Download Teacher resources - Museum of Tropical Qld

Teacher resources
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CONTENTS
Astronomy Zone
Galaxy Gaze
4
Spinning Sun
6
The Solar System
8
Seasons in a Spin
10
Turn the Tides
12
Size of Planets
14
Atmosphere Zone
The Air Up There
16
Swirled World
18
What Weather?
19
Air Pressure
21
What’s in the Air?
23
Ozone
25
Surface Zone
Making Mountains
27
Deep Sea Glow
28
Urban Jungle
30
Hidden Depths
31
Food Pyramids
32
Plants in Space
34
Living Cells
36
Evolution
37
Landscape journey
39
2
Sub-surface Zone
Earthquake
40
Volcanoes
42
Core Samples
44
Surface to Core
45
Tectonic Plates
47
Fossil Finder
48
How Deep?
50
Exploring Earth
51
Dig a Hole
53
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Astronomy Zone
Exhibit:
Galaxy Gaze
Exhibit Messages
• The location of our Sun and other features in the Milky
Way.
• Little is known about our Milky Way due to high levels
of dust blocking the view for astronomers.
Exhibit Description
An illustration of the Milky Way with points (A, B, C and D)
marked on the area known as Orion’s Arm.
Visitors can look through toy telescopes to view the
astronomical features found at these points, including:
• the Sun
• Pleiades star cluster
• Orion nebula and
• Crab nebula.
Background Information
Our Solar System is a collection of planets, asteroids,
meteorites and one star (the Sun) found in the Milky Way
galaxy. Astronomers have viewed about 3000 different galaxies so far, but there may be
many billions of galaxies in the Universe!
The distance between the Sun and Pluto averages 5 913 520 000 kilometres. The distance
across the whole Milky Way is about 925 000 000 000 000 000 kilometres (about 100 000
light years). Imagine how long it would take to travel across many different galaxies!
The Milky Way’s nearest neighbour is the Sagittarius Dwarf galaxy (which is slowly being
‘swallowed up’ by the Milky Way). Ironically, astronomers can view nearby galaxies better
than our own Milky Way. This is because there is so much dust floating in the Milky Way, that
light cannot pass through.
Galaxies can be many different shapes, but the Milky Way is a spiral galaxy, believed to be
about 14 billion years old. Scientists are unsure whether the Milky Way’s bulging centre
contains a black hole or a mass of dust. Spiral arms extend out from the central bulge of the
Milky Way.
Images from the Galaxy Gaze exhibit
Nebulae are large collections of gas and dust where stars (and possibly planets) are being
formed. Go to http://www.aao.gov.au/images.html/captions/aat019.html for more information
on the Orion Nebula.
The Pleiades star cluster actually contains over 3000 stars, although the ‘seven sisters’ are
easiest to see with the naked eye. Go to
http://www.aao.gov.au/images.html/captions/uks018.html and
http://apod.gsfc.nasa.gov/apod/ap010506.html for more information on the Pleiades.
The Crab Nebula contains a neutron star that rotates about 30 times/second and releases
pulses of radio waves. Stars like these are called pulsars. Go to
http://www.aao.gov.au/images.html/captions/crab.html for more information.
More Information
Cosmic Distance Scale http://heasarc.gsfc.nasa.gov/docs/cosmic/cosmic.html
An Atlas of the Universe http://www.anzwers.org/free/universe/
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Natural History Magazine Out There April 2003
http://www.amnh.org/naturalhistory/0403/0403_outthere.html
Star Child:Galaxies
http://starchild.gsfc.nasa.gov/docs/StarChild/universe_level1/galaxies.html
Scientific American Ask the Experts 21 October 1999
How did scientists determine our location within the Milky Way galaxy--in other words, how do
we know that our solar system is in the arm of a spiral galaxy, far from the galaxy's center?
http://www.sciam.com/print_version.cfm?articleID=000AF71C-7E38-1C729EB7809EC588F2D7
Pre-or post-visit classroom activities
Background Research
Do Astronomers have photographs of the whole Milky Way or the whole Universe?
Have Astronomers photographed other galaxies close to the Milky Way? What is the nearest
galaxy to the Milky Way?
If you were an Astronomer taking photographs, what problems would you encounter?
Print out a picture of the Milky Way. Where is the Solar System in the Milky Way?
NASA Planetary Photojournal http://photojournal.jpl.nasa.gov/
Views of the Solar System (multiple languages) http://www.solarviews.com/ss.html
Welcome to the Planets http://pds.jpl.nasa.gov/planets/welcome.htm
David Malin images http://www.davidmalin.com/index.html
Anglo Australian Observatory images of the Universe http://www.aao.gov.au/images/
Astronomy Picture of the Day http://antwrp.gsfc.nasa.gov/apod/lib/aptree.html
An Atlas of the Universe http://www.anzwers.org/free/universe/
Links to Astronomy Education Activities http://antwrp.gsfc.nasa.gov/apod/lib/edlinks.html
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Exhibit:
Spinning Sun
Exhibit Message
As the Sun spins, it bulges slightly at its equator.
Exhibit Description
Turning a disc spins an attached ball, which represents the
spinning Sun.
At certain spinning speeds, the ball bulges around its middle,
representing an exaggerated model of the Sun’s equatorial
bulge.
Background Information
It’s no wonder our Solar System is named after the Sun. It is
such an important feature, being the only star in our Solar
System and containing nearly 99% of the Solar System’s total
mass.
The Sun could hold 1.3 million Earths alone!
The Sun is an extremely hot ball of ionised gas (mostly
hydrogen).
The Sun spins at different speeds at its equator compared to its poles. It spins once every 25
days at the equator and once every 36 days at the poles. Deep in its core, the Sun probably
rotates every 27 days.
As the Sun spins, it distorts or bulges slightly around its equator and becomes oblate (slightly
flattened at its poles). Scientists debate how large the bulge at the equator actually is, but
they believe it is mostly caused by centrifugal force or angular momentum. Angular
momentum is how easy or difficult it is to start or stop a spinning object such as the Sun.
The Sun even ‘sings’. Go to http://soi.stanford.edu/results/sounds.html and listen to the Sun’s
sound, caused by vibrations emitted from its boiling gases.
More Information
Solar Views
http://www.solarviews.com/eng/sun.htm
Scientific American Ask the Experts 4 January 1999
When a massive object--such as a star--spins, how is its gravitational field affected?
http://www.sciam.com/print_version.cfm?articleID=000758E6-3C7D-1C7184A9809EC588EF21
How the Sun Works http://science.howstuffworks.com/sun.htm/printable
Stanford Solar Centre http://solar-center.stanford.edu/index.html
Pre-or post-visit classroom activities
Background Research
The Sun bulges around its equator as it spins due to centripetal force. Information about
centripetal force can be read at
http://www.glenbrook.k12.il.us/gbssci/phys/mmedia/circmot/ucm.html
Activity
Cut a plastic or PET softdrink bottle in half. Take the bottom half of the bottle and punch small
holes in a line around its middle.
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Punch two holes opposite each other near the top, so a string handle can be threaded
through the holes. Place a soaked piece of material in the plastic bottle, so it reaches the
holes. Twist the string handle many times, then let it go and watch how water travels out
through the holes. The Sun’s equator has a tendency to travel outwards like this, but it is
pulled around (not allowed to escape like the water). Therefore, the Sun’s equator bulges.
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Exhibit:
The Solar System
Exhibit Message
• A model showing the order of planets in the Solar
System and the time they take to orbit the Sun.
Exhibit Description
A tabletop disc is divided up into eight separate rings with
eight knobs (labelled with planetary symbols to planets of
the Solar System, excluding Pluto).
Each ring is marked with Earth months or Earth years and
demonstrates how long it takes each planet to orbit the
Sun.
Planets closest to the Sun take months to complete their
orbit, while planets beyond Jupiter take many years to orbit
the Sun.
The planets move separately and independently in their
orbits, rather than moving in comparative orbits like a
standard orrery.
Background Information
Earthlings celebrate a birthday once a year. An Earth year (or sidereal year) is a measure of
how long it takes Earth to complete one orbit around the Sun (365.25 days). If you lived on a
planet further away from the Sun, your year would be longer. If you lived on Neptune, it would
take 165 Earth years to orbit the Sun—that’s a long time between birthdays! Mercury, which is
closest to the Sun, completes its orbit in about three months.
All nine planets orbiting the Sun have slightly elliptical orbits, although most are almost
circular. Pluto has the most elliptical orbit, but scientists are debating whether Pluto is a planet
or a very large meteorite. Pluto is actually smaller than Earth’s moon and takes 248 years to
orbit the Sun.
The speed at which planets orbit the Sun depends on their distance from the Sun. Earth’s
orbital speed is believed to be about 108 000 kilometres/hour, while Neptune moves at about
19 600 kilometres/hour.
Every planet with the exception of Mercury and Venus has at least one moon in orbit. Jupiter
has nearly 60 moons in orbit.
There are many asteroids and meteorites found orbiting the Sun, particularly in the KuiperBelt near Neptune or the Main Asteroid Belt between Mars and Jupiter.
As well as the planets orbiting the Sun, the whole Solar System moves in orbit around the
Milky Way. This means that every 226 million years, the Sun has moved in orbit around the
central bulge of the Milky Way, dragging the Solar System planets along with it.
More Information
NASA’s Jet Propulsion Laboratory
http://sse.jpl.nasa.gov/features/planets/planet_profiles.html
http://www.jpl.nasa.gov/solar_system/
http://sse.jpl.nasa.gov/features/planets/planetsfeat.html
Scientific American, Ask the Experts, 26 October 1998 How fast is the earth moving?
http://www.sciam.com/print_version.cfm?articleID=000D358F-79AC-1C729EB7809EC588F2D7
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Pluto as a Planet? 21 October 1999
http://www.sciam.com/print_version.cfm?articleID=0009D053-74A9-1C729EB7809EC588F2D7
Animation of Solar System orbits (including Quaoar)
http://www.gps.caltech.edu/~chad/quaoar/quaoarorbit.gif
Views of the Solar System http://www.solarviews.com/eng/homepage.htm
The Nine Planets http://seds.lpl.arizona.edu/nineplanets/nineplanets/nineplanets.html
Astronomy for Kids http://www.dustbunny.com/afk/
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Exhibit:
Seasons in a Spin
Exhibit Message
• How the Earth's tilted axis and orbit around the Sun
creates seasons on Earth by changing the angle of
sunlight hitting Earth.
Exhibit Description
A model Earth can be moved by hand in orbit around a model
Sun. Pictures showing the season in each hemisphere when
the Earth is at certain points of its orbit are shown on the
tabletop.
The model shows how the Earth is tilted more directly towards
or away from the Sun at different times of the year at different
points of its orbit around the Sun.
The graphic panel also addresses common misconceptions
about why seasons occur on Earth and describes how the
angle of sunlight hitting Earth is responsible for the seasons.
