spring 2006, pflugerville isd © spring 2006, pflugerville isd, 6th grade 6th grade science

Spring 2006, Pflugerville ISD© Spring 2006, Pflugerville ISD, 6th Grade

6th Grade Science

Spring 2006, Pflugerville ISD

Unit 6Earth Systems and Structure

Chapter 17: The Restless EarthSection 1: Inside the EarthSection 2: Continents on the Move – Review only.Section 3: Tectonic ForcesSection 4: Building MountainsChapter 18: The Flow of Fresh WaterSection 1: The Active RiverSection 2: Stream and River DepositsSection 3: Water UndergroundChapter 19: The Earth’s AtmosphereSection 1: Characteristics of the AtmosphereSection 3: Atmospheric Pressure and Winds

Chapter 17 Section 1 Spring 2006, Pflugerville ISD

Inside the Earth


How do we know what the inside of the Earth looks like?

What Do You Think?

Inside the Earth


Inside the Earth

The outer layer of the Earth in less dense than the inner layer.Three main layers of the Earth: crust, mantle, core. Cite: http://www.kidscosmos.org/kid-stuff/mars-trip-graphics/earth-interior-diagram.gif


The crust ranges from 5-100 km .Continental crust is made of light and less dense materials: silicon, oxygen and aluminum.

Oceanic crust is made of heavy and more dense materials: iron, calcium, and magnesium.

Inside the Earth

Cite: http://binky.thinkquest.nl/~ll125/images/struct.jpg


The mantle is between the crust and the core. It is very thick and has the most mass.

We infer what the mantle looks like by looking at the surface of the Earth. The mantle is made of iron and magnesium.

Inside the Earth

Cite: http://www.greatbasinnaturalhistory.org/Geology/Images/Mantle%20Convection.gif


The core begins at the bottom of the mantle and ends at the center.The core is made of iron, nickel , sulfur and oxygen.

Inside the Earth

Cite: http://www.oup.co.uk/images/oxed/children/yoes/earth/earthcore.jpg


When we study the Earth we look at the physical properties of its layers:

Temperature, density and ability to flow( viscosity)

Inside the Earth


– Lithosphere

– Asthenosphere

– Mesosphere

– Outer core

– Inner core

Inside the Earth

Cite: http://jersey.uoregon.edu/~mstrick/AskGeoMan/AskGeoImages/Earth.layers.image.gif


The lithosphere is the crust and the rigid upper part of the mantle.It is divided into pieces called plates.

Inside the Earth

Cite:http://www.craigtutoring.com/earthscienceimages/lithosphere.gif


Inside the Earth

The asthenosphere is the soft layer on which the plates move.

It is solid rock, flow very slowly.

Cite: http://www.ucmp.berkeley.edu/geology/curr2.JPG


Inside the Earth

The mesosphere is the strong lower part of the mantle.

Cite: http://courses.eas.ualberta.ca/eas421/images/diagrams/0108earth.gif


Inside the Earth

The outer core is the liquid layer that slowly circulates.

Electrical currents within it generate the Earth’s magnetic field.

Every 100,000years or so, the magnetic field reverses itself.

Cite: http://news-service.stanford.edu/news/2002/april24/gifs/earth_350.jpg


Inside the Earth

The inner core is a solid, dense center.

Temperature is around 4300 degrees Celsius.

Scientist know this by recreating pressures like that of the core.

Cite: http://www.phschool.com/atschool/science_activity_library/images/earths_interior.jpg


Earthquakes give us the answers about the earth interior through seismic waves or vibrations. They travel through the Earth at different speeds. For examples- Seismic wave through rock travels faster than through liquid.Seismographs measure the times at which different waves arrive, and record the speed.

Inside the Earth


Inside the Earth

Cite: http://www.thetech.org/exhibits_events/online/quakes/seismo/images/seismograph.gif

Seismograph in action


Click here to view the interior of the earth.

