Home Store Project Ideas Project Guide Ask An Expert Blog Careers Teachers Parents Students

Is There a Whole Lot of Shaking Going On? Make Your Own Seismograph and Find Out!

Difficulty
Time Required Long (2-4 weeks)
Prerequisites You will need access to some basic wood shop tools and experience using them for this science project.
Material Availability Readily available
Cost Low ($20 - $50)
Safety Adult supervision is required when using power tools and taking measurements outdoors near traffic.

Abstract

If you live in an area where earthquakes happen, you might be especially interested in this science project. You will learn how to build your own seismograph and how to use it to detect ground motion.

Objective

Build and test your own seismograph.

Credits

Sources

This project is from:

Edited by Andrew Olson, PhD, and Teisha Rowland, PhD, Science Buddies

Cite This Page

MLA Style

Science Buddies Staff. "Is There a Whole Lot of Shaking Going On? Make Your Own Seismograph and Find Out!" Science Buddies. Science Buddies, 22 Mar. 2013. Web. 30 Aug. 2014 <http://www.sciencebuddies.org/science-fair-projects/project_ideas/Geo_p017.shtml>

APA Style

Science Buddies Staff. (2013, March 22). Is There a Whole Lot of Shaking Going On? Make Your Own Seismograph and Find Out!. Retrieved August 30, 2014 from http://www.sciencebuddies.org/science-fair-projects/project_ideas/Geo_p017.shtml

Share your story with Science Buddies!

I did this project I Did This Project! Please log in and let us know how things went.


Last edit date: 2013-03-22

Introduction

A seismograph is an instrument that detects and records ground motion. Ground motion can be caused by something man-made, such as a mine blast or a nuclear explosion; or by natural events, such as landslides, volcanic activity, or most often, earthquakes.

How does an earthquake cause ground motion? The entire outer shell of the Earth, known as the lithosphere, is made up of tectonic plates that are constantly moving. There are seven or eight large tectonic plates and many more minor ones. Where the tectonic plates meet and bump together, it is common to find mountains, volcanic activity, mid-ocean ridges, and earthquakes. (What forms depends on how exactly the tectonic plates are moving against each other at the plate boundary.) The movement of the tectonic plates also causes faults to form, which are cracks in the Earth's surface where a plate, or parts of a plate, moves in different directions. Faults are usually near the edge of a plate. When two tectonic plates (or parts of the same plate) bump or catch as they slide past each other at the fault, earthquakes usually occur. Specifically, as the plates rub together, when they catch and get stuck it results in a build up of pressure because the rocks want to move but cannot. Eventually, some rocks break and the pressure is released as the plates suddenly move. This causes waves of energy, known as seismic waves, to travel through the Earth, making the ground shake. Where the rocks broke is known as the earthquake's focus, and right above this point, up on the ground, is called the earthquake's epicenter.

It is seismic waves from an earthquake or other natural events that a seismograph picks up. There are two main types of waves: body waves, which can travel through the inner layers of the earth, and surface waves, which can only travel on the surface. Body waves are the fastest and have the highest frequency. The first type of body wave is called the primary or P-wave. It pushes and pulls the solid rock or liquid matter that it is moving through, and people feel it as back-and-forth or side-to-side motion. The second type of body wave that you feel in an earthquake is called the secondary or S-wave. S-waves cannot move through liquids, only through solid rock. They move rock particles perpendicular to the direction the wave is traveling in. Do not miss the exciting wave animations in the Bibliography where you can see body waves and surface waves in action on rock particles!

Watch DragonflyTV earthquake video
Click here
to watch a video of this earthquake investigation, produced by DragonflyTV and presented by pbskidsgo.org.

Did you know you can see evidence of the power of seismic waves all around the San Francisco Bay area? Watch the DragonflyTV video and follow Claire and Nisha as they discover signs of earthquakes in the roads, buildings, and ground all around their neighborhood.

So how does a seismograph measure seismic waves? Imagine trying to draw a straight line on a piece of paper while someone is holding your elbow and jiggling it back and forth. It would be hard to get the line straight. A simple seismograph is kind of like your arm holding a pen. A horizontal beam (like your arm) holds the pen. The "elbow" end of the rod (the stand) is connected firmly to a sturdy vertical post, as shown in Figure 1 below. To keep the beam from moving from small vibrations, a heavy weight is attached to the beam. The pen writes on paper mounted on a roll, which is turned at a constant speed (either by hand, or with a motor). Shaking of the ground causes the vertical stand to move up and down. This, in turn, causes the horizontal beam to jiggle back and forth. So instead of a straight line on the paper, the pen makes back-and-forth motions to draw squiggly lines. The greater the vibration, the greater the height of the squiggles, meaning the greater the intensity of the seismic waves.

diagram of home-made seismograph
Figure 1. This is a diagram of a homemade seismograph. (UC Regents, 1995.)