Background Information
Different parts of the world may have only two seasons (wet and dry), while other parts of the
world have four seasons (spring, summer, autumn, winter) through to eight seasons! However
many seasons you have in your part of the world, the change in temperature and length of
daylight is caused by the angle at which sunlight hits the Earth. Seasons are not caused by
how close or far away the Earth is positioned from the Sun.
Earth is tilted on an axis and moves in orbit around the Sun once a year. This points the
northern and southern halves (called the hemispheres) more directly towards or away from
the Sun at different times of the year. This affects the angle at which sunlight hits the Earth’s
surface.
In June, the northern hemisphere is tilted towards the Sun, so the Sun is higher in the sky.
The length of time that sunlight hits the northern hemisphere is also longer (the daytime
increases). The angle of sunlight and longer days cause a greater heating effect on the
ground, so temperatures rise, and the northern hemisphere has summer.
The southern hemisphere is tilted away from the Sun during June, so the Sun is lower in the
sky. This means that sunlight hits the southern hemisphere at a sharper angle, so it spreads
out and has less of a heating effect. The length of time that sunlight shines on the southern
hemisphere is also much less, giving shorter days and less time for the ground to heat up.
This causes the colder temperatures of winter.
In December, the Earth has moved in its orbit around the Sun and the southern hemisphere is
now pointed towards the Sun and the northern hemisphere is pointed away from the Sun.
This means the northern hemisphere receives sharply angled sunlight and shorter periods of
sunlight, so they experience winter. At the same time, the southern hemisphere is pointed
towards the Sun, so it receives sunlight directly overhead for longer periods of time which
causes summer.
You may have heard of days known as ‘solstice’. These days represent a rough ‘mid-way’
point for a season, where the shortest and longest days occur. Around 21 June, the southern
hemisphere has its shortest period of sunlight (winter solstice) while the northern hemisphere
has its longest period of sunlight (summer solstice). Then on 21 December, the Earth has
moved in its orbit around the Sun and the situation is reversed, so the southern hemisphere
has summer solstice, and the northern hemisphere haswinter solstice.
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The days known as ‘equinox’ represent days when the Sun is overhead at the equator and all
parts of the Earth have a day and night of equal length. Neither the northern or southern
hemispheres are tilted more directly toward the Sun and each hemisphere has sunlight for
about 12 hours. Equinox days occur around 21 March and 22 September when the Earth has
moved in its orbit around the Sun.
More Information
Bad Astronomy What Causes Seasons http://www.badastronomy.com/bad/misc/seasons.html
NASA Kids, Earth’s Seasons http://kids.msfc.nasa.gov/earth/seasons/EarthSeasons.asp
Earth's Seasons, Equinoxes, Solstices, Perihelion, and Aphelion 1992-2020
http://aa.usno.navy.mil/data/docs/EarthSeasons.html
Pre-or post-visit classroom activities
Background Research
Use NASA website about Seasons http://kids.msfc.nasa.gov/earth/seasons/seasons.htm
Bad Astronomy website http://www.badastronomy.com/bad/misc/seasons.html
Activity
Use an electric light globe (Sun) and a globe of the Earth in a darkened room to represent
how sunlight shines on the Earth’s surface as it moves in orbit around the Sun (torch). Does
the angle of sunlight change as it hits the hemispheres?
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Exhibit:
Turn the Tides
Exhibit Messages
• Two low and two high tides occur on Earth every 24
hours.
• Tides are caused by the Moon orbiting the Earth.
Exhibit Description
Two tabletop graphics show:
• tidal/water bulges with the Moon orbiting Earth and
• the Earth from the perspective of looking down onto the
North pole.
As visitors spin the Earth graphic, the tide/Moon graphic
underneath moves in a ratio of 1:28 (moon orbit : Earth spins).
This demonstrates how two matching high tides and two
matching low tides occur on Earth roughly every 24 hours.
Background Information
It’s complicated trying to explain why tides occur on Earth. Many
people don’t realise the way tides occur and how a high tide on one side of the Earth is
matched by another high tide on the opposite side of the Earth.
The high tide closest to the Moon tends to be taller than the matching high tide on the other
side of the Earth (which is a little flatter). About six hours later in the same area, a low tide
occurs and the water level drops.
Tides are easiest to see as the rising and falling water levels along a beach. They are mostly
caused by the Moon almost 384 000 kilometres away from the Earth and are partly caused by
the gravitational pull of the Sun as well. The Moon has a greater gravitational effect, because
it is closer to Earth than the Sun.
As the Moon orbits Earth every 27.3 days, it ‘pulls’ on the Earth, causing a gravitational pull
(or tidal force). At high tide, water moves further up the shore and the ground rises 10 to 30
centimetres (although you can’t feel it rise under your feet).
Tides occur slightly ahead of the Moon’s orbital path because the Earth rotates faster than the
Moon orbits. This tidal bulge slows down the Earth’s rotation and drives the moon further
away.
More Information
Phil Plait’s Bad Astronomy Misconceptions about Tides
http://www.badastronomy.com/bad/misc/tides.html
New Scientist, The Last Word, Tides are caused by the Moon and the Sun and contain a lot
of energy, but where does it all come from?
http://www.newscientist.com/lastword/article.jsp?id=lw548
New Scientist, The Last Word, Can anyone explain in simple and common-sense terms why
there is simultaneously a high tide on both sides of the Earth?
http://www.newscientist.com/lastword/article.jsp?id=lw55
Myths about gravity and tides article from The Physics Teacher. 37, October 1999, pp. 438441.
Requires Adobe Acrobat Reader to view.
http://www.jal.cc.il.us/~mikolajsawicki/tides_new2.pdf
Stanford Solar Center – What is the Sun and the Moon's relationship to the Earth tides?
http://solar-center.stanford.edu/FAQ/Qtides.html
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Scientific American Ask the Experts 21 October 1999
The Moon’s Rotation and Revolution
http://www.sciam.com/print_version.cfm?articleID=0000976C-7D8F-1C729EB7809EC588F2D7
Pre-or post-visit classroom activities
Background Research
Choose the nearest coastal area to your town.
What other body apart from our Moon controls tides on Earth?
How many hours pass between low and high tides in one place?
Tide Predictions for Australia and the Pacific
http://www.ntf.flinders.edu.au/TEXT/TIDES/tides.html
Tidal Predictions in the United States of America http://co-ops.nos.noaa.gov/tp4days.html
Australia-wide tidal charts http://www.coastalwatch.com/tides.asp
World-wide tide charts http://www.tides.info/ (type in location)
13
Exhibit:
Size of Planets
Exhibit Message
• A scaled comparison of the size of planets in our Solar System.
Exhibit Description
Transparent discs each have scaled pictures of individual planets with planetary symbols
printed on them.
The planets are not bound to their existing order in the Solar System. This allows users to
swap the discs around and compare the size of any two or more planets in the Solar System,
such as Pluto against Earth or Jupiter against Mercury, etc.
Background Information
It’s difficult to understand how large our Solar System really is. Pluto is usually 5 913 520 000
kilometres away from the Sun.
It’s surprising to realise how large our Sun actually is compared to the planets as well. If the
Sun was shrunk to the size of a bowling ball, Earth would be the size of a peppercorn 21
metres away and Jupiter would be the size of a large marble 113 metres away.
The first four planets (Mercury, Venus, Earth and Mars) are close to the Sun. Then there is a
large gap (filled with a belt of meteorites) before reaching the Solar System’s two largest
planets (Jupiter and Saturn).
Some of the Moons found orbiting around various planets can be quite large. Several moons
(found orbiting Earth, Jupiter, Saturn and Neptune for example) are larger than Pluto.
The actual size of each planet and its distance from the Sun is listed in the table below.
Planets
Planet diameter (kilometres)
Distance from Sun (kilometres)
Mercury
4 878
57 909 175
Venus
12 102
108 208 930
Earth
12 756
149 597 890
Mars
6 794
227 936 640
Jupiter
142 984
778 412 020
Saturn
120 536
1 426 725 400
Uranus
51 118
2 870 972 200
Neptune
49 528
4 498 252 900
Pluto
2 390
5 906 376 200
More Information
Exploratorium’s Build a Solar System http://www.exploratorium.edu/ronh/solar_system/
NASA Jet Propulsion Laboratory Solar System Exploration: The Planets
http://sse.jpl.nasa.gov/features/planets/planet_profiles.html
http://www.jpl.nasa.gov/solar_system/
Views of the Solar System http://www.solarviews.com/eng/homepage.htm
Pre-or post-visit classroom activities
Activity and Background Research
Is it possible to build a small scale Solar System, showing the size planet and their distance
from the Sun at the same time? It’s harder than you think! Use The Exploratorium’s Build a
Solar System website http://www.exploratorium.edu/ronh/solar_system/.
14
Students can individually or in small groups research and practice marking out a scaled
model of the Solar System. They will soon realise how difficult it is to show planet size and
their distance from the Sun in the same model.
15
Atmosphere Zone
Exhibit:
The Air Up There
Exhibit Message
• The different layers of Earth’s atmosphere and the natural features and aircraft that
can be found in each layer
Exhibit Description
Separate acrylic arches are layered over a small globe of the Earth, representing layers of
Earth’s atmosphere.
As each arch is flipped down or up, they reveal images of aircraft that fly in that particular
layer or natural phenomena such as lightning, sprites, meteors, etc.
The graphic panel lists each layer, the aircraft and natural phenomena found in that layer and
the layer’s true thickness (which cannot be shown to scale on the exhibit).
Background Information
Earth is covered with a thin ‘shell’ of gas called atmosphere. If you reduced Earth to the size
of a grapefruit (13 centimetres across), the atmosphere would only be 2 millimetres thick. The
Earth is really about 12 000 kilometres in diameter and the atmosphere extends about 500
kilometres from the Earth’s surface. Without the atmosphere, Life would not exist on Earth.
Each layer of atmosphere varies in temperature, thickness and the gases it contains. There is
a kind transition zone between the layers where one layer ‘blends’ into the next.
The layer closest to Earth’s surface is called the troposphere. Most weather patterns occur in
this layer, which is only about 12 kilometres high. Mount Everest, which is about 8 kilometres
high, is still located in this layer.
The next layer—the stratosphere—is important for keeping the troposphere warm. It also
contains ozone gas which absorbs ultraviolet (UV) radiation, preventing too much UV from
reaching the Earth’s surface. The stratosphere also contains dust from volcanic activity and
human pollution. This dust can change the temperature on Earth’s surface slightly.
There’s plenty of colourful action in the upper layers! Layers above the stratosphere
(mesosphere and thermosphere) have ionised or charged gases and are called the
ionosphere. The ionised gases allow spectacular natural events such as sprites to flash
across the sky. When ionised or charged gases collide, they release brilliant flashes of red or
blue light.
