waves have the least energy.

• The electromagnetic spectrum is logarithmic. This means that each unit is a factor of 10 (10 times larger or smaller than the unit next to it).



Energy in Earth Systems

Earth has external and internal sources of energy in the form of heat.• external = the Sun.• internal =

Radioactive decay

Gravitational energy resulting from the Earth’s mass


Energy in Earth SystemsHeat escapes slowly from Earth’s core.• The transfer of heat from within the Earth produces

convection currents in the mantle.• The convection currents of the mantle cause movement

of the tectonic plates of the crust as the mantle carries them along with it.


Energy in Earth Systems

Insolation means Incoming Solar Radiation

Heating by the Sun causes convection currents in the atmosphere and the oceans.• Convection in the atmosphere causes the

global wind patterns and belts.• Convection in the ocean results in the global

pattern of ocean currents.


Energy in Earth SystemsWind is caused by uneven insolation.• The differential heating

of the atmosphere produces global wind belts.

• In our latitudes, the predominant wind direction is from the west. At the poles and also in the tropics, the winds blow from the east.

• Air moves from areas of high pressure to areas of low pressure, seeking to create equilibrium.


Energy in Earth SystemsConvection currents in the oceans result in ocean currents.• Deep ocean currents are driven by gravity.

The densest water sinks causing convection currents in the ocean.

• As warm water currents release their heat to the atmosphere, they sink.


Insolation and ClimateThe higher the Sun is in the sky, the greater the insolation.• On a daily basis, insolation is greatest at

noontime.• On a seasonal basis, the Sun is much higher

in the sky in the Summer than it is in the Winter. It is higher in the tropics.

• As the Sun heats the air, it rises. Warm air is less dense so it rises.


Insolation and ClimateThe Seasons• The seasons are caused by the inclination of

the Earth’s axis.• Near the poles, there is very little insolation.

The air is very cold.• In the temperate latitudes, it is cold in the

Winter but warm in the Summer.• In the tropics, it is warm all the time.


Laws of Thermodynamics

Thermodynamics describes how systems change when they interact with one another or with their surroundings.

Zeroth Law: If two systems are each in thermal equilibrium with a third, they are also in thermal equilibrium with each other.


Laws of Thermodynamics

First Law: The amount of energy in a system stays the same. (obeys Conservation of energy).

Second Law: Heat never flows from a cold substance to a hot substance, only toward complete entropy (disconnection within a system).

Third Law: No system can reach absolute zero, or complete entropy.


Heat vs. Temperature

Heat and temperature• Heat is a form of electromagnetic energy. • Temperature is the average kinetic energy of

the particles in the substance. If the substance gets hotter (more energy), the kinetic energy of the particles increases and the temperature rises.


Transfer of Heat

Heat can be transferred in three ways.•Conduction is transfer of heat by direct contact.•Convection is transfer of heat via currents of water or air.•Radiation is transfer of heat via electromagnetic radiation.

Heat is always transferred from hotter to colder.


Transfer of Heat


Greenhouse EffectClear glass (or gas) can act as a mirror for certain wavelengths and transmit others.• In a greenhouse, light passes through the glass.

Once inside, it is absorbed and re-emitted as heat. The greenhouse heats up because heat will not pass through glass.

• “Greenhouse gases” such as CO2 are suspected of causing the same effect in the atmosphere resulting in global warming.


Atomic Structure

Structure of the Atom•The nucleus is made of protons and neutrons.•The electrons travel in orbits (valence shells) around the nucleus.•Atomic number = number of protons.•Atomic mass = number of protons + neutrons. (Find the number of neutrons by subtraction.)


•Matter is made of elements. •Matter exists as a solid, liquid or gas.•Matter can change phase (or state) by absorbing or releasing heat.•Melting is the change from solid to liquid. For water, the heat of fusion is 80 cal/g.•Boiling is the change from liquid to gas. For water the heat of vaporization is 540 cal/g.

Structure & Properties of Matter


Structure & Properties of Matter•Matter has various physical and chemical properties. These include:

–melting point, boiling point, color, density–combustibility, oxidation potential, reactivity

•Matter is organized in the form of elements and compounds.•Different compounds can form mixtures and solutions, or they can react to form different substances.


•An element is a substance that cannot be decomposed by ordinary means.•Each element has its own atomic structure.•There are over 100 elements. • The Periodic Table of the Elements which arranges

the elements by properties.• In the Earth’s crust:-

–Oxygen is 93.8% by volume–Oxygen and Silicon are 74.3% by mass–The remaining abundant elements by mass are Al, Fe,

Ca, Na, K and Mg. The rest are only 1.5%.



Periodic Table of the Elements



Nuclear Reactions

Radioactivity is a property of atoms that have an unstable nucleus.

There are three major types of radiation produced.• Alpha (a) radiation--the nucleus emits a nucleus

of helium.• Beta (b) radiation--the nucleus emits an electron.• Gamma (g) radiation--the nucleus emits very

powerful electromagnetic radiation.


IsotopesIsotopes are atoms with the same atomic number (protons) but different atomic masses (neutrons).


Half-life

Half-life is the length of time necessary for half of a given quantity of radioactive nuclei to decay.


Nuclear Fission

Nuclear fission occurs when a large, unstable nucleus is broken apart. Some of the binding energy is released.