The lines drawn by the seismograph result in what is called a seismogram. In this geology science project, you will build your own seismograph and see how well it can record ground vibrations.

Terms and Concepts

  • Seismograph
  • Earthquake
  • Tectonic plates
  • Faults
  • Seismic wave
  • Epicenter
  • Body wave
  • Surface wave
  • Frequency
  • Primary wave (P-wave)
  • Secondary wave (S-wave)

Questions

  • What causes an earthquake?
  • How are seismic waves caused by an earthquake?
  • How does a seismograph record seismic waves?
  • Do you think your seismograph will be able to detect vibrations from someone jumping up and down nearby?

Bibliography

For getting started on your background research, here are some good references on seismology and how to build a seismograph:

Materials and Equipment

  • Wood base, 10" x 24" x 0.5"
  • Wood stand, 2" x 4" x 12"
  • Various sizes of nails
  • Strong wire or non-elastic thick rope or twine (7 feet total)
  • Wood support blocks, approximately 2" x 4" x 8" (2)
  • Roll of adding machine paper with a width of at least 2"
  • Smooth-sided can with lid and base, similar dimensions as paper roll
  • Wood dowels, diameter = 0.25", length = 10"; one dowel must slide through center of adding machine paper roll (3)
  • Hand drill and drill bits. The drill bits should be the right size for making holes for the wood dowels to snugly fit into.
  • Wood beam, 1" x 1" x 20"
  • Pen
  • Round-headed screw, or bolt or nail; 1" long
  • Brick or other compact heavy weight
  • Strong tape, such as masking, strapping, or duct, for attaching weight
  • Optional: Adult helper
  • Lab notebook

Share your story with Science Buddies!

I did this project I Did This Project! Please log in and let us know how things went.

Experimental Procedure

Building the Seismograph

  1. This science project follows the Engineering Process. To learn more about the Engineering Process, and how it is different from the science projects that follow the Scientific Method, see this Science Buddies resource on Engineering & Programming Project Tips.
    1. For this science project, students are expected to design their own seismograph, test it, and then improve it if necessary. Basic steps are given to help guide students through the process.
    2. You can find additional information about this process from The Engineering Design Process resource.
  2. Determine how you will build the seismograph based on the diagram in Figure 1 in the Background tab and then build it. You may want to have an adult help you build the seismograph. When building the seismograph, here are some important steps and/or modifications you may need to consider:
    1. On the wood base, you will want to attach the wood stand so that it is positioned vertically on (and near one end of) the base.
      1. Fasten the wood stand securely to the wood base, such as by nailing upward from underneath the wood base.
      2. You can attach wire (or cord) between the wood stand (on its back and sides) and the base to help to keep the stand stable.
    2. Attach the mounted paper roll (roll of adding machine paper) and take-up spool (smooth sided can) on the other end of the base.
      1. Mount the paper roll and take-up spool to the wood support blocks before attaching everything to the base.
        • Figure out how best to arrange the paper roll and take-up spool on dowels attached to the wood support blocks.
        • Both the paper roll and take-up spool should be able to rotate. The take-up spool should rotate when you crank its wood dowel; the paper roll can turn either with its wood dowel or separately from the dowel.
        • If you want to be creative, see if you can devise a way to make the paper roll feed onto the smooth can automatically so that you do not have to crank the can by hand. You might try buying a miniature battery-operated motor that can turn the wood dowel of the can.
        • Tape down the end of the paper roll onto the can so that when you crank the can, the paper should wind up around the can and cause the paper roll to rotate as it feeds paper to the can.
        • If you have a drill, you can mount the two wood dowels in holes drilled through the two wood support blocks. If you do not have a drill, saw two slots into the upper edge of each wood support block and then drop the dowels into these slots.
    3. Before attaching the beam to the stand, you can attach a pen to the end of the beam.
      1. You can do this by using a hand drill to drill a hole through the end of the beam and placing a pen in the hole.
      2. The pen must write easily when pulled down onto the paper roll by the brick. Cap it when not in use. You may try substituting a soft lead pencil, a charcoal pencil, a crayon, etc.
    4. To attach the beam to the stand, you can use a hand drill to drill holes in the beam and stand and then connect them together with a wooden dowel.
      1. When deciding how high to attach the beam on the stand, consider what the height of the mounted paper roll is.
      2. To make the wood beam hang level over the base, you can fasten the round-headed screw, bolt, or nail securely into one end of the wood beam. This screw will rest against the wood stand, making the wood beam hang level. To help the screw stay in place and not slip off of the wood stand, drill or carve a small hole 1/4-inch deep out of the stand and slightly larger in diameter than the screw head. The head of the screw can sit in this hole and press against the wood stand.
    5. Attach a weight (brick) to the beam to keep it from moving due to tiny vibrations.
      1. Make sure the pen writes easily when pulled down onto the paper roll by the brick.