Auroras (also known as the northern and southern lights) are other colourful displays of light,
which shift in sheets across the skies. Scientists are unsure why auroras occur, but it may be
due to an interaction between the Earth’s magnetic field and solar winds (from our Sun).
16
Name of
atmospheric layer
Size of atmospheric
layer
Human-built aircraft
found in this layer
Troposphere
12 kilometres thick
Commercial aircraft
Stratosphere
38 kilometres thick
Concorde
Weather balloons
Mesosphere
30 kilometres thick
Thermosphere
420 kilometres thick
International Space
Station
Exosphere
Blends into space
Space Shuttle
Natural features
found in this
layer
Clouds and most
weather occur here.
Contains 85% of the
atmosphere’s mass.
Ozone prevents most
Ultraviolet (UV)
radiation from
reaching Earth’s
surface.
Sprites (a type of
lightning) occur here.
Meteors (‘shooting
stars’) burn up when
entering this layer.
Auroras occur in this
layer.
More Information
Earth’s Atmosphere (NASA) http://liftoff.msfc.nasa.gov/academy/space/atmosphere.html
Scientific American News 14 March 2002, Blue Jets May Link Thunderstorms to the
Ionosphere
http://www.sciam.com/print_version.cfm?articleID=0000E922-F54A-1CCF
B4A8809EC588EEDF
Scientific American News, 17 January 2003, Wriggling Energy Source May Power Auroras
http://www.sciam.com/print_version.cfm?articleID=0006F3CF-0271-1E268B3B809EC588EEDF
Scientific American News 26 June 2003, Gigantic Jets Connect Thunderclouds to the
Ionosphere
http://www.sciam.com/print_version.cfm?articleID=00052B00-FA6A-1EF9BA6A80A84189EEDF
New Scientist. The Last Word. Why do aeroplanes fly higher than Mount Everest even where
there are no mountains?
http://www.newscientist.com/lastword/article.jsp?id=lw741
New Scientist, The Last Word. 08 September 2001, Light show
http://archive.newscientist.com/secure/article/article.jsp?rp=1&id=mg17123077.700
Questions and Answers about Aurora (NASA)
http://image.gsfc.nasa.gov/poetry/ask/aurora.htm
Sprite Chasing from the Back Porch http://www.fma-research.com/Papers&presentations/sprview-1.html
New Scientist, Inside Science, No. 86, 9 December 1995 Structure of the Earth's atmosphere
17
Exhibit:
Swirled World
Exhibit Messages
• How the Earth's spin and landforms generate weather patterns (Coriolis force).
Exhibit Description
A clear Perspex globe is filled with a soapy solution and mounted on a spinning pole.
When users spin the globe at different speeds or change the globe’s direction of spin, they
can observe swirling patterns being created in the viscous soap— particularly around the
equator.
Background Information
The Earth has many swirling currents—underground, in the oceans and in the atmosphere.
Air near the ground and water in the oceans gets dragged along with the Earth as it spins on
its axis. This creates swirling currents in the ocean and in the air. Air currents may strengthen
and grow into typhoons and hurricanes. These currents are caused by the Coriolis force
(named after an 18th to 19th century French mathematician).
Imagine you’re floating in space, looking down on Earth in line with the equator. You would
‘see’ air and water get dragged in a clockwise direction in the southern hemisphere and in an
anticlockwise direction in the northern hemisphere as the Earth spins.
Air and water near the equator have a greater distance to move as the Earth spins than air
and water at the poles. This means equatorial air and water will be dragged along faster in a
clockwise/anticlockwise direction.
Low pressure systems of air (creating storms) will follow these clockwise/anticlockwise
patterns and move from the equator towards the poles. Storms grow stronger as they move
towards the poles and they may become hurricanes.
There is a strong urban myth that water drains through plugholes in an
anticlockwise/clockwise direction in the northern and southern hemisphere due to the Coriolis
force. This is untrue, even when ‘demonstrated’ by tourist operators who step on either side of
the equator with a pan of water. They’re simply using tricks of the hand and eye. Water drains
from a sink in a pattern based on the shape of the sink and how the water starts moving.
More Information
New Scientist The Last Word Which way to turn?
http://www.newscientist.com/lastword/article.jsp?id=lw445
Bad Coriolis http://www.ems.psu.edu/~fraser/Bad/BadCoriolis.html
Scientific American, Ask the Experts, 21 July 1997, What causes the high-speed winds, or "jet
stream," in the stratosphere?
http://www.sciam.com/print_version.cfm?articleID=000D2B8B-DAF4-1C719EB7809EC588F2D7
Scientific American, Ask the Experts. 28 January 200, Does water flowing down a drain spin
in different directions depending on which hemisphere you're in?
http://www.sciam.com/print_version.cfm?articleID=00069EE7-6D24-1C719EB7809EC588F2D7
Rotating Frames of Reference on Earth and in Space http://wwwspof.gsfc.nasa.gov/stargaze/Srotfram.htm
Coriolis force http://observe.arc.nasa.gov/nasa/space/centrifugal/centrifugal7a.html
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Exhibit:
What Weather?
Exhibit Message
• Predicting the weather (and judging the best clothing
to wear) by observing clouds.
Exhibit Description
This is a quiz, testing knowledge of cloud types and weather
forecasting.
Users read information about clouds, then look at unlabelled
cloud photos on the tabletop exhibit. For each cloud picture, a
ball must be placed next to a picture of the clothing that should
be worn (snow gear, wet weather clothing, light sunny clothing,
etc) if those clouds are in the sky.
Answers can be checked by pushing a lever and checking which balls stay in place (indicating
an incorrect answer).
Background Information
There are ten main types of clouds, found up to twelve kilometres high in the troposphere.
The clouds are named using combinations of Latin words which describe their shape, size
and how high or low they are found in the troposphere.
Cirrus = hair-like
Cumulus = heaped
Alto = height
Nimbus = bringing rain
Stratus = layered
How do clouds form?
Air contains water vapour (gas). As air cools down, the water vapour condenses to form water
droplets.
Clouds tend to form and stay in air that moves upwards. As air rises in an updraft, it
decreases in pressure, cools down and expands. The water vapour condenses to form clouds
more easily at colder temperatures.
Different types of clouds are formed depending on how the temperature changes with height
and atmospheric turbulence.
Clouds that bring light rain or drizzle tend to form where the air moves weakly upwards over a
large area of sky. Steady or heavy-rain clouds form in the sky where the updraft is much
faster.
Clouds look grey just before rainy weather because they are more tightly packed with water
droplets, and less sunlight can pass through. As clouds grow taller, they appear more grey,
particularly at their base.
More Information
Scientific American, Ask the Experts 12 September 2002, Turbulence Within Clouds Brings
Rain.
http://www.scientificamerican.com/print_version.cfm?articleID=0008C89D9B6C-1D7F-90FB809EC5880000
Scientific American, Ask the Experts, 24 January 2000, Why do clouds turn grey before it
rains?.
http://www.sciam.com/print_version.cfm?articleID=000350D0-D08A-1C71-
19
9EB7809EC588F2D7
Scientific American, Ask the Experts 25 June 2001,How do water droplets in clouds adhere?
http://www.sciam.com/print_version.cfm?articleID=0003A4FA-CEF2-1C719EB7809EC588F2D7
Bureau of Meteorology
http://www.bom.gov.au/info/clouds/
http://www.bom.gov.au/lam/Students_Teachers/animations/cloudzstart.s
html
Bad Meteorology.
http://www.ems.psu.edu/~fraser/Bad/BadClouds.html
New Scientis,t The Last Word - Weather
http://www.newscientist.com/lastword/results.jsp?category=Weather
Pre-or post-visit classroom activities
Background Research
Use BOM website Cloud Quiz
http://www.bom.gov.au/lam/Students_Teachers/animations/cloudzstart.shtml
Activity
Make a wet/dry indicator from pipe cleaner and cobalt chloride solution. Soak the pipe
cleaners in the cobalt chloride solution and let them dry. When the pipe cleaners are pink, this
indicates dry weather. When the pipe cleaners are blue, this represents humid or rainy
weather. Shape the pipe cleaners into a human form, design and paint a sign “If I’m pink it’s
dry. If I’m blue, it’s wet.”
Collect weather predictions from local newspapers. Draw up a calendar chart of days and
predicted weather. Write on the chart each day what cloud type was present. Next day, write
the weather that was actually experienced.
20
Exhibit:
Air Pressure
Exhibit Message
• Air pressure changes as you reach different levels of the Earth’s atmosphere.
Exhibit Description
While pressing a button, users move a column up and
down, to remove air from a glass dome.
The removal of air (and drop in air pressure) can be seen
by an expanding rubber diaphragm. This represents how
air pressure decreases as you travel higher up into the
atmosphere (explained on the graphic panel).
Background Information
Air is pressing down on you all the time. Living on Earth’s
surface, we experience the highest air pressure or
atmospheric pressure.
Air is pulled to the Earth’s surface by gravity, so most air
is found six kilometres above Earth’s surface. This means
the atmosphere is most dense near the Earth’s surface
where the atmospheric pressure is highest.
As you travel higher up in to the atmosphere, the air
pressure decreases. By the time you travel 5.5 kilometres
high into the sky, the air pressure has almost halved.
If you climb up Mount Everest, nearly 8 kilometres high,
the air pressure drops to one third of the air pressure at
sea level (30 kilopascals versus 96 kilopascals at sea level).
When you drive up a mountain, or fly in a plane, your ears may ‘pop’ because the air pressure
is changing. As you climb higher up into the sky, air pushes less forcefully on your ear
membrane. This allows air inside your middle ear to expand. This expanding air escapes
through a tube leading to your throat, creating that ‘popping’ feeling.
Changes in air pressure (caused by air being warmed up and cooled down) are also
important for weather patterns. When the air pressure changes, it can be measured using a
barometer, which can then predict weather patterns. High pressure systems are where air is
sinking (generally bringing fine weather). Low pressure systems involve warm air rising,
cooling down and forming clouds (which usually bring rainy weather).
More Information
Air Pressure and weather systems
http://www.bom.gov.au/lam/Students_Teachers/pressure.shtml
Atmospheric Pressure http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/prs/def.rxml
Pressure on Earth, Hypertextbook
http://hypertextbook.com/facts/2001/JaredGoldberger.shtml
Scientific American, The Amateur Scientist, Making Experiments out of Thin Air. Carlson, S.
1998. April:98-99
21
Pre-or post-visit classroom activities
Activity
Fill a flat-rimmed glass until it is almost overflowing. Gently slide a piece of cardboard or thin
plastic across the top of the glass, so it sticks to the glass rim. While holding the cardboard
firmly over the mouth of the glass, turn the glass of water upside down and remove your hand
holding the cardboard in place. Does the cardboard fall off or stay in place? If the card is
staying in place, what could possibly be holding it there?
22
Exhibit:
What’s in the Air?
Exhibit Message
Which gas is mostly commonly found in Earth’s atmosphere—nitrogen or oxygen?
