Investigative Projects for Earth Science Today
Russ Colson
Following are eight example projects that you can do. Some of these project descriptions provide substantial details of experiments actually done with elementary or middle school kids, while others provide only a general outline from which an investigation can be developed. Regardless of which project you choose, I would hope that all of you use your own thinking and creativity to modify or improve upon your project. Certainly, you will at the very least need to identify the specific question that you are addressing and expand on the projects. Please talk to me regularly as you think through your project!!!! A big part of the purpose of this project is for you to interact with me, and think through your project with me. The purpose is NOT for you to go off and do something entirely on your own. Nor is the purpose simply to see if you can follow the directions in someone else’s pre-canned activity. The purpose IS for you to THINK about your experiment, identify problems with it, or changes that might make it more rigorous, to MODIFY AND IMPROVE it, to try knew approaches when your first approach doesn’t work, and to TALK TO ME about the experiment and how it is going and what your results mean. I am available in my office much of the day, in class during classtime, and by e-mail.
An investigation includes several steps: Asking a TESTABLE question, developing an experimental approach, testing out the experimental approach to see if it will work, constructing the experiment and doing it (with repetitions and controls), interpreting the results, and, finally, reporting the results. To get started in your thinking, and in understanding what an experimental investigation is, you should read over the notes and discussion of investigations on my web page.
1) Experimental investigation of stream velocity, and the relationship between stream velocity and sediment size.
Part I. An outline developed by a group of area teachers
Part II. An investigation developed for 8th graders by one of those teachers based on that outline
Part III. A related activity on stream velocity and sediment size that I have done with 3rd-7th graders.
(an example project poster by Earth Science Today students)
2) Experimental investigation of the solubility of water in air as a function of temperature.
(an example project poster by Earth Science Today students)
3) Experimental investigation of the distribution of salt between ice and liquid water
4) Observational investigation of lunar cratering and Experimental Cratering Processes.
With a related companion investigation:
Experimental cratering investigations
Experimental cratering investigations in sand
5) Experimental investigation of the heatcapacity of various materials
With related companion investigations:
How do different colors of material absorb light energy differently?
How does dirt in snow affect the snow’s rate of melting (outlined in “brief examples of experimental investigations” on my web page)
6) Cookie Experiments(this is not really an earth science experiment, but might be an appropriate way to introduce elementary students to experimental investigation).
7) Experimental investigation of the relationship between air volume and temperature (outlined in “brief examples of experimental investigations” on my web page)
(an example project poster by Earth Science Today students)
8) Additional appropriate outlines for investigations might be found in the book “Two Suns and a Green Sky, Thomas Baker, 1994. Available at Concordia Library and in class.
1) Experimental investigation of stream velocity, and the relationship between stream velocity and sediment size.
Part I below is a teacher-developed outline of an experimental approach. Part II is an actual lesson developed by one of the teachers on the basis of this outline (for 8th graders). Part III is a related activity that I have done with 3rd to 7th graders.
Part I. Teacher Guided Inquiry: Stream Velocity
Group: Pat Healey, Barry Olson, Tim Somes, Mary Colson, Karl Leonard
Time frame: 2-3 weeks.
1) Pose Question to students: What variables affect stream velocity?
Brainstorm a list, with teacher guidance
Narrow options down
Example final list:
Slope
discharge
channel roughness
channel shape and size (width, depth)
2) Groups design their own experiments (kids need to know what materials they will have to work with)
Teacher must approve each design
3) Students conduct their experiments, record data, etc.
4) Groups will report results to classmates
5) Relate results to USGS stream data, for example, look at change in discharge over time.
6) Take a field trip to a local river
Part II. The following extensive activity was developed by Teacher Mary Colson for 8th graders.
Part II. This comprehensive investigation was developed by Mary Colson for 8th graders, modified from an activity in “Crusty Problems”, ISCS, 1972. It involves students developing their own questions and experimental approach.
Name ______Date ______Period ______
Laboratory Research Activities: The Force of Moving Water
Part 1 - Learning to use the setup
Introduction
Rivers and streams can be raging torrents or slow-moving trickles. Either way, they do work on our landscape, making valleys, waterfalls, flood plains, point bars, deltas and other features. In order to study the work of rivers in the classroom, it will be necessary for you to use a stream trough or a stream table. The trough and table are simplified models of a real river or stream
The stream table or stream trough will allow you to control some of the important factors that influence a river's ability to erode or deposit. In nature all of these factors operate at the same time. In the lab you'll be able to control or vary the factors that you choose. For example, you'll be able to do such things as create a meandering river, speed up the water or slow it down, make it flow through different types of material, or increase or decrease the water volume in the river channel. By controlling these variables one at a time, in your model stream, you can begin to understand how real rivers behave. NOTEBOOK - define variable
The Setup
The standard setup is similar for all the stream table or stream trough experiments. In the lab activities for our study of "The Force of Moving Water" we will begin by using a stream trough. Carefully examine the drawing below as well as the setup in the front of the classroom.