Inside the Earth

http://scign.jpl.nasa.gov/learn/plate1.htm


Build a model of the Earth using peanut butter, jelly, chocolate chips, dried milk and honey. Relate each substance to each layer of the Earth.

Inside the Earth

Activity

See speaker notes for lab.


Take a journey to the center of the Earth by creating a scale model of the Earth. Along the way, explore each layer and examine the characteristics of each layer.

Pre-AP Extension



1. Explain why seismic waves travel more rapidly through the mesosphere than through the

outer core.

Let’s Review


Seismic waves travel more rapidly through the mesosphere because

the mesosphere is solid and densely packed, while the outer

core is liquid.

Answer


2. What is the difference between continental and oceanic crust?

Let’s Review


Oceanic crust is thinner and denser than continental crust.

Continental crust is mostly silicon, oxygen, and aluminum. Oceanic crust is rich in magnesium, iron

and calcium.

Answer


3. How is the lithosphere different from the asthenosphere?

Let’s Review


The lithosphere is rigid and is divided into tectonic plates. The

asthenosphere is a layer of mantle material that flows very

slowly.

Answer


Tectonic Forces


What causes mountains to form?

What Do You Think?

Tectonic Forces


Stress is the amount of force per unit area put on a given object.

Deformation is the rock changing due to stress.

Three things determine how much stress a rock can handle: composition, temperature and amount of pressure.

Tectonic Forces


Tectonic Forces

Compression is when two plates collide. (squeezing)

Tension is when two plates pulling away from each other. (stretching)

Cite: http://www.solaster-mb.org/mb/images/dyrynda-tectonics-1-wl.GIF


Folding is the bending of rock

Anticline are arch-shaped folds.

Syncline are trough-shaped folds.

Monocline are rocks that have vertical stress and the ends are still horizontal.

Anticline

Tectonic Forces

Cite:http://www.salem.k12.va.us/staff/flester/lester/foldsandfaults/anticline.gif

Syncline

Cite: http://www.salem.k12.va.us/staff/flester/lester/syncline.gif


Monocline

Tectonic Forces

Cite: http://www.nps.gov/brca/Geodetect/Photo%20book/LF%20pix/images/Monocline%20Cross%20Section%20_TIF.jpg


Tectonic Forces

Cite: http://www.geosci.unc.edu/faculty/glazner/Images/Structure/Monocline.jpg

Monocline in the Mojave Desert, California


• Cite: http://www-class.unl.edu/geol101i/images/structure%20images/anticline%20from%20Wind%20Rivers.jpg

Anticline in Wind Rivers, Wyoming

Tectonic Forces


Tectonic Forces

Cite: http://users.ipfw.edu/isiorho/Syncline.JPG


Faulting is breaking of rocks

Footwall is one side of the rock.

Hanging wall is the other side of the rock.

A normal fault is when the rocks pull away from each other, the hanging wall moves down.

A reverse fault is when rocks are pushed together, the hanging wall is pushed up.

Tectonic Forces


Normal Fault

Tectonic Forces

Cite: http://www.calstatela.edu/faculty/acolvil/struct/normal_animation.gif


Reverse Fault

Tectonic Forces

Cite: http://www.earthsci.org/struct/fault/reverse.gif


Strike-slip Fault is when the rock breaks and move horizontally.

Tectonic Forces


Tectonic Forces

Strike Slip Fault

Cite: http://darkwing.uoregon.edu/~nfay/home/right_lateral_fault.gif


Using play dough, model the layers of the Earth and see what happens when the plates move.

Tectonic Forces

Activity



1. Name tow types of stress, and describe how they affect the

Earth’s surface.

Let’s Review


Compression squeezes the crust together and forms folds and

reverse faults. Tension pulls the crust apart and forms mid-ocean

ridges and normal faults.

Answer


2. What is the difference between a normal fault and a reverse fault?

Let’s Review


A normal fault forms as a result of tensional stress and the hanging wall moves down relative to the footwall. A reverse fault forms as a result of

compressional stress, and the hanging wall moves up relative to the

footwall.

