Learning on the Edge
Spring 2012 Issue
Delta News
Fun Facts
On the Houston Toad - This native toad was the first
amphibian to be placed on the Endangered Species
List and lives only in Texas. Unfortunately most of the
remaining population lives where the Bastrop fires occurred last September. As spring begins scientists are
surveying heavily to determine if the toad remains in
significant numbers.
On Rainbows - This phenomena of the atmosphere appears during or immediately following local showers,
when the sun is shining and the air contains raindrops.
A rainbow can best be seen with polarized sunglasses.
We cannot follow the arc of a rainbow down below the
horizon, because we cannot see those droplets in the
air below the horizon. But the higher we are above the
ground, the more of the rainbow circle we would see.
That is why, from an airplane in flight, a rainbow will
appear as a complete circle with the shadow of the airplane in the center.
On Bats - Bats worldwide are in decline. There are over
1,200 known species of bats which make up 25% of
all mammal species.
The smallest bat is
the bumblebee bat
from Thailand and
the largest bats are
giant flying foxes,
which have a wingspan of 6 feet. The
Mexican free-tailed
bats in Bracken Cave
can eat 250 tons of
insects in a single
night!
Upcoming Dates
February 27 - 5th Grade Science “In the Bag” workshop- ESC Region 2
http://www.esc2.net/
February 28 - Smoky Bear’s birthday
February 29 - Leap Day
March 8 - Middle School Science, No Lab,
No Problem workshop- ESC Region 2
http://www.esc2.net/
March 11 - Johnny Appleseed Day
March 11 - 16 - Intracoastal Waterway
Wetlands Expedition- Gulf of Mexico
Foundation www.gulfmex.org
March 14 - Pi Day/Albert Einstein’s birthday
March 17 - Project WET Workshop- Texas State
Aquarium www.texasstateaquarium.org
March 22 - World Water Day
March 24 - 25 - Leopold Education Project
Educator/Facilitator Training Workshop Welder Wildlife Foundation
www.welderwildlife.org
April 3 - Find a Rainbow Day
April 17- Bat Appreciation Day
April 21 - Earth Day - Bay Day at Heritage Park
April 22- Earth Day
April 26- Audubon
Day
Energy & Society Workshop Summary
On January 13th we had seven teachers join us for Project Learning Tree’s Energy
& Society Workshop, led by Auburn Buehring of the Texas State Aquarium. The
teachers participated in lots of hands-on activities, from taping energy symbols on
objects that use or produce energy, to learning dances to help understand energy
principles and playing a heated Jeopardy game. We hope to see you at one of our
future workshops.
Build Your Own Barometer
Background
Air exerts pressure on Earth’s surface. In fact, it exerts pressure in all directions—down, up and
sideways—at the same time! At sea level, air weighs 14.7 pounds per square inch. That means
that a desktop area 2 inches by 2 inches has almost 59 pounds of air sitting over it. Standard
copy paper (8.5 x 11 inches) has close to 1,375 pounds of air holding it down AND up at the
same time.
Materials
•
Empty coffee can
•
large, heavy-duty latex balloon
•
heavy rubber band
•
scissors
•
coffee stirrer
•
3x5 card
•
duct tape
•
white glue
Precautions
• It is important you build these weather instruments while under the direct supervision of an
adult who has knowledge of safety precautions related to all materials listed.
• Care must be taken when working with power tools, fire, heat-generating electrical devices, hand tools, sharp objects and other tools. Do not use these devices unless there is an adult present to supervise.
• Cutting plastic soda bottles can leave sharp and pointed edges. Be sure to file or sand any cut edges immediately
after cutting.
• An adult must install devices that require a ladder to access installation areas.
• Do not attempt to access your weather station during storms.
Procedure
Read all Precautions before beginning this activity.
1. Smoothly tape the rim of the coffee can so the metal edge is completely hidden but remains open. Be sure the
tape smoothly extends down the side of the can an inch or more. To effectively do this, tape around upper side of the
can leaving at least 1/2 inch of tape sticking up over the rim. Use scissors to make 8 to 10 cuts in the protruding tape
straight down to the can rim. Fold the tape down and smoothly stick it to the inside of the can.
2. Cut the filler hole off the balloon and discard. Stretch the balloon tightly over the taped edge and secure it with a
rubber band. Make the rubber band as tight as you can.
3. Put a drop of white glue in the center of the stretched balloon. Put the coffee stirrer on the glue and position it so
that it protrudes about 1/2 inch over the edge of the can.
4. Tape the 3x5 card on the side of the can so that it extends over the top and is close but not touching the coffee stirrer.
5. Mark the card at the tip of the stirrer. It isn’t necessary to put numbers there.
6. Write the current barometric pressure in a journal. Determine if the pressure is high, low or “somewhere in be
tween.” This will be your baseline pressure. Be sure to note the position of the mark on the 3x5 card corresponding to
the pressure.