–1. A slow neutron is captured by U-235 which becomes U-236 which is unstable.–2. The U-235 nucleus splits releasing two smaller nuclei and some neutrons. Sometimes one of these is I-131.–3. The neutrons can become captured by other nuclei of U-235 causing a chain reaction.


Nuclear Fission


Nuclear Reactors

A nuclear reactor contains a controlled nuclear fission chain reaction.• The controlled reaction occurs at a constant rate.• The heat released from the reaction is used to

boil water to make steam.• The steam is used to produce electricity by

driving turbines.


Nuclear Reactors


Nuclear Fusion

Nuclear fusion occurs when small nuclei are forced together.• Nuclear fusion occurs in the Sun and is

known as thermonuclear energy. It is the same as is released in the hydrogen bomb, which is uncontrolled.

• On Earth, the fusion reaction has not been controlled.


Nuclear Fusion


Nuclear Fusion

Mass can be converted to energy in nuclear reactions.•The relationship between mass and energy was derived in Einstein’s theory of relativity.

•In this equation, E is the energy, m is the mass and c is the speed of light.


Fundamental Processes

• Evolution• Repetitive Cycles• Biogeochemical Nutrient Cycles• Chemical reactions • Gravity



Evolution• the theory used to explain the origin of

different species of living creatures.• involves accumulation of biological changes

over time.• Fossils provide evidence of creatures that

lived in the past but are extinct today.



Biogeochemical cycles

The environment contains numerous cycles which are used to circulate nutrients in the ecosystem.



Cyclic change• Natural cycles repeat themselves

Motion of celestial objects

Changes in the seasons

The Rock Cycle

The Water Cycle

• Many changes can be measured so they can be predicted, ex: solar and lunar eclipses.



Chemical reactions• Many different substances can react with

each other to produce new substances.• Chemical reactions are one of the causes of

weathering of rocks and contribute to erosion.• Acid precipitation in the form of rain, snow

and other forms accelerates erosion of certain rocks, such as limestone.



Gravity• Gravity is the attraction of objects by the

Earth’s mass.• Gravitational energy is one source of the heat

inside the Earth.• Gravity is involved in erosion and also must

always be considered in the space sciences.


WavesTypes of waves•Transverse waves cause the particles of the medium to vibrate at right angles (perpendicular) to the direction in which the wave is moving. Example: a wave made by shaking a rope.•Longitudinal (compression) waves cause the particles of the medium to vibrate parallel to the direction in which the wave is moving. Example: squeezing a section of a slinky toy.


Waves•Transverse waves

•Longitudinal (compression) waves


WavesWater wavesWater waves are of the transverse type. The wind provides the energy for water waves. Size of the wave is determined by:•Speed of the wind•How long it blows•How far the wind travels


WavesEarthquake (seismic) wavesThere are two types of earthquake waves:



By


History & Nature of Science

0-5 questions


The Scientific Method

The Scientific Method has several steps:•A natural phenomenon is observed•A hypothesis (proposed explanation) is made•An experiment is performed•Results are obtained•The hypothesis is supported or disproved•Any scientific explanation is called a theory


The Nature of Science•Science is based on observations and measurements, not on belief or dogma.•We learn in science, not by proving something true, but by proving something else to be false.•All scientific knowledge is tentative.•There is not just one method.


The Nature of Science•Scientific knowledge is consistent with evidence, subject to change and open to criticism.•Models are used to help study natural things and processes.•Science has many disciplines but the knowledge forms a unified whole.


The History of Science

Some major figures in science:•Curie•Mendel-genetics•Darwin-evolution•Galileo-heliocentric astronomy•Hutton•Mendeleev•Einstein-physics•Dalton


The History of Science

Some major events in science:•DNA structure•Big bang theory•Atomic imaging•Light bending in gravitational fields


The Metric System

The Metric System is used for measurement.•Length is measured in units of the meter.•Volume is measured in units of the liter.•Mass is measured in units of kilograms.•Time is measured in units of seconds.


The Metric System

Prefixes used in the Metric System


Processes of Science•Scientific data collection•Analysis and interpretation using charts and graphs•Data manipulation•Presentation•Critical analysis of sources of data•Analysis of errors using statistics and error procedures


Laboratory Safety and Procedures•Scientists need to know and understand the rules, regulations, policies and procedures involving laboratory and field materials.•This includes the preparation, use, handling, storage and disposal of chemicals and biological materials.•Scientists should be able to identify, use and maintain science equipment and apparatus properly in the lab and field.


Laboratory Safety and Procedures•Special precautions are necessary for handling, use, storage and disposal of acids, bases, toxic materials, microbiological samples, as well as materials that are health and fire hazards.•Scientists should be able to prepare reagents, materials, and equipment setups properly for laboratory and classroom use. They should also understand and follow humane treatment procedures for living organisms.


Laboratory Safety and Procedures•Teachers should know and understand the legal responsibilities associated with safety and emergency procedures for the science classroom and laboratory.•This includes understanding and compliance with all rules, regulations, policies and procedures regarding classroom and laboratory safety.


Equipment •Teachers should know and understand the appropriate use of equipment and instruments for making measurements and observations in the Earth Sciences.•This includes use of computers and related technologies as they apply to scientific investigation.

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Praxis Review for Earth Science By Frank H. Osborne, Ph. D. Kean University Union, New Jersey...

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