Answer


Building Mountains


Why are the Appalachian Mountains in the middle of the North American

plate?

What Do You Think?

Building Mountains


Most mountain ranges form where plates collide- convergent boundary.

Uplift is the process by which regions of the crust are raised to a higher elevation.

Building Mountains


Building Mountains

Cite: http://www.calstatela.edu/faculty/acolvil/plates/subduction.jpg


Folded Mountains are formed when rock layers are squeezed together. Appalachians

Fault - Block Mountains are formed when faulting causes large blocks of the crust to drop down. Tetons

Volcanic Mountains are formed when molten rocks erupts onto the Earth’s surface. Divergent boundary.

Building Mountains


Building Mountains

Fault Block Mountains

Citehttp://cse.cosm.sc.edu/erth_sci/Metamorf/ue3588.jpg:


Cite: http://cse.cosm.sc.edu/erth_sci/Metamorf/ue1868.jpg

Building Mountains

Folded Mountains in Canada


Volcanic Mountain

Building Mountains

Cithttp://cse.cosm.sc.edu/erth_sci/Metamorf/ss5_3.jpge:


You are going to research a mountain and find a photograph of the mountain. We will place all the different mountains around the room and you will tour the museum.

Building Mountains

Activity



It can takes millions of years for a mountain to form or sometimes just a few years. Research a mountain and create a timeline on the formation of the mountain.

Pre-AP Extension



1. Name and describe the type of tectonic stress that forms folded

mountains.

Let’s Review


Folded mountains form when compression pushes layers of

rock into huge folds.

Answer


2. Name and describe the type of tectonic stress that forms fault-

block mountains.

Let’s Review


Fault-block mountains form when tension pulls rock apart and

causes a large number of normal faults to form.

Answer


3. Explain how volcanic mountains change the surface of the Earth.

Let’s Review


Volcanic mountains change the surface of the Earth by adding

material to it.

Answer


The Active River


What are the parts to the water cycle?

What Do You Think?

The Active River


The Active River

Erosion is the removal and transport of rock and soil by the flow of water and by the action of wind , ice and gravity.

Cite:http://www.fotos-und-grafik.de/fichtel/natur/erosion/erosion.jpg


The water cycle is a continuous movement of water.Parts of the water cycle are:1. Condensation is when water vapors cool and change into liquid water droplets that form clouds.2. Precipitation is rain, snow, sleet or hail that falls from the clouds to the Earth’s surface.

The Active River


3. Evaporation takes place when liquid water from the Earth’s surface changes into water vapor. Energy from the sun causes evaporation.

4. Water vapor is also added to the air by plants (transpiration).

Water gains energy during evaporation- endothermic.

Water loses energy during condensation- exothermic.

The Active River


Cite: http://www.tkp.edu.hk/~lscn/6a/hydrologic_cycle.gif

Hydrological Cycle

The Active River


Runoff is water that flows across the land and enters rivers and streams. It eventually flows into lakes and oceans.Percolation is the downward movement of water through soil and rock due to gravity.Tributaries are smaller streams or rivers that flow into larger ones.

The Active River


A watershed is the region of land drained by a river system. Mississippi Watershed is the largest in U.S.

Divides separated the watersheds.

A channel is the path that a stream follows.

Gradient is the measure of the change in elevation over a certain distance.

The Active River


The Active River

Click here to watch a short video on watersheds.

http://www.wpconline.org/SHC/movies/watershed_graphic.mov


The Active River

Discharge is the amount of water that a stream or river carries in a given amount of time.

Load is the materials carried by a river or stream.

Cite: http://www.ecy.wa.gov/programs/wq/images/yak_wq_images/dirty_ri.jpg


Young- erodes channels deep, river flows quickly and is straight.Mature- erodes wider, meanders, gradient not as steep as young river and has more tributaries and discharge.Old- has little gradient and little erosion. Oxbow lakes and large amount of meanders.Rejuvenated- land is raised due to plate tectonics and river becomes steeper.