Testing the Seismograph

Here are some ideas for testing the seismograph. You can probably think of other ideas on your own. As you test your seismograph, think of ways in which you can improve it. Can you make your original design even better? You can make some adjustments and test it again to find out.

  1. Have a helper jump up and down on the floor near the seismograph.
    1. How does the seismogram change as the jumping person moves farther away? Make measurements with the person at a distance of 0.5, 1, 2, 4, 8, and 16 meters (m) away from the seismograph. Make a graph of seismogram peak height (in centimeters [cm], on the y-axis) vs. distance of your helper from the seismograph (in m, x-axis). You could also use the seismograms themselves on your display board.
    2. How does the seismogram change if the person jumping is heavier or lighter? Pick a distance from your first experiment where the pen moved noticeably, but did not cover its full range of motion on the paper. Make a series of seismograms with helpers of different weights jumping up and down at that fixed distance from the seismograph.
    3. How does the seismogram change when you vary the substrate on which it is standing? For example, compare placing the seismogram on a wooden floor vs. a concrete slab (like your garage floor), or on a table vs. directly on the floor, or on your lawn vs. a hard-surfaced playground.
  2. Safety note: adult supervision required for outdoor measurements near traffic. You could also try your seismograph at different locations outdoors. For example, if you place the seismograph on a sidewalk, can you see vibrations from nearby foot or vehicle traffic? Can you identify when larger vehicles, such as trucks or buses, pass by?

Share your story with Science Buddies!

I did this project I Did This Project! Please log in and let us know how things went.


Variations

  • What do you think will happen if you use a lighter weight on the horizontal rod of your seismograph? If you use a heavier weight?
  • Another way to test the seismograph would be to drop a box containing objects with increasing mass at different distances from the seismograph. For example, you could use 20-pound sacks of dry rice, or an increasing number of books. Use a bathroom scale to measure the weight of the box. You can also try this test on different substrates (wood floor vs. concrete slab).
  • Advanced: Can you think of ways to improve the seismograph? Or can you think of different way to measure seismic waves? Draw a clear diagram that shows and labels all parts. Then write a paragraph explaining how your design works. Here are some important considerations as you are coming up with your design:
    • Is it made of common inexpensive materials found in a local store?
    • Will it be able to determine the relative magnitude (size) of each vibration it measures?
    • Will it be able to measure vibrations continuously for at least 1 minute?
    • Will it be able to measure even slight vibrations (such as a person jumping up and down next to your seismograph)?
    Gather the materials you need and build the seismograph you designed. Be prepared to show other students how your device works (UC Regents, 1995).
  • For a project using data from state-of-the art seismographs that you can access online, see the Science Buddies project How Fast Do Seismic Waves Travel?
  • For a more advanced project that uses seismometer data, try the Science Buddies project Locating the Epicenter of an Earthquake.

Share your story with Science Buddies!

I did this project I Did This Project! Please log in and let us know how things went.

Ask an Expert

The Ask an Expert Forum is intended to be a place where students can go to find answers to science questions that they have been unable to find using other resources. If you have specific questions about your science fair project or science fair, our team of volunteer scientists can help. Our Experts won't do the work for you, but they will make suggestions, offer guidance, and help you troubleshoot.

Ask an Expert

Related Links

If you like this project, you might enjoy exploring these related careers:

Mechanical engineer building prototype

Mechanical Engineer

Mechanical engineers are part of your everyday life, designing the spoon you used to eat your breakfast, your breakfast's packaging, the flip-top cap on your toothpaste tube, the zipper on your jacket, the car, bike, or bus you took to school, the chair you sat in, the door handle you grasped and the hinges it opened on, and the ballpoint pen you used to take your test. Virtually every object that you see around you has passed through the hands of a mechanical engineer. Consequently, their skills are in demand to design millions of different products in almost every type of industry. Read more
Geoscientist from Chevron

Geoscientist

Just as a doctor uses tools and techniques, like X-rays and stethoscopes, to look inside the human body, geoscientists explore deep inside a much bigger patient—planet Earth. Geoscientists seek to better