The Setup
The Materials
Each group will have an assigned set of materials, the set number should be the same as your work table number. Each set should always have the following materials:
1 supply bucket (with supply hose)a plastic lift
2 catch buckets (2/3 full of water)a beaker
a stream tablea stream trough a pink sponge
You should always check before you begin the activity to see if you have all your materials. Let me know if you do not.
Do not carry any of the buckets by the handles. Carry the catch buckets to your workstation separate from carrying the stream table. Sometimes, you'll be able to leave the stream table on the window sill.
Some materials that you will have to get from me:
1. a stopwatch (if someone in your group has a watch with a second hand that will work too)
2. a screw clamp to control amount of water coming out of the supply hose
The Variables
You will be able to easily control the following variables with your stream trough or stream table: kind of sediment on the stream bed, the rate of water flow and the slope of the stream. You will need to practice controlling the rate of water flow (Part 2) and practice setting the slope of the stream (Part 3).
Name ______Date ______Period ______
Laboratory Research Activities: The Force of Moving Water
Part 2 - Learning to control the discharge
Introduction
Most of the experiments will call for you to adjust the rate of flow of water to a certain number of milliliters per second. Doing this is easy. For example: you simply time how long it takes (in seconds for the supply hose to fill a 100 milliliter beaker. You can then calculate the rate of flow like this (the example assumes that it takes 5 seconds to fill the beaker):
100 milliliters (volume of water)= 20 ml/sec (rate of flow)
5 seconds (time)
Practice the calculation.
1. What would the rate of flow be if you filled up 100 ml in 10 seconds? Be sure to label your answer with the correct units.
2. To achieve a discharge of 5 ml/sec, how long would you have to allow for the beaker to fill up to 100 ml?
Practice adjusting the rate of flow in the supply hose.
4. READ THIS PARAGRAPH
Set up the stream trough with the lift and no boards. Put the lift as close to the closed end of the stream trough as possible. Set the supply bucket on the high chair. Next someone holds the supply hose high in the air, above the supply bucket. Another person fills the supply bucket by pouring water from one of the catch buckets. Put the screw clamp on the supply hose, tighten it so the hose flattens but is not squeezed shut. Put a finger over the open end of the hose and lower the hose into the stream trough. Place the empty catch bucket on a chair such that the water from the trough will end up in the bucket. Now remove your finger from the hose end and let the water run down the trough.
5. Change the tightness of the screw clamp and watch what happens to the amount of water coming out of the hose. Describe what happens when you tighten and loosen the screw clamp.
6. Stop the flow of water from the hose by putting the open end of the supply hose into the supply bucket or by folding the hose.
7. Now fold the hose and then loosen the screw clamp a little. Unfold the hose and let timing a small stream of water pours into your beaker. Find the 100 ml line on your beaker. I strongly recommend that you hold the beaker at the closed end of the stream trough. Remember to keep watch on how much water is in the catch bucket.
8. Empty the beaker. Time how long it takes to fill the beaker up to the 100 ml mark. Calculate the discharge.
discharge= 100 ml / time to fill to 100 ml
9. Now tighten the screw clamp a little. Repeat the instructions fro steps 7 and 8.
10. Calculate the discharge.
discharge= 100 ml / time to fill to 100 ml
11. Practice adjusting the discharge until you can get a flow of 10 ml/sec (anything between 9 and 11 sec is fine)
f. Practice adjusting the discharge until you can get a flow of 5 ml/sec. (any rate between 4 and 6 sec is fine)
3. Clean up
a. We will usually return the room to complete order.
b. Always dump the water from the supply bucket back into one of the two catch buckets.
c. Do not empty out the catch buckets in the sink unless Mrs. C. tells you to.
d. When you need to transport the stream table, two people, one on either end, should carry the stream table. Return the stream table to its correct place.
e. Place all materials listed on page 2, back in the stream table.
f. Wring the sponge out over the sink.
g. Return screw clamps and stopwatches to me.
h. Return your tables and chairs to correct position. Dry everything.
i. Sit down :-)
Name ______Date ______Period ______
Laboratory Research Activities: The Force of Moving Water
Part 3 - Varying and calculating the slope.