The Active River


Get some pictures of different rivers and see if the students can figure out the age of the rivers based on the characteristics of each river.

The Active River

Activity


The Active River

Explore a river system by clicking here.

http://www.nationalgeographic.com/geographyaction/rivers/


You will make a model of the water cycle, and you will watch water as it moves through the model.

The Active River

Activity



1. Explain the interactions between matter and energy in the water

cycle.

Let’s Review


Liquid water gains energy form the sun and evaporates. As water

evaporates, it changes into water vapor. Water vapor rises and

condenses to form clouds. As the water vapor condenses, it loses

energy, and water falls back to the Earth as precipitation.

Answer


2. Describe the differences between a river system and a

watershed.

Let’s Review


A river system is a network of streams and rivers. A watershed is the region of land drained by a river system. River systems are

mad up of smaller systems of streams and tributaries.

Answer


3. Describe the ways that youthful, mature, old, and rejuvenated

rivers shape the Earth’s surface.

Let’s Review


Youthful rivers erode deep channels. Mature rivers erode wide channels. Old rivers deposit sediment in their channels and along their banks.

Rejuvenated rivers form terraces in the river valley.

Answer


Stream and River Deposits


Why are some farms located near a river?

What Do You Think?



Rivers erode and carry enormous amounts of sediment.

When the river’s current slows down the sediment is deposited.

Deposition is the process by which material is dropped.




Cite:http://www.rcgroups.com/gallery/data/512/10591CO_River_1-19-03__4_.jpg

Deposition happens along the insideof the bank , where the current is slower.

Erosion happens on the outsidebank, where the current is faster.


A delta is formed where a river’s current slows down and sediment is deposited in a fan- shaped pattern. New land is built.An alluvial fan is created when fast moving water flows onto a flat plain and sediment is deposited in a fan-shaped pattern. A flood plain is when a river overflows its banks.




Delta

Alluvial Fan

Flood Plains

Cite: http://www.windows.ucar.edu/earth/geology/images/alluvial_fan_lg.jpeg

Cite: http://www.lizander.com/workforsale/images/patterns_river_delta.jpg

Cite: http://www.wildlife-art.co.uk/new_site/graphics/earth_science/flood_plain.jpg


1. Describe how river deposition forms deltas, alluvial fans, and

flood plains.

Let’s Review


Answer

A delta is formed where a river’s current slows down and sediment is deposited in a fan- shaped pattern. New land is built.An alluvial fan is created when fast moving water flows onto a flat plain and sediment is deposited in a fan-shaped pattern. A flood plain is when a river overflows its banks.


Water Underground


Where does the water go after it rains?

What Do You Think?

Water Underground


Ground water is water that is beneath the Earth’s surface.

97% of the world’s liquid fresh water is stored here.

There are two zones underground:

1. Zone of aeration

2. Zone of saturation.

Water Underground


Zone of Aeration is the upper zone where rain water passes.

Zone of Saturation is where water collects.

Where these two zones meet is at the water table.

Water table rises during wet years and lowers during dry years.

Water Underground


Water Underground

Citehttp://www.geo.sunysb.edu/classes/oldclasses/cei542/notes/watertable.jpg:


An aquifer is a rock layer that stores ground water and allows it to flow.

Porosity is the amount of space between the particles that make up a rock.

Aquifers allow water to pass freely from one pore to another.

Permeability is a rock’s ability to allow water to pass through it.

Water Underground


Water Underground

Cite: http://www.dac.neu.edu/Earth/m.wizevich/GEO200/Week11/Porosity1.gif


Cite:http://www.rw.ttu.edu/2302_butler/images/permeability.jpg

Water Underground


Which substance has more permeability sand or soil? Find out how long it takes for water to travel through each of these substances.