Exhibit Description
Users hold up a tray and complete a pie-chart puzzle, using pieces representing oxygen gas
(blue) or nitrogen gas (red).
While many people may think that Earth’s atmosphere contains mostly oxygen, by completing
the puzzle, users may be surprised to discover that nitrogen gas is the most common
component of air.
Background Information
Earth’s atmosphere contains about 78% nitrogen gas and 21% oxygen gas.
The remaining 1% consists of many different trace gases.
Earth’s atmosphere has changed greatly since Earth formed more than four billion years ago.
The level of oxygen gas in the air today is believed to be higher than levels billions of years
ago. Scientists believe oxygen levels rose when living organisms called cyanobacteria
(formerly known as blue-green algae) evolved more than three billion years ago.
Cyanobacteria carry out a chemical reaction that uses sunlight to convert carbon dioxide and
water into glucose and oxygen. This chemical reaction is called photosynthesis.
The remaining 1% of trace gases includes carbon dioxide, water vapour, neon, helium,
methane, krypton, carbon monoxide, sulfur dioxide, hydrogen, ozone, xenon, nitrogen
dioxide, radon, nitrogen dioxide, nitrous oxide and nitric oxide, etc. The different ‘nitro’ gases
are part of the nitrogen cycle, and help to recycle nitrogen from decomposing plants and
animals so it can be used again to build proteins in living things.
Although many gases in Earth’s atmosphere are found in small amounts, they can still have a
powerful effect on the Earth’s surface. For example, ozone is very important for preventing
too much ultraviolet radiation from reaching Earth’s surface. Carbon dioxide and methane
help to keep the Earth warm enough for Life to thrive. If levels of carbon dioxide, methane and
water vapour become too high, Earth may become overheated.
More Information
Earth’s Atmosphere (NASA)
http://liftoff.msfc.nasa.gov/academy/space/atmosphere.html
Where did Earth’s oxygen come from?
http://www.sciam.com/print_version.cfm?articleID=000E9FDF-CBC1-1C719EB7809EC588F2D7
Scientific American News 6 August 2001, New Theory Explains How Earth's Early
Atmosphere Became Oxygen-Rich.
http://www.sciam.com/print_version.cfm?articleID=000304B7-4A8F-1C60B882809EC588ED9F
New Scientist, The Last Word. Did all the oxygen in Earth's atmosphere come from
photosynthesising plants? If not, where did it come from?
http://www.newscientist.com/lastword/article.jsp?id=lw969
Why is Nitrogen the most common element in the Earth’s atmosphere?
http://www.soest.hawaii.edu/GG/ASK/atmo-nitrogen.html
Scientific American Ask the Experts 21 October, 1999, When did eukaryotic cells (cells with
nuclei and other internal organelles) first evolve? What do we know about how they evolved
23
from earlier life-forms? http://www.sciam.com/print_version.cfm?articleID=000C32DD-60E11C72-
9EB7809EC588F2D7
Education Materials (
24
Exhibit:
Ozone
Exhibit Message
• Explores facts and myths about the ozone ‘hole’, while testing visitor’s knowledge.
Exhibit Description
A panel of information describes the ozone ‘hole’ and addresses some common
misconceptions about ozone thinning.
After reading the ozone information, users can take the ozone quiz. There are four questions
or statements, labelled A, B, C and D. For each statement, a ball must be placed under the
TRUE or FALSE column on the tabletop.
Answers are checked by pushing a lever. Balls either stay in place (indicating a correct
answer) or fall through (indicating an incorrect answer).
Background Information
Ozone is a gas mostly found 15 to 30 kilometres above the Earth’s surface in the
stratosphere. Some ozone is found at ground level as well.
Ozone molecules are made of three oxygen atoms joined together. The oxygen gas we
breathe has two oxygen atoms joined together. Unlike normal oxygen, ozone is blue, has a
strong odour and is harmful to breathe in large amounts.
Ozone is important in the stratosphere because it absorbs some ultraviolet
(UV) radiation from the Sun before it reaches Earth’s surface. Some UV is needed by living
things, but too much UV radiation can damage skin (causing cancer), eyes (causing
cataracts) and animal immune systems.
High UV levels also damages crops.
Over the last 50 years Earth’s whole ozone layer has thinned.
The ozone layer becomes especially thin over Antarctica during summer.
This has become known as the ozone hole, although the whole ozone layer is actually
becoming thinner, rather than developing a gaping hole in one area.
The main reason for ozone layer depletion is the use of chemicals that contain chlorine atoms
such as chlorofluorocarbons (CFCs) and other halons (such as bromine). When CFCs reach
the stratosphere, UV radiation breaks them apart to release free radicals (such as chlorine
atoms). These free radicals destroy ozone molecules, and the ozone layer is gradually
destroyed. Because compounds like CFCs take a long time to break down it will be at least 50
years before the ozone layer is restored.
People often get confused between the ozone hole and the greenhouse effect. Although
ozone is a greenhouse gas (similar to carbon dioxide), the ozone hole (allowing more UV
radiation through than usual) is different to the greenhouse effect (temperatures on Earth
increasing due to higher carbon dioxide, methane and water vapour levels).
More Information
Ozone Depletion: Myth v Measurement
http://www.epa.gov/ozone/science/myths.html
Ozone Information, Bureau of Meteorology
http://www.bom.gov.au/lam/Students_Teachers/ozanim/ozoanim.shtml
NASA Ozone information
http://www.nas.nasa.gov/About/Education/Ozone/ozone.html
The Australian Greenhouse Office. The difference between the greenhouse effect and ozone
depletion.
25
http://www.greenhouse.gov.au/education/what.html#ozone
Misconceptions in Australian Students’ Understanding of Ozone Depletion
http://www.met.sjsu.edu/~cordero/research/Papers/MSIE_paper.pdf
CSIRO Atmospheric Research
http://www.dar.csiro.au/information/ozone.html
Scientific American, Ask the Experts 30 June 2003, Why do ozone-depleting chemicals not
diffuse evenly (and cause a general thinning of the ozone layer) but instead cause holes at
the poles?
http://www.sciam.com/print_version.cfm?articleID=00069073-51631EFBBA6A80A84189EEDF
26
Surface Zone
Exhibit:
Making Mountains
Exhibition Message
• How movement of the Earth’s crust causes the formation of some mountains on the
Earth’s surface.
Exhibition Description
Wooden blocks that slide along tracks are used to model two types of mountain formation
where:
1. tectonic plates ‘crumple’ up against each other such as the Himalayan mountains or
2. one tectonic plates slips under another, pushing the top plate up into a mountain range
such as the Andes mountains.
Background Information
Mountains form on Earth through volcanic activity and when tectonic plates collide.
The plates may collide and crumple up against each other (Himalayan mountains), or one
plate can slide under another plate, pushing the top plate upwards (Andes mountains). This
mountain building happens over many millions, even billions of years as the tectonic plates
shift around due to continental drift.
Himalayan Mountains
The Himalayan Mountains between China and Tibet (including Mount Everest) were formed
where two continental plates collided head-on and the plates ‘buckled’ upwards or sideways
to form mountains.
The building of the Himalayas started about 50 million years ago, when the Indian tectonic
plate had drifted up and collided with the Eurasian tectonic plate. The greatest growth of the
Himalayas has occurred over the last 10 million years. The Himalayas continue to grow today,
and Everest gets higher each year.
Andes Mountains
The Andes Mountains are being formed where the Nazca tectonic plate is sinking under the
South American tectonic plate (a process called subduction).
The Nazca plate is an oceanic plate (covered with water). As it sinks under the South
American continental plate (the South American land mass), it causes large earthquakes and
forces the South American plate upwards into a mountain range.
The Nazca oceanic plate is thought to be more dense, so it sinks under or subducts the
lighter South American continental plate.
Scientists are unsure whether the magma that fuels the volcanic activity around the Andes
comes from the melted Nazca plate, or other sources.
More Information
Formation of Folds in the Earth
http://www.earth.monash.edu.au/OpenDay/goldendyke.html
United States Geological Survey—This Dynamic Earth
http://pubs.usgs.gov/publications/text/understanding.html
United States Geological Survey—Convergent Plate Boundaries
http://geology.wr.usgs.gov/docs/parks/pltec/converge.html
27
Exhibit:
Deep Sea Glow
Exhibition Message
• Examples of deep-sea creatures that use bioluminescence to attract prey.
Exhibition Description
Images of hatchet fish, siphonophore and dragon fish are printed on a tabletop disc. The
images include phosphorescent vinyl. While the images are exposed to light the
phosphorescent areas of the print ‘absorb’ light energy.
Users look down through a viewing scope and turn the tabletop disc so each animal image
comes into view. The viewing scope is darkened, so the phosphorescent vinyl glows,
representing the bioluminescent glow these animals emit in the deep sea.
Users can compare the appearance of the animals in the light and dark.
Background Information
Deep down in the ocean is very dark because little sunlight reaches the depths. Sunlight is
white light, made up of seven colours—red, orange, yellow, green, blue, indigo and violet (the
colours of a rainbow).
As sunlight travels down into the ocean, each colour is absorbed in turn until only violet light
reaches water a few hundred metres deep.
This makes the lower depths of oceans very dark. So, plants and animals at these depths
produce a blue-green or bioluminescent light.
Bioluminescent light can be used:
• as a lure to attract prey
• to communicate with other members of their species
(possibly formating) or
• to cancel out their silhouette against the water’s surface to
predators looking up from below.
Bioluminescent light is created by a chemical reaction
between luciferin, oxygen and the enzyme luciferase. It is
different to phosophorescence (which absorbs light, then
emits light when it is dark). Bioluminescence is also displayed
in land animals such as fireflies.
The animals in the Deep Sea Glow exhibit in Earth Quest are
listed below.
• Hatchetfish live in open water. Some species have rows of silver oblong patches (light
reflectors) and pink, light-producing organs facing downwards, so their silhouette is hidden
from predators beneath them (so their silhouette is invisible to predators looking from
below)
• Siphonophores are a jelly-like colony of single celled animals. Collections of
siphonophores can reach up to 40 metres. Their bioluminescent tentacles seem to lure
prey.
• Female dragonfish have a glowing tip on their chin barbel that may attract prey.
More Information
NORFANZ Deep Sea Voyage
http://www.oceans.gov.au/norfanz/extracreatures.htm
28
Scientific American Ask the Experts 19 April 1999 What is chemiluminescence?
http://www.sciam.com/print_version.cfm?articleID=0005A1A8-5B7F-1C729EB7809EC588F2D7
Australian Museum Online Black Dragonfish
http://www.amonline.net.au/fishes/fishfacts/fish/iatlan.htm
Image Quest Marine Siphonophores
http://www.imagequest3d.com/catalogue/jellyfish/siphonophorae.htm
BBC Blue Planet Dragonfish
http://www.bbc.co.uk/nature/blueplanet/factfiles/fish/dragonfish.shtml
The Bioluminescence Web Page
http://www.lifesci.ucsb.edu/~biolum/
Glow Exhibit http://www.glowexhibit.com/ HBOI More About Bioluminescence
http://www.biolum.org/
Pre-or post-visit classroom activities
Activity
Make papier mache models of deep sea creatures. Use fluorescent tape (available from
hardware stores for placing on light switches, etc) or bioluminescent paint to decorate the
creatures.