7. Repeat step 6 through several cycles of weather. Be sure you have several highs and lows marked on your card and
that you have entered all information in your journal.
When you become accustomed to the way your barometer works, you will have a tool with which to predict the
weather. Determine how the barometric pressure correlates to present weather.
How Tides Work
Grade Level: Grades 3-5
Subjects: Science, Math
Materials:
Per student: Science Journal, Pencil
Per Group: Large Ziploc bag (place all supplies in bag), Floral wire, Large piece of cardboard, Pencil, Drawing compass,
Scissors, One 8-inch and one 24-inch piece of string, 3 Push pins, Ruler, Tape, Dime, Quarter
Vocabulary: Tides, Gravity, Neap Tide, Spring Tide
Objectives
The student will learn that tides are caused by the gravitational pulls of the moon and sun on the earth, as well as
centrifugal force on the earth’s side opposite the moon.
Background Information
The word “tides” is a generic term used to
define the alternating rise and fall in sea
level with respect to the land, produced
by the gravitational attraction of the moon
and the sun. To a much smaller extent,
tides also occur in large lakes, the atmosphere, and within the solid crust of the
earth, acted upon by these same gravitational forces of the moon and sun.
What are Lunar Tides
Tides are created because the Earth and
the moon are attracted to each other, just
like magnets are attracted to each other.
The moon tries to pull at anything on the
Earth to bring it closer. But, the Earth is
able to hold onto everything except the
water. Since the water is always moving,
the Earth cannot hold onto it, and the moon is able to pull at it. Each day, there are two high tides and two low tides.
The ocean is constantly moving from high tide to low tide, and then back to high tide. There is about 12 hours and 25
minutes between the two high tides.
Tides are the periodic rise and falling of large bodies of water. Winds and currents move the surface water causing
waves. The gravitational attraction of the moon causes the oceans to bulge out in the direction of the moon. Another
bulge occurs on the opposite side, since the Earth is also being pulled toward the moon (and away from the water on
the far side). Ocean levels fluctuate daily as the sun, moon and earth interact. As the moon travels around the earth
and as they, together, travel around the sun, the combined gravitational forces cause the world’s oceans to rise and
fall. Since the earth is rotating while this is happening, two tides occur each day.
What are the different types of Tides?
When the sun and moon are aligned, there are exceptionally strong gravitational forces, causing very high and very
low tides which are called spring tides, though they have nothing to do with the season. When the sun and moon are
not aligned, the gravitational forces cancel each other out, and the tides are not as dramatically high and low. These
are called neap tides.
Spring Tides
When the moon is full or new, the gravitational pull of the moon and sun are combined. At these times, the high tides
are very high and the low tides are very low. This is known as a spring high tide. Spring tides are especially strong tides
(they do not have anything to do with the season Spring). They occur when the Earth, the Sun, and the Moon are in a
line. The gravitational forces of the Moon and the Sun both contribute to the tides. Spring tides occur during the full
moon and the new moon.
Neap Tides
During the moon’s quarter phases the sun and moon work at right angles, causing the bulges to cancel each other.
The result is a smaller difference between high and low tides and is known as a neap tide. Neap tides are especially
weak tides. They occur when the gravitational forces of the Moon and the Sun are perpendicular to one another (with
respect to the Earth). Neap tides occur during quarter moons.
Introduction
Tell students that today they are going to be exploring tides and how they work. Have either a class discussion or have
students write in their journal about their prior knowledge of tides.
Some questions:
1. What is a memorable experience you’ve had with tides?
2. What do you know about how tides work?
3. What comes to mind when you hear the words “high tide” or “low tide”?
Investigate
Students will be making a sun-moon-earth tide model. You can
either: demonstrate and have students write the steps in their journal, or have groups work through the procedure as you do it.
1. Use the cardboard as your base. In the upper center of the
cardboard, using a compass, draw a 4-inch diameter circle. Write
“Earth” in the middle of it.
2. Place one pushpin about ½ inch above the middle circle. Place the other two pins ½ inch to the right and left of the
circle.
3. Make the wire into a circle with an approximately 5-inch diameter. Place it over the pins (and around the drawn
earth).
4. Loosely tie the center of the 8-inch string (so that it can slide) around the wire so that it is opposite of the top pushpin.
5. Measure and cut both ends of the string so that the pieces of string on the wire are 3 inches long.
6. Tie the center of the 24-inch string around the wire.
7. Measure and cut both ends of the string so that one side is 3 inches long and the other piece is 10 inches long.
8. Tape one of the original 8 inch string pieces to the center of the Earth circle. Tape a dime to the other end of the
string.
9. Tape the 3-inch piece of the 24 inch string to the center of the Earth circle. Tape a quarter to the 10 inch side of this
string.