Water Underground

Activity



Best aquifers usually form in permeable materials such as sandstone, limestone, and layers of sand and gravel.

Recharge zone is the ground surface where water enters an aquifer. (marked by signs).

The size of the recharge zone depends on the layer of rock.

Water Underground


Water Underground

Cite: http://pasture.ecn.purdue.edu/~epados/ground/images/recharge.gif


Ground water movement depends on the slope of the water table.

If the water table reaches the Earth’s surface, water will flow out from the ground and form a spring.

A well is a human-made hole that is deeper than the level of the water table. Water is filtered and purified as it travels through an aquifer.

Water Underground


Water Underground

Cite: http://www.artesianwater.com/kids/Aquifer.jpg


Most caves are formed as ground water dissolves the limestone.

Stalactites are sharp- icicle shaped features that are from deposits of calcium carbonate.( Hang from the ceiling)

Stalagmites form when water falls to the cave floor adds to cone- shaped features.

Drip stone column are stalagmites and stalactites connected.

Water Underground


Stalagmites

Stalactites

Dripstone Column

Water Underground

Cite: http://www.epidauros.freeserve.co.uk/slovenia/4stalagmites.jpg

Cite: http://www.sisutcliffe.co.uk/pix/spain_dec_03/stalagtites.jpg

Cite:http://www.suite101.com/files/articles/93000/93687/carlsbad_column1.jpg


View maps of major and minor aquifers of Texas by clicking here.

Water Underground

http://www.virdelldrilling.com/aquifers.htm


Porosity and permeability are related terms used to describe any rock or loose sediment. Both of these properties are essential to the formation of an aquifer. Describe the porosity and permeability in sand, gravel and clay.

Pre-AP Extension



1. What is the source of the water in an aquifer?

Let’s Review


Surface water percolates down through the recharge zone to

supply water to an aquifer.

Answer


2. What are some of the features formed by underground erosion

and deposition?

Let’s Review


Caves form by ground-water erosion. Stalagmites, stalactites, and dripstone columns form by

underground deposition.

Answer


Characteristics of the Atmosphere


Why is the atmosphere so important to the Earth?

What Do You Think?



Atmosphere is a mixture of gases that surround the Earth.

Protects you from the sun and

has oxygen.


Cite: http://www.wsd1.org/PC_Science/Weather/atmosphere.jpg



The atmosphere is made up of gases, solids and liquids.

Water is most common liquid in the atmosphere.

Cite: http://www.birdlife.org.za/resources/sustainable/Air/atmosphere_bird.jpg


Air pressure is the measurement of the force with which air particles push on a surface.



The atmosphere is held around the Earth by gravity.The gas particles are pulled towards the surface.There are fewer particles as you move away from the surface.



Altitude is the height of an object above the Earth’s surface.

As altitude increases, air pressure decreases.



Temperature changes as you move through the atmosphere due to the amount of sun’s energy that is absorbed by gases.




Cite:http://www.noaanews.noaa.gov/stories/images/atmosphere-regions.jpg



Troposphere makes up 90% of the mass of atmosphere.

It is the densest layer and the layer in which you live.

Cite: http://www.weatherquestions.com/troposphere.jpg



Stratosphere is above the troposphere

The air is very thin here and there is very little moisture.

The ozone is here that absorbs some of the sun’s harmful rays.

Temperature increases with altitude here.

Cite: http://www.policyalmanac.org/graphics/chartsn.gif


The mesosphere is above the stratosphere

It is the coldest layer and protects us from meteoroids. It burns up any substance that enters our atmosphere.



Thermosphere is a hot layer yet is doesn’t feel hot-because the particles move fast but are far apart.


Cite: http://www.spaceflightnow.com/delta/d289/images/timed.jpg



Ionosphere is the upper part of mesosphere and lower part of Ionosphere. This layer absorbs the sun rays, and the gas particles become electrically charged.