Deep Sea Fish activity http://marinediscovery.arizona.edu/lessonsF00/tube_worms/2.html
29
Exhibit:
Urban Jungle
Exhibit Message
• Some animals have adapted to find homes in natural and urban environments.
Exhibit Description
This ‘lift and reveal’ exhibit is particularly targeted at young children and their adult
companions.
Children search for six different animals in an urban scene by lifting panels.
On a similar forest scene panel, children can search for the same six animals positioned in
the trees, grass and water.
Background Information
When cities grow, humans build houses, roads, pathways and grassy spaces over natural
areas. This is called urban sprawl and it is creating problems for the environment.
Humans are clearing grasslands and forests at a fast rate. Each year an area of forests about
the same size as 81 million Olympic-sized pools (25.2 million acres) is cleared around the
world.
Animals usually live in small areas with special conditions called niches. Once their niche has
been built over or removed, plants and animals need to find a new place to live. Some
animals move to other forested areas. Other animals have no choice but to create a new
home in the human city.
Urban sprawl creates environmental problems such as:
• reducing the number of places where animals can live, so some animals
becoming extinct
• creating large volumes of water run-off because roads and cement
don’t absorb rain as well as soil and planted areas
• increased light, noise and chemical pollution and
• other environmental problems such as salinity and soil erosion.
As the population increases and more people move to city areas, urban planners need to
accommodate people without expanding the city limits too much. They may choose to limit
the amount of land for houses and control how roads and drains are built.
Scientists can keep an eye on urban sprawl by counting the number of plants and animals in
an urban area and studying satellite images of city areas.
More Information
Nature 20 August 2002 Urban sprawl creates unwilling neighbours
http://www.nature.com/nsu/020819/020819-1.html
New satellite maps provide planners improved urban sprawl insight
http://www.globaltechnoscan.com/6thJune-12thJune01/satellite.htm
Urban Ecology http://www.urbanecology.org/
Food and Agriculture Organisation of the United Nations
http://www.fao.org/forestry/index.jsp
30
Exhibit:
Hidden Depths
Exhibit Message
• The highest mountains and deepest trenches are found under the Earth's oceans.
Exhibit Description
A tabletop graphic shows a mountain (Mt Everest) and a trench (Yarlung Tsampo gorge) on
land and a mountain (Mauna Kea) and trench (Mariana trench) below the oceans.
By sliding the underwater mountain and gorge up to a reference line, users may be surprised
to find that these underwater features are higher and deeper respectively than the land
features.
Background Information
The oceans can claim Earth’s tallest mountain and deepest gorge.
When people are asked "What is the tallest mountain on Earth?" most would usually reply
"Mount Everest."
It is true that Mount Everest is the tallest mountain above sea level. However, if you included
ALL mountains on the Earth’s crust (above and below sea level and measured from Earth’s
inner core), then you could argue that there are other contenders for tallest mountain on
Earth.
When measuring mountains from base to peak, we find that:
• Mount Everest (Himalayas) is 8848 metres tall
• Mauna Kea (Hawaii) is 10 204 metres tall (with 4245 metres showing above sea level) and
• Mount Chimborazo (Ecuador) is about 6300 metres tall.
Mauna Kea is less well known as a tall mountain, because almost 60% of it is ‘hidden’ under
the ocean. Its remaining 40% peaks above sea level for 4245 metres. This makes it appear to
be about half the size of Mount Everest, which is 8848 metres.
Mountains near Earth’s equator may be considered to be taller because of the shape of Earth.
The equator gently bulges by an extra 21 000 metres due to the Earth’s spin. So, if you
measured from Earth’s inner core to a mountain peak, Mount Chimborazo near Earth’s
equator could claim to be the tallest on Earth.
When measured from base to peak, Mount Chimborazo in Ecuador is about 6300 metres tall.
Mount Chimborazo sits near Earth’s equator. So, it could be argued that if you measured the
height of Mount Chimborazo from Earth’s core to its peak, it ‘benefits’ an extra 21 000 metres
to become 27 300 metres.
Both Everest and Mauna Kea are positioned away from Earth’s equator and they do not
benefit from this extra 21 000 metre ‘boost’! If you measured their height from Earth’s inner
core to their peak, they would be roughly 14 800 metres and 16 200 metres respectively.
The Earth’s deepest gorge or trench is also found below sea level. Mariana Trench in the
Pacific Ocean was measured at 10 911 metres in 1995. Yarlung Tsampo gorge in the
Himalayan Mountains of China and Tibet is considered by most to be the deepest gorge on
land. The Yarlung Tsampo gorge is still being explored by scientists, but some measurements
show it is about 5900 metres at its deepest point.
More Information
Guinness World Records, Go to: Natural World<<Planet Earth
http://www.guinnessworldrecords.com
Altitude of the Highest Point on Earth
http://hypertextbook.com/facts/2001/ChristinaWong.shtml
31
Exhibit:
Food Pyramids
Exhibit Message
• Demonstrates how there are more animals at the ‘bottom’ of a food pyramid
compared to the ‘top’.
Exhibit Description
This four-tiered puzzle represents four levels of a food chain.
Users must:
• insert the eight corn pieces into the tabletop
• balance four mice shapes on the corn
• hang two snake pieces over the mice and
• balance the eagle on top.
Background Information
When an animal is at the ‘top of the food chain’, this means it
is rarely if ever eaten by another animal. Humans, eagles
and lions are examples of animals found at the top of a food
chain or food pyramid.
A food pyramid is similar to a food chain, except a pyramid
also shows the number or total biomass of plants and
animals. Biomass is the dry mass of the organisms in a food
pyramid. It measures how much the plants and animals in a
food chain would weigh if they were dried out, leaving only
biological material.
Eagles
Snakes
Mice
Plants
Eagles at the top of this food chain or food pyramid are
third order consumers. There are fewer eagles than
snakes.
Snakes in this food pyramid are second order
consumers. Animals that eat both plants and animals
are called omnivores, while animals that mostly eat
meat are called carnivores.
Mice are first order or primary consumers.
Animals (like mice) that eat plants are called
herbivores. They are usually found on this next level.
Plants (such as grain) are producers. Plants are found
at the very bottom of a food pyramid.
They’re called producers because they make their food
using the process of photosynthesis.
A predator gains chemical energy when it eats prey. This energy is used by the predator to
perform activities, such as fly, run or simply breathe. Some of this energy is also lost as body
heat and is not available to the predator in the next step of the pyramid. Because there is less
energy available to animals in the upper levels, there are fewer predators found in the upper
levels of a food pyramid.
32
New research by scientists called ecologists, shows that in meat-eating mammals (from
weasels to bears), every kilogram that they weigh needs 111 kilograms of prey to sustain the
predator.
More Information
Nature 25 March 2002 The rule of the game. Every kilogram of predator needs fixed amount
of prey.
http://www.nature.com/nsu/020318/020318-12.html
Recognising Bats in the Balance of Nature
http://www.batcon.org/disco/disco.html
Environmental Biology—Ecosystems
http://www.marietta.edu/%7Ebiol/102/ecosystem.html#Pyramids5
The Flow of Energy in Ecosystems
http://www.biologie.uni-hamburg.de/b-online/e54/54c.htm
Food Chains
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/FoodChains.
html
33
Exhibit:
Plants in Place
Exhibit Message
• Plants have evolved different features to cope with different temperatures, light levels
and water levels.
Exhibit Description
Once the tray is pushed in and clicked into place, users place tokens with plant photographs
into a matching pot, with a landscape picture.
Users can check if they correctly matched the plants to an environment by ‘unclicking’ the
tray. If plant tokens fall through, they were correct. Wrong answers are shown where plant
tokens stay in the pots.
The cactus belongs in the desert, the mangrove tree belongs in the mangrove swamp and the
fern belongs in the rainforest.
Background Information
Plants need sunlight, water, carbon dioxide, minerals and oxygen to survive. However, not all
environments can provide an ‘ideal’ level of these things, so over time plants evolve and
adapt to cope with their environmental conditions.
Desert plants tend to have waxy coatings to prevent water being lost from their leaves and to
reflect heat and sunlight. Some desert plants (particularly cacti) have fleshy, succulent tissue
to store water for the dry times. Plant cells that release water called stomates tend to be
sunken in desert plants. This protects stomates from drying winds and less water is lost from
the plant. Some desert plants also have hairy leaves to trap evaporated water and stop wind
from further drying the leaf.
Rainforest plants on the forest floor have plenty of water but struggle for sunlight. They have
large areas of foliage and often grow towards the Sun to absorb as much light as possible. To
keep the leaf fairly dry, many rainforest plants have a ‘drip tip’ that channels water quickly off
the leaf.
Mangroves live in an environment where salty water levels rise and fall around their roots
daily. If their roots get too waterlogged, plants can die. Mangrove trees grow prop roots that
peak above the loose, muddy soil to avoid suffocation. Mangrove plants also deal with the
salty environment by blocking salt from entering their roots or excreting salt through the base
of their leaves.
More Information
Australian National Botanic Gardens Rainforest Adaptations (open Adobe Acrobat on your
computer first, then use this link)
http://www.anbg.gov.au/education/pdfs/rainforest-teachers-2003.pdf
Missouri Botanic Gardens,
Desert Plants http://mbgnet.mobot.org/sets/desert/index.htm
Plant Adaptations (examples)
http://mbgnet.mobot.org/sets/rforest/index.htm
Micscape article – Plant adaptations
http://www.microscopyuk.
org.uk/mag/indexmag.html?http://www.microscopyuk.
org.uk/mag/articles/anne1.html
Physiological Adaptation of Mangrove plants
http://www-personal.usyd.edu.au/~nicksk/course/mangrove/phys.html
34
Mangrove Trees
http://www.naturia.per.sg/buloh/plants/mangrove_trees.htm
South Florida Museum of Natural History: Mangroves
http://www.flmnh.ufl.edu/fish/southflorida/mangrove/adaptations.html#
anaerobic
Cooperative Research Centres
Coastal Zone, Estuary and Waterway Management
http://www.coastal.crc.org.au/
Tropical Rainforest Ecology and Management
http://www.rainforest-crc.jcu.edu.au/
Pre-or post-visit classroom activities
Activity
Obtain a potted cactus and a potted fern or palm of similar size to the cactus. Place plastic
bags of equal size over same areas of leaf. Water each plant with the same amount of water
each day. How much water collects in the plastic bags over a few days? Does one plant seem
to release less water than the other?
Look at microscopic slides of cactus, casuarina leaves, geranium, elodea, etc. Count how
many stomata ‘holes’ are on same areas of leaf. These stomata holes allow water to
evaporate from the leaves.
Obtain three leaves of the same size and with equal length stems off a plant. Obtain three
small glasses (such as Vegemite glasses) and fill them to the three-quarter mark with water,
with a thin layer of cooking oil on top of the water (to stop evaporation of the water from the
glass). Rub some petroleum jelly (Vaseline) on the top side of one leaf, on the bottom side of
the second leaf and leave the third leaf uncovered. Place the stems into the glasses so they
are in the water. Watch the water levels over the next few days-which leaf drops the water
level the fastest? If a leaf lowers the water level more, what does this indicate about the
number of unblocked stomates it has? Do you think there are more stomates on the top or
bottom layer of the leaf?
35
Exhibit:
Living Cells
Exhibit Message
• All living things are made from cells, from single celled paramecium through to plants
and animals with billions of cells.
Exhibit Description
Enlarged microscope images of:
• a single paramecium cell,
• plant tissue and
• animal tissue
are printed on a tabletop disc, hidden from view by a cover.
Users look down through a viewing scope and turn the tabletop disc so each microscope
image comes into view.
Background Information
All living things are made up of cells. These organic building blocks come in many shapes
and sizes, but they all contain DNA.
Some tiny living things like bacteria and amoeba are single cells. Things like plants and
animals (including humans) are made up of dozens to billions of cells. Humans have an
estimated 50 million million cells!
Living things with many millions of cells have different cell-types. Humans have skin cells,
muscle cells, blood cells, even bone cells. When cells have a particular job to do, they are
called specialised cells.
Our red blood cells are specialised to carry oxygen. Our nerve cells are specialised to carry
electrical messages to and from our brain. Cells in plants are specialised for photosynthesis
or swelling up with water to keep the stem and leaves upright.
Although cells with different jobs can look very different, they have certain things in common.
All cells are like tiny, flexible balloons of cell membrane. They are filled with a clear gel called
cytoplasm. Swimming in the cytoplasm are:
• a bag of DNA (the nucleus) and
• microscopic parts that control the working of the cell and protein production. These
microscopic parts are called organelles.
Plants contain extra cell structures such as a cell wall (surrounding the cell membrane) and
chloroplasts that are involved in photosynthesis to make food for the plant.
Some scientists debate whether viruses are living things as well. Although viruses do not
contain cell membranes, they have a kind of protein coat that holds RNA, which is similar to
DNA.
More Information
Cell Biology
http://www.sciencenet.org.uk/database/bio/cells/cells.html
36
Exhibit:
Evolution
Exhibit Message
• Different animals living in similar environments have evolved similar limbs and body
shapes to move through their common environment. This is known as convergent
evolution.
Exhibit Description
A column of four-sided cubes has pictures
of different animals that move through the
air, water and underground. These
animals come from different classification
groups, but have evolved similar limbs and
body shapes to allow them to move in
their environment.
Users match up columns of animals
according to their classification group
(mammal, reptile, etc).
Even though animals in a matching
column belong to the same classification
group, they look very different and may
even look more like animals in other
classification groups. For example, a Wallace’s flying frog (amphibian) looks more like a flying
lizard (reptile) than a fellow amphibian rubber eel.
Background Information
Evolution is the gradual change in appearance and body chemistry of living things over
millions, even billions of years.
Convergent evolution occurs when different animals evolve and become alike. This occurs
particularly where the different animals live in similar environments and evolve adaptations
that improve their survival in that environment.
All plants and animals in a given species have subtle differences. Sometimes, a plant or
animal may be better at escaping predators or catching food or staying warm or cool. This
subtle difference may make it better able to survive in a changing environment.
The subtle differences are usually caused by the genes of the particular individual. Genes can
change slightly when sex cells such as egg and sperm are being made, or the genes mutate
due to ultraviolet light from the Sun, or chemicals in the environment.
Living things that are better adapted to their environment survive long enough to breed and
pass on their characteristics to offspring.
Over many millions of years, the plant or animal type can evolve to become a new species.
Sometimes, these new species share an environment with very different species and they
evolve to resemble each other physically (in their anatomy) or physiologically (in their body
chemistry).
For example, sharks (fish) and dolphins (mammals) have very different ancestry, but they
look very similar.
Two populations of fish in the Antarctic (southern hemisphere) and the Arctic (northern
hemisphere) have very different ancestors, but have independently evolved antifreeze
proteins to prevent their blood freezing. The genes that produce the antifreeze proteins in the
two fish populations are also quite different.
37
More Information
PBS Convergent Evolution
http://www.pbs.org/wgbh/evolution/library/01/4/l_014_01.html
PBS Evolution Glossary
http://www.pbs.org/wgbh/evolution/library/glossary/protein
Pre-or post-visit classroom activities
Background Research
Research similarities and differences between sharks and dolphins – how they move,
breathe, swim, their senses, etc.
What is meant by convergent evolution and divergent evolution?
38
Exhibit:
Landscape Journey
Exhibit Message
• As you travel around Australia, you pass through many different ecosystems. These
different landscapes differ in their temperature ranges, average rainfall and soil type.
Exhibit Description
A car knob is pushed to five different points on an Australian map.
At each point (A, B, C or D), a photograph of the landscape in that area of
Australia appears in a round window.
The landscapes displayed in the window include:
• coastal
• rainforest
• desert
• wetlands and
• alpine.
Background Information
Plants need certain soil nutrients, temperature ranges and rainfall levels to survive and grow.
Because Australia has such a wide range of environmental conditions, there is a wide range
of plant types. If you drive long distances, you can find very different-looking environments
from deserts to rainforests.
Far North Queensland has nutrient-rich soil and high rainfall, while central Australia has
lower-nutrient sandy soils and low rainfall. Plants have evolved over many millions of years to
cope with these different conditions.
Different plant species in turn create different ecosystems or bioregions.
Environment Australia has identified 85 different bioregions in Australia.
Examples of average rainfall and average temperature ranges for the points on the Earth
Quest exhibit Landscape Journey are listed below:
• Alpine areas -3 to 18°C, 900 millimetres rainfall
• Rainforest areas 15 to 30°C, 600 to 3200 millimetres rainfall
• Desert areas 15 to 30°C, 200 millimetres rainfall
• Coastal 12 to 24°C, 400 millimetres rainfall
• Wetland areas 18 to 36°C, 600 to 1200 millimetres rainfall
More Information
Environment Australia
Australia’s Biogeographical Regions, http://www.ea.gov.au/parks/nrs/ibra/index.html
Map of Australia’s Biogeographical Regions (needs Adobe Acrobat)
http://www.ea.gov.au/parks/nrs/ibra/pubs/ib5-cont-col-a4.pdf
Regional Descriptions
http://www.ea.gov.au/parks/nrs/ibra/version5-1/summary-report/summaryreport3.html#34
Bureau of Meteorology Climate Averages
http://www.bom.gov.au/climate/averages/
39
Sub-surface Zone
Exhibit:
Earthquake
Exhibit Message
• Earthquakes are caused by stresses of tectonic plates moving against each other.
Exhibit Description
A frame containing polyurethane pieces, covered by a polarising filter is held up to a light.
As the user pushes a lever to shift the polyurethane pieces past each other, stress points in
the polyurethane sheets can be seen, representing how tectonic plates push against each
other, creating stress points and earthquakes.
Background Information
Thousands of earthquakes occur around the world every year. Most earthquakes are minor
earth tremors, but some earthquakes are very strong and cause massive damage, particularly
if they occur near human settlements.
The Earth’s crust is broken into about twelve pieces called tectonic plates (a bit like a cracked
egg shell). The tectonic plates gradually move and drag against each other. This causes a lot
of stress or tension to build up in the rocks.
This stress is released when the rocks break and crush under pressure, causing the
vibrations we know as an earthquake.
These vibrations (called seismic waves) travel in all directions. They can travel at speeds up
to 14 kilometres/second. The strength of seismic waves determines how ‘violent’ an
earthquake will be.
Most earthquakes occur at tectonic plate boundaries. Some earthquakes (less than 10%)
occur in the centre of tectonic plates as well.
A fault is a break in the Earth's crust where large sections of rock have been crushed and
broken due to these stresses. Faults are divided into three main groups, depending on how
they move.
•
•
•
Normal faults occur where blocks are pulling apart (spreading zones).
Thrust faults occur where one block is compressed under an overlying block
(subduction zones).
Strike-slip faults occur where one block moves horizontally past another block.
The Earthquake exhibit in Earth Quest is similar to the San Andreas strike-slip fault. This fault
is found near California (United States f America) and is more than 1300 kilometres long and
up to 6 kilometres deep.
The San Andreas fault has the Pacific tectonic plate on the west side, and the North American
tectonic plate on the east side. The Pacific plate moves about 2.5 centimetres northwest each
year. This movement causes earthquakes along the fault, which has devastated cities such
as San Francisco in the past.
More Information
Geoscience Australia Earthquakes fact sheet
http://www.ga.gov.au/urban/factsheets/20010919_15.jsp
United States Geological Survey (USGS)
San Andreas Fault
http://pubs.usgs.gov/gip/earthq3/safaultgip.html
40
Earthquake Information for Kids
http://earthquake.usgs.gov/4kids/
Earthquake Information for the General Public
http://pubs.usgs.gov/gip/earthq1/
Pre-or post-visit classroom activities
Background Research
You are attempting the world record in building the tallest stack of playing cards. You have a
choice of building the stack in either San Francisco (United States) or Tokyo (Japan). Both of
these cities are prone to major and minor earth tremors, and you must choose one or the
other place. Which city would you choose to attempt your record? Are you best to try in a city
with larger, but infrequent earthquakes, or a city with regular, much smaller earthquakes?
http://quake.usgs.gov/research/seismology/wg02/
http://earthquake.usgs.gov/faq/#pred
41
Exhibit:
Volcanoes
Exhibit Message
• Some erupting volcanoes create mountains by building up lava deposits over many
years.
Exhibit Description
The tabletop exhibit shows a volcano in cross
section, with layers of previous lava flows and a
volcanic vent.
A lever is moved up and down to release waves of
lava (represented by rubber strips) through a
volcanic vent in cross section.
As each strip comes out from the vent, it spreads
out over the previous lava flow to gradually build
up a mountain.
Background Information
Volcanic eruptions are when extremely hot rock
escapes from inside the Earth and onto the Earth’s
surface.
While the hot, molten rock is inside the Earth, it is called magma and is stored in a magma
chamber. After magma has escaped through volcanic vents and on to the Earth’s surface, it is
called lava.
Volcanoes release magma or lava, because of:
• the buoyancy of magma (which tends to float),
• the pressure of gases dissolved in magma and
• magma squeezing into an already full magma chamber, pushing magma up and out through
a volcanic vent.
The way a volcano erupts depends on the thickness (viscosity) of its magma or lava.
Magma's viscosity is mostly controlled by its temperature, the elements it contains and its gas
content. Generally, magma that is hotter and contains less silica (silicon dioxide or SiO2) will
be more fluid and flow more easily.
Scientists are unsure how magma is made, but it may form when rock
in the upper mantle or lower crust sinks and melts (particularly in areas known as subduction
zones where one tectonic plate sinks under its neighbouring plate).
As layers of lava cool down, they set into rock. Lava contains more than ten different
minerals, so volcanic soils can be very fertile.
More Information
Geoscience Australia Volcanoes factsheet
http://www.ga.gov.au/urban/factsheets/20010827_9.jsp
USGS (United States Geological Survey)
http://vulcan.wr.usgs.gov/Outreach/AboutVolcanoes/
http://vulcan.wr.usgs.gov/Glossary/VolcanoTypes/volcano_types.html
http://pubs.usgs.gov/gip/volc/text.html
http://interactive2.usgs.gov/learningweb/explorer/topic_hazards_volcano
es.asp
42
Scientific American, Ask the Experts,
What causes a volcano to erupt and how do scientists predict eruptions? 29 November 1999,
http://www.sciam.com/print_version.cfm?articleID=0001FC71-C354-1C719EB7809EC588F2D7
How do volcanoes affect world climate? 15 April 2002
http://www.sciam.com/print_version.cfm?articleID=000D4121-91C5-1CD1B4A8809EC588EEDF
Savage Earth Volcanoes
http://www.thirteen.org/savageearth/volcanoes/index.html
Physiochemical Controls on Eruption Style
http://www.geology.sdsu.edu/how_volcanoes_work/
43
Exhibit:
Core Samples
Exhibit Message
• Core samples allow scientists to study Earth’s history and natural resources.
Exhibit Description
Three landscapes (ice, ocean sea bed and continent) are shown on the exhibit tabletop.
Users can pull up a column representing a geological core sample. Each column contains a
photographic image of real core samples taken in Antarctica, the seabed off Victoria, Australia
and a road cutting near Canberra, Australia.
Background Information
Scientists can learn a lot from core samples, which are long plugs of earth drilled from the
ground.
Core samples can reveal:
• what the climate was like thousands of years ago
• levels of gases such as carbon dioxide over time
• natural resources such as gas and oil
• when major events occurred on Earth, such as meteor showers
• ancient fossils or DNA showing how life has evolved or
• how Earth’s landscape has changed with oceans forming and receding.
Core samples are taken by drilling many metres deep into the ground and removing a plug of
earth. Samples can be taken on the ocean floor, on dry land and in icy regions such as
Antarctica.
The three core samples in the Earth Quest exhibit Core Samples were taken from Antarctica,
the ocean floor (near Victoria, Australia) and Canberra (Australia).
1. The Antarctica sample shows layers of ice and sediment, with a microscopic cross section
showing bubbles from the core sample.
2. The ocean floor on the East Tasman Plateau, known as the K/T boundary. This sample
shows a layer created by a meteorite that is thought to have wiped out the dinosaurs tens of
thousands of years ago.
3. The land sample from an area near Canberra shows layers of sediment laid down over
thousands of years.
Education Materials (continued
More Information
PBS Stories in the Ice http://www.pbs.org/wgbh/nova/warnings/stories/
Antarctic CRC & Australian Antarctic Division, Dr Tas Van Ommen,
http://www.antcrc.utas.edu.au/antcrc/
Scientific American News 18 September 2000, Himalayan Ice Cores
http://www.sciam.com/print_version.cfm?articleID=000D4E78-7113-1C61B882809EC588ED9F
Scientific American News 18 September 2000, Moving Impurities Muddy Some Ice Core
Analyses
http://www.sciam.com/print_version.cfm?articleID=000416C3-EC041C5EB882809EC588ED9F
Scientific American News 18 April 2003, Sediment Cores Yield Oldest DNA Yet Discovered
http://www.sciam.com/print_version.cfm?articleID=000DFC3D-15461E9FA9B3809EC588EEDF
44
Exhibit:
Surface to Core
Exhibit Message
• Displaying Earth’s sub-surface layers from the inner core to the crust.
Exhibit Description
A metal ball hemisphere sits on the
tabletop representing Earth’s inner core.
Separate acrylic arches representing
layers of Earth’s sub-surface are layered
over the globe.
Users can then pull each disc across and
look down to see individual layers, or the
whole of Earth’s sub-surface, including:
• the outer core
• the lower mantle mantle and
• the upper mantle/crust.
As each arch is flipped down or up, they
reveal approximate temperatures and
layer thickness for that particular layer.
Background Information
While humans live on the Earth’s surface, we tend to forget the thousands of kilometres of
rock and moving magma beneath the surface. In the last one hundred years or so, scientists
have discovered that the Earth beneath our feet may be divided into layers. These layers are
probably an inner core, an outer core, a lower mantle, an upper mantle and crust.
Earth formed several billion years ago when clouds of dust and gas collided and condensed
to form the Solar System. Elements and minerals found on Earth (particularly iron and iron
alloys with nickel) can be found in similar proportions on the Sun, meteorites and other
planets.
Inner Core—about 1200 kilometres across, up to 6000 °C
Gravity pulled dust and small meteorites together to form Earth’s inner core. These collisions
generated extreme heat which melted iron in the meteorites. The liquid iron sank to form
Earth’s metallic inner core. The inner core probably also contains a little sulfur and oxygen.
The inner core is probably solidifying from the inside-out because of the extreme pressure of
the overlying layers. It may have started solidifying around 2000 million years ago.
The inner core is now believed to be about 3700 to 6000 °C (the same as the Sun’s surface).
It has pressures around 300 million times higher than at the Earth’s surface.
Outer Core—about 2300 kilometres thick, 3700 °C
The outer core is thought to be made of liquid iron. This is where the
Earth's magnetic field is generated. Every few hundred thousand years, the magnetic field
reverses, so Earth’s magnetic poles (north and south)shift. Scientists know this by studying
the magnetism preserved in rocks.
Lavas and sedimentary rocks containing iron minerals lock in the direction of the magnetic
field when they solidify.
45
Lower Mantle—about 2200 kilometres thick
The transition zone between the lower mantle and the outer core can reach pressures more
than a million times higher than at the surface, and an increase in density greater than the
density difference between air and soil.
The lower mantle is thought to contain silicon dioxide and magnesium oxide. The temperature
of the lower mantle (near the core) is much higher than the upper mantle (near the crust).
Education Materials (continued
While scientists originally thought that the lower mantle was rock solid, they now think that it
contains vast blobs of gooey semi-molten rock up to 40 kilometres thick and as wide many
continents.
Upper Mantle—720 kilometres thick
When fluids warm up and cool down, they flow around in a cycle called a convection current.
Molten rock (magma) close to the outer core is hotter and less dense than magma close to
the Earth’s surface, which is cooler and more dense. When dense magma sinks, it pushes the
hotter magma up towards the Earth’s surface. Magma is mostly heated by the core and
possibly by radioactive elements such as uranium.
Also, molten rock is more buoyant than solid rock. But maybe magma’s heavy iron content
weighs it down, so it stays near the core-mantle interface.
Scientists are unsure whether convection currents only occur in the upper mantle or occur all
the way down to where the core and mantle meet. Recent research suggests that the latter is
true.
Crust—up to 100 kilometres thick
The Earth’s crust that we stand upon ‘floats’ upon the upper mantle.
The crust is broken up into twelve major tectonic plates.
The continents are made of granite or light silicate minerals containing silicon, oxygen,
aluminium and calcium. This makes the continents less dense than the basaltic oceanic crust
or the mantle.
More Information
How did the earth come to have a molten iron core?
http://www.physlink.com/Education/AskExperts/ae604.cfm
Scientific American, Ask the Experts, 6 October 1997, Why is the earth's core so hot? And
how do scientists measure its temperature?
http://www.sciam.com/print_version.cfm?articleID=000B2C71-BCF0-1C719EB7809EC588F2D7
What causes the periodic reversals of the earth's magnetic field? Have there been any
successful attempts to model the phenomenon? 21 October 1999
http://www.sciam.com/print_version.cfm?articleID=0002B1A2-BD8F-1C719EB7809EC588F2D7
46
Exhibit:
Tectonic Plates
Exhibit Message
• The Earth's crust consists of tectonic plates, which fit together like a puzzle (most
‘joins’ are on the ocean floor).
Exhibit Description
A map of the world has been cut up into the major tectonic plates, so the pieces can be
placed together like a jigsaw puzzle.
Once complete, users can check the graphic panel to see the names of the tectonic plates
and see where most earthquakes occur (on the boundary lines).
Background Information
The Earth’s crust is broken into about twelve major pieces called tectonic plates (a bit like a
cracked egg shell).
The tectonic plates join together like a three-dimensional jigsaw puzzle, with most ‘joins’
between plates fitting together on the ocean floor.
Tectonic plates are usually made of two parts:
1. oceanic crust (which tends to be more dense) and
2. continental crust (which tends to be less dense).
Tectonic plates can be 5 to 100 kilometres thick. Continents (such as Africa) are simply very
thick sections of tectonic plate—they are not separate to the tectonic plates.
Tectonic plates sit on extremely hot rock, which heats up and cools down to create circulating
convection currents. These currents are strong enough to gradually shift the plates around
over millions of years (formerly known as continental drift). The tectonic plates shift 2.5 to 7
centimetres per year or 25 to 50 kilometres over one million years.
Tectonic plates next to each other can move in many different ways:
• each plate may move against each other in opposite directions or in the same direction
(transform faults such as the San Andreas fault in the United States)
• one plate may sink beneath a neighbouring plate (subduction zones such as the Andes
mountains)
• both plates may buckle up where they meet (such as the Himalayan mountains) and
• both plates can move away from each other (spreading zones such as Rift Valley, Africa).
More Information
United States Geological Survey (USGS)
Plate Tectonics http://geology.er.usgs.gov/eastern/tectonic.html
The Tech Museum Plate Tectonics
http://www.thetech.org/exhibits_events/online/quakes/plates/divergent.
Html
Pre-or post-visit classroom activities
Activity
Cut up a globe of the Earth into major tectonic plate pieces (check second hand stores for
cheap, damaged globes). Try and piece the globe back together as a three dimensional
globe. Cut up 2D map of tectonic plates. See if you can put the globe back together.
Map of tectonic plates http://geology.about.com/library/graphics/crustalplates.gif
47
Exhibit:
Fossil Finder
Exhibit Message
• Certain fossils can help scientists date layers of earth. These fossils lived for a certain
period of time and are called index fossils.
Exhibit Description
A chest of four drawers represents an archaeological dig (with pick and realscale ruler graphic
on top of the chest). Each drawer must be pulled out to view a different fossil. Each fossil is
printed on the graphic panel with its age, so users can work out how old that layer of earth is
likely to be.