10. Explain to the students that the dime represents the moon, the quarter represents the sun, and the wire represents the water on Earth.
11. Slide the dime to the top of the circle (behind the top pushpin), and the quarter to the bottom of the circle (opposite the top pushpin). Pull on each coin with equal force. Ask the students to notice what is happening with the water
(wire). It should be bulging a lot at the top and bottom of the Earth.
The students should now make their own model in groups. Hand out a bag of supplies to each group. Move around
the room and make sure students are on task and know what to do.
When students have finished building their model they should be encouraged to try pulling the moon around the
earth in different arrangements and notice what happens to the water. The sun should always remain in the same
place, at the bottom of the earth, opposite the top pushpin.
After “playing” with the models for a few minutes, have students draw diagrams in their journals of what the model
looks like when the sun and moon are opposite of each other (full moon), when the sun and moon are at a 90 degree
angle from each other (quarter moon), and when the sun and the moon are aligned on the same side (new moon).
Remind students to label their diagrams.
Reflection and Sharing
Ask students to share their observations in a class discussion. Ask them what conclusions they can draw about tides
and their relationship to the moon and sun from their observations (highest high and lowest low occur at new moon,
there is little variation between the tides during a quarter moon).
Explain to the class that a neap tide is when the sun and moon are at 90 degree angles from each other. Neap is a
Saxon word meaning ‘scare or lacking.’ So when this occurs there is little variation between high and low tides.
The spring tide is when the sun, earth and moon are all aligned (new and full moons). Spring is a Saxon word that
means ‘to swell’. So when this occurs there are the highest high tides and the lowest low tides.
*Background information is from Moon Tides: How the Moon Affects Ocean Tides http://home.hiwaay.net/~krcool/
Astro/moon/moontides/
** Activity is from Padilla Bay NERR
Learning on The Edge News
The dates for this summer’s Learning on the Edge workshops have been posted.
This workshop is a weeklong workshop that includes materials from CBBEP as well
as various partners. We offer one week for elementary teachers, one for secondary teachers and a week for Alumni or teachers who have previously attended the
Learning on the Edge workshop and want to learn more.
The registration forms are on our website at: http://nuecesdeltapreserve.org/
workshops.html. The final date to register for these workshops is May 31. Remember that we cap each workshop at 20 participants.
This summer’s dates are:
Elementary - June 11- 15
Secondary - June 18-22
Alumni - June 25-29
Other Workshop Opportunities:
The Gulf of Mexico Foundation is also offering teacher workshops. They have two different workshops occurring this
summer and one over Spring Break. The Intracoastal Waterway Wetland Expedition (IWWE) is a weeklong trip from
Freeport, TX to Louisiana and back and explores coastal habitats along the way. This workshop is occurring during
Spring Break from March 11-16 and twice during the summer June 10-15 and June 17-22. Registration for the summer workshops is due by April 20.
The Foundation is also offering a workshop titled: Down Under, Out Yonder which is a partnership with the Flower
Garden Banks Marine Sanctuary. This program allows teachers a chance to visit and scuba dive at the Flower Gardens. Teachers must already be SCUBA certified to participate. The workshop takes place July 6-11 and the application deadline is February 27.
For more information on either of these workshops please contact Suraida Nañez-James at [email protected] or
(361)882-3939.
1. Yellowstone National Park was established March 1, 1872. Describe your favorite park or natural area. Do
you think we should preserve it the way we’ve preserved Yellowstone?
Jounraling Topics
2. March 18 marks the anniversary of the first space walk. Imagine that you were on this walk. Describe how
you think Earth would look from space. What would you look for? What would you recognize? What would
you NOT want to be able to see from space?
3. Catch an insect or other arthropod in your school yard. Write a paragraph about what you think about this
critter (facts you may know, things you’ve heard, how you feel when you look
at it {scared, it’s cute, want to squish it, etc.}). After finishing your paragraph
try to identify your critter and research 5 facts about it using at least two different sources. Then write a paragraph describing what you now know about
this critter. Did you change anything about how you felt?
4. Collect a few twigs from the surrounding area and bring them into the classroom. Have students form groups and give each group their own twig. Students should record in their journal: a description of the twig including size
(use a ruler), texture, color, shape and any other relevant information. See if
students can determine what kind of plant their twig came from.
5. Have students bring in a rock they’ve found outside. Students should give
their rock eyes, name it and decorate it as they choose. Then have students
write a story explaining how this rock came to the Coastal Bend. (Remember
that we are in a low lying area with very few natural large rocks. This is a lesson in erosion or in relocation of building materials. You could also bring up
discussion of the jetties and where that rock comes from).
For more information
or classroom
presentations contact:
Lari Jo Johnston
or Sara Bounds
Coastal Bend Bays
& Estuaries Program
361 - 673-6830
[email protected]