Cite:http://www.oma.be/BIRA-IASB/Public/Images/aurora2.gif


Use a scale to find the mass of a ball. Record the mass of the empty ball. Pump up the ball. Use a scale to find the mass of the ball filled with air. Compare the two masses. Does air have mass.


Activity



Review the layers of the atmosphere by clicking here.


http://www.enchantedlearning.com/subjects/astronomy/activities/label/atmosphere/

http://www.enchantedlearning.com/subjects/astronomy/activities/label/atmosphere/


Some scientist believe the Earth is warming up due to the greenhouse effect.

Measure temperatures in a model greenhouse and in a control as they are heated. Calculate the resulting temperature changes.

Pre-AP Extension



1. What cause air pressure?

Let’s Review


Air pressure is caused by gravity pulling molecules in the atmosphere

toward the Earth.

Answer


2. How can the thermosphere have high temperature but not feel hot?

Let’s Review


In the thermosphere, particles are moving quickly, but because they are

few and far apart, they cannot transfer much energy.

Answer


Atmospheric Pressure and Winds


What causes the wind to blow?

What Do You Think?



Wind is the movement of air as a result of different air pressures.

The greater the pressure difference, the stronger the wind.

Wind is caused by unequal heating of the Earth.



The unequal heating of the Earth makes pressure belts. The air rises or sinks making circular patterns on the Earth. These patterns are called convection cells.



Cite: http://www.eeb.uconn.edu/courses/eeb244/EEB244S02/Aphys4.gif


The way the wind blows depends on the rotation of the Earth.

The wind blows in a curved path due to the rotation of the Earth called the coriolis effect.



Cite: http://www.students.i.csbsju.edu/ijflenner/coriolis_effect.gif


Winds in the Northern Hemisphere curve to the right.

Winds in the Southern Hemisphere curve to the left.


Cite: http://www-nsidc.colorado.edu/arcticmet/images/factors/coriolis.gif


Cyclones are areas of low pressure. There is warm, less dense air at the center that rises.

Anticyclones are areas of high pressure. There is colder, denser air at the center that sinks.




Cite: http://rst.gsfc.nasa.gov/Sect14/3_cyclones.jpg


Local winds generally move short distances and can blow from any direction.Global winds are part of a pattern of air flow that moves across the Earth.



Trade winds blow at 30* latitude to the equator. (early sailors used the winds to sail from Europe to America).

Doldrums are around the equator where there is very little wind. (means foolish)

Horse Latitudes- are at 30*North and 30* south latitudes. Air sinks and there is very little air.



Westerlies are between 30* and 60* latitude. Flows towards the poles and helped ships return to Europe.

Polar Easterlies are between the poles and 60* latitude and is where cold air sinks.




Cite: http://www.esys.org/wetter/doldrums6.jpg


Jet stream is a narrow belt of high-speed winds that blow in the upper troposphere and lower stratosphere. The jet stream controls how storms move.


Cite: http://www.fishusa.com/FishErie/Captain/images/adams-jet-stream.jpg


Fill a large, clear plastic container with cold water. Tie the end of a string around the neck of a small bottle.Fill the small bottle with hot water. Add a few drops of red food coloring until the water has changed color.Without tipping the small bottle, lower it into the plastic container until it touches the bottom of the container. Observe what happens.

Activity




Explore the movement of the jet stream by

clicking here.


http://www.pbs.org/wgbh/nova/vanished/jetstream.html


1. How does the Coriolis effect affect the way wind moves?

Let’s Review


The Coriolis effect prevents winds from blowing in a straight path. Because of the Coriolis effect,

winds in the Northern Hemisphere curve to the right and winds in the

Southern Hemisphere curve to the left.

Answer


2. How do winds affect the weather?

Let’s Review


The warm, rising air in a low pressure area brings clouds and rain. The cool, sinking air in a high pressure area brings dry,

clear weather.

Answer

spring 2006, pflugerville isd © spring 2006, pflugerville isd, 6th grade 6th grade science

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