Background Information
When living things die, they usually rot away and leave no trace. Sometimes, rotting tissue
gets replaced with minerals, so preserved bone or a cast of that living thing is left behind.
These are called fossils.
Fossils may be formed from tiny pollen through to massive dinosaurs.
When living things die, they may be quickly buried under sediment—particularly if they’re lying
at the bottom of a lake or river and are being covered by layers of mud or sand.
With time, this muddy sediment hardens and becomes sedimentary rock.
The living tissue rots away to leave an impression in the rock, particularly parts such as bone
and shell. Living things that are mostly soft tissue (such as flowers or worms) are very rarely
fossilised.
The chance of a dead organism becoming fossilised is extremely small.
Plants and animals living in dry areas or riverlands have more chance of being fossilised than
organisms living in wet, tropical environments, where they are decay more quickly.
Scientists research fossils to work out the age of a layer of rock and how living things have
evolved. Over many millions of years, younger fossils are laid above layers of rock containing
older fossils. This creates a kind of timeline, showing what plants and animals lived where
during different periods of time.
Fossils of plants and animals that are known to have lived for short periods of time are called
index fossils. When these index fossils are found in a layer of rock, they are used to judge
how old the layer is. Index fossils are usually fairly common and widely distributed
(geographically).
The index fossils used in the Earth Quest exhibit are nanofossils (they can usually only be
seen using a microscope). Original photographs of the microfossils were provided by
Geoscience Australia and include: Foraminiferida (6-23 million years ago); Dinoflagellata
(149-155 mya); Brachiopod (458-460 mya); Brachiopod (477-479 mya); Trilobite (502-503
mya).
More Information
Scientific American, Ask the Experts, What are the odds of a dead dinosaur being fossilized?
http://www.sciam.com/print_version.cfm?articleID=000319F6-D131-1D7790FB809EC5880000
United States Geological Survey (USGS)
Index Fossils http://pubs.usgs.gov/gip/geotime/fossils.html
Fossils, Rocks and Timehttp://pubs.usgs.gov/gip/fossils/fossils-rocks.html
A Basic Introduction to Fossils http://www.adders.org/fossils/intro2.html
48
Hawaii University Index Fossils http://lilt.ics.hawaii.edu/belvedere/
materials/Mass-Extinctions/Indfoss.htm
New Scientist Last Word, If human beings were wiped out by some sort of catastrophe, would
any evidence of our existence be discovered 65 million years later?
http://www.newscientist.com/lastword/article.jsp?id=lw170
Pre-or post-visit classroom activities
Activity
Place a small seashell in a ball of plasticine, allowing a small access hole to run through the
shell from the top and out the bottom of the plasticine. You can make the hole using a
wooden skewer. Drop a little vinegar into a hole each day to dissolve the shell and allow
gases from the chemical reaction of the shell breakdown to escape. This will be messy, so do
it over a sink! Then, block one of the holes and pour a little plaster of Paris into the plasticine
to create a cast from the mould left by part or all of the shell. Allow the plaster of Paris to set
for a few days, then remove the plasticine to see your ‘fossil’.
Background Research
How fossils form http://www.minerals.nsw.gov.au/minfacts/61.htm
Australian Museum information about fossils
http://www.austmus.gov.au/webinabox/fossils/resources/information.htm
49
Exhibit:
How Deep?
Exhibit Message
• How deep humans have ventured into the Earth compared to other living things.
Exhibit Description
A scaled down model, demonstrating the maximum depths that a mineshaft, penguin, whale
and submarine have reached.
These objects are shown graphically on the exhibit tabletop, with markers at the same starting
point (sea level or ground level). By pushing a lever down, the markers sink to the depths that
each animal or thing has reached (from 483 metres to 10 kilometres).
Information on the graphic panel also describes how shallow these depths are compared to
the thickness of Earth’s crust and lists other recorded depths not shown on the interactive
exhibit (due to scale).
Background Information
Humans, plants and animals have only scratched the Earth’s surface. The Earth’s crust is up
to 100 kilometres thick, and it is more than 6000 kilometres to Earth’s centre from the surface.
The deepest humans have ever dug is a Russian bore hole, which reached 12 kilometres
deep. Humans have not gone down this bore hole.
The deepest dive by a woman in water without using SCUBA equipment (free diving) was by
a French woman who dived 125 metres.
Deepest mine shaft
Deepest dive by a bird
Deepest submarine
Deepest dive by a mammal
2.7 kilometres
(South Africa, gold mine)
483 metres
(Antarctica, emperor penguin)
6.5 kilometres
2 kilometres
(Caribbean, sperm whale)
More Information
Guinness World Records http://www.guinnessworldrecords.com/
Go to:
Natural World<<Planet Earth
Natural World<<Animal Extremes
Natural World<<Extraordinary Animals
Amazing Feats<<Courage and Endurance<<Female Deep Dive
World’s Deepest Shaft for Gold Mine
http://www.valve-world.net/projects/news_fullstory.asp?NewsID=2096
Pre-or post-visit classroom activities
Activity
Students use a globe of the Earth to find out where they should start digging in the northern
hemisphere, so they came out on a continent in the southern hemisphere. If you start digging
in the northern hemisphere, are you more likely to come out in an ocean or through a
continent in the southern hemisphere?
50
Exhibit:
Exploring Earth
Exhibit Message
How do scientists know what is located within the centre of the Earth, having never been
deeper than the crust?
Exhibit Description
Three metal globes are filled with a:
• solid (sand)
• liquid (water) and
• gas (air).
When struck with the beater, each globe sounds
and ‘feels’ different. After hitting the globes and
trying to guess their contents, users can turn the
frame upside down, which reveals a small window
in the base of each globe so they can see the
globe’s contents.
Background Information
It can be difficult to explore areas you cannot visit,
such as outer space and deep underground.
Scientists mostly explore the layers of the Earth by
studying earthquake vibrations. These vibrations
are called seismic waves.
Equipment that measures the strength of seismic
waves (seismometers) are set up all around the
world, but scientists most interested in exploring
the depths set up seismometers in areas where strong earthquakes are most likely to occur.
They are arranged in an arc 105° and 142° away from the earthquake's most likely epicentre.
Sometimes seismometers are set up in areas where nuclear testing takes place as well!
Seismic waves can only really be measured on Earth’s surface.
As the waves travel underground, they slow down or speed up.
From this, scientists can work out whether the waves passed through dense rock, soft molten
rock or even rock containing gas or oil. This is because these rock types have different
densities.
There are different types of seismic waves. The fastest waves can travel up to14
kilometres/second. At this speed, it would take only 20 minutes or so for these waves to travel
through the centre of the Earth and reach the other side (about 12 000 kilometres). P waves
are pressure or compression waves. S waves are shear waves, which do not travel through
Earth’s core but may be converted to P waves when they hit the core.
Some waves travel down and hit an area called the diffractive phase (near the outer core and
mantle boundary). These waves get bogged down then are reflected and race back to the
surface. This bottom 100 kilometres of the mantle slows down seismic waves by a few per
cent.
Scientists also explore the layers of the Earth by analysing data on how the Earth rotates, its
inertia, magnetic fields, and by performing laboratory experiments on melting and alloying
iron.
More Information
Scientific American, Ask the Experts, 6 October 1997, Why is the earth's core so hot? And
how do scientists measure its temperature?
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http://www.sciam.com/print_version.cfm?articleID=000B2C71-BCF0-1C719EB7809EC588F2D7
How do scientists know what is in the core of the Earth?
http://www.soest.hawaii.edu/GG/ASK/earths_core.html
United States Geological Survey, Inside the Earth
http://pubs.usgs.gov/publications/text/inside.html
The Interior of the Earth http://pubs.usgs.gov/gip/interior/
Earth’s Interior
http://www.seismo.unr.edu/ftp/pub/louie/class/100/interior.html
How do we know what the inside of the Earth is like?
http://www.madsci.org/posts/archives/oct98/909513628.Es.r.html
New Scientist Vol 160 issue 2156 17 October 1998, page 38 Deep Secrets
Pre-or post-visit classroom activities
Activity
Fill four aluminium soft drink cans with sand, liquid soap, water or air. As you hit each can
‘feel’ for any difference in the vibrations on the other side of the can. Is it easier to feel the
vibrations through some fillings more than others? Do you think the Earth’s layers are liquid or
solid?
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Exhibit:
Dig a Hole
Exhibit Message
Explore where you would come out if you dug a hole through the centre of the Earth from
different starting points.
Exhibit Description
A globe of the Earth has pointers attached to the frame holding
the globe on the tabletop. After moving one pointer to a
chosen point, visitors can check the opposite pointer on the
other side of the globe to gauge the point they would dig
through to on the other side of the Earth.
Users may be surprised to discover that they are most likely to
emerge in the ocean if digging through.
Background Information
It would be impossible to dig a tunnel through to the other side
of the world, but it’s fun to pretend!
If you attempted to dig a hole to the other side of the Earth,
you would be digging through:
• more than 12 000 kilometres of solid rock and molten magma
• rock reaching temperatures up to 6000 ºC and
• extreme pressures up to 300 million times greater than the
pressures we experience on the surface of the Earth!
Also, the Earth is not a perfect sphere. It is slightly flattened at
the poles, and bulges a little at the equator due to the Earth’s
spin. So technically, if you dig a tunnel through to the other side of the globe, you would not
come out at the place shown on a desk globe which is an almost perfect sphere.
If you did somehow manage to dig a hole to the other side of the Earth, would you fall
through? Again, theoretically no! The Earth continues to spin as you fall, gravity changes as
you fall to the Earth’s centre and friction would slow you down. If you ignored all of these
factors, scientists think it would take about 42 minutes to fall through the tunnel.
More Information
Scientific American Ask the Experts 21 April 2003 Would you fall all the way through a
theoretical hole in the earth?
Scientific American April 21,
http://www.sciam.com/print_version.cfm?articleID=0008230B-DE971E9EA9B3809EC588EEDF
New Scientist The Last Word If you could journey to the centre of the Earth, what would be
the sensation of gravity at various points on the way down, and at the centre?
http://www.newscientist.com/lastword/article.jsp?id=lw388
Did you ever dream of digging a hole so deep it came out the other side
of the Earth?
http://amos.indiana.edu/library/scripts/hole.html
If I dig a hole through the earth from here, where do I wind up?
http://www.jessamyn.com/dig/
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Pre-or post-visit classroom activities
Activity
Imagine it takes on average half an hour (30 minutes) to dig a hole 20 centimetres deep. If
you need to dig 6 000 kilometres to the centre of the Earth, how long would it take if you dig at
this rate?
You may even like to experiment and see the average time taken for five students each to dig
a 5 cm hole in the playground, using a ruler to measure depth, and setting the width at a
certain number of centimetres. The class can then calculate how long it would take an
average digger, the slowest digger and the fastest digger to reach the centre of the Earth.
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