Introduction
Sometimes you will need to adjust the slope of the stream trough or stream table. You will need to raise the upper end of the trough or table a certain number of inches above the table. To change the slope, simply slip the plastic lift under the stream trough. Adjust the height of the closed end by either moving the lift towards the open end of the trough or by slipping a wood block or piece of cardboard under the lift. The wood and cardboard shims are located by the ______. Do not return them with your other materials to your stream table.
Practice
1. Move the plastic lift as close to the closed end as possible. What is the distance between the table top and the bottom of the stream trough? Measure in inches, to the nearest sixteenth of an inch. ______
2. Measure the "run" distance. Calculate the slope of the stream table in terms of inches per foot.
stream trough
rise
run
slope = rise (in inches)
run (in feet)
3. Move the plastic lift 13.5 inches toward the open end of the trough. If both ends of the trough rise up off the table, slide the lift back towards the closed end of the trough so that the open end rests back down on the table. Measure the height above the table of the bottom of the stream trough. Take your measurement at the closed end. ______
4. Calculate the slope of the stream table, in terms of inches per foot, for number 3.
slope = rise (in inches)
run (in feet)
5. Move the plastic lift back to the closed end of the trough and slide 2 wood boards (or 4 cardboard shims) under the lift.
6. What is the distance between the table top and the bottom of the stream trough? Measure in inches, to the nearest sixteenth of an inch. ______
7. Calculate the slope.
Let the teacher see your work before continuing on.
Name ______Date ______Period ______
Laboratory Research Activities: The Force of Moving Water
Part 4 - Effect of discharge (volume per unit time) on water velocity
Introduction
Now you will experiment to determine the effect of changes in flow volume on water velocity (speed) in your stream trough. You will use 4 different flow volumes and measure the velocity of the water in the stream trough. To measure the velocity of the water you will time how long it takes a tiny piece of styrofoam to travel the length of your stream trough. You'll need to get the styrofoam from me.
Procedure
1. Set up the stream trough as described in part 1. Keep the supply bucket half full at all times.
2. Make sure you have a black "starting line" in your stream trough, located about 3 inches from the closed end of the stream trough.
3. Elevate the trough on the plastic lift. Line the plastic lift up with the closed end of the trough. What is the slope of the trough in inches per foot? ______(you did this in Part 3)
4. Set your discharge to 20 ml/sec. Hold the hose in the trough such that the water begins to run into the trough right beginning at the closed end. Drop your bit of styrofoam into the water flow on the uphill side of the starting line and watch what happens.
5. Do step 4 again, only this time begin timing when the styrofoam crosses the line and stop timing when it leaves the stream trough. Record the value on the data table for Part 4.
6. Repeat step 5 two more times. If all three times are wildly different from one another, repeat several more times until you get some agreement among your measurements.
7. Repeat steps 4-6 again, but this time set your discharge to 15 ml/sec.
8. Repeat for discharges of 10 ml/sec and 5 ml/sec. NOTE for the lowest discharge, the bit of styrofoam will tend to get hung up. Try dropping the styrofoam in the very center of the flowing stream.
9. Graph your data on the grid provided. Put discharge on the x-axis and velocity on the y-axis. Make a line graph.
10. Use your line graph to predict the velocity of the water for 17 ml/sec. Write your prediction here______.
11. Test your prediction. Time for styrofoam to flow downstream? _____ What is your measured flow velocity when the discharge is 17 ml/sec? _____. Compare the measured value with your prediction of #10.
Data table for Part 4
The effect of discharge on water velocity
Discharge / slope(in/foot) / Time for styrofoam to travel (sec) / Average of times (sec) / Distance Styrofoam traveled / Water Velocity
(in/sec)
Trial 1 / Trial 2 / Trial 3
5 ml/sec
10 ml/sec
15 ml/sec
20 ml/sec
Name ______Date ______Period ____
Laboratory Research Activities: The Force of Moving Water
Part 5 - Effect of slope on water velocity
Introduction
Now you will experiment to determine the effect of changes in slope on the velocity of the water in your stream trough. You will keep the flow volume the same. As with Part 4, you will use a small fragment of styrofoam to help measure how fast the water is flowing.
Procedure
1. Set up the stream trough as described in Part 1. Keep the supply bucket half full at all times.
2. Elevate the trough on the plastic lift. Line the plastic lift up with the closed end of the trough. What is the slope in inches per foot? ______(You did this in Part 3).
3. Set your discharge to 10 ml/sec.
4. Hold the hose in the trough such that the water runs down the full length of the trough. Lay the piece of styrofoam at the upper end of the trough and let if flow downhill and into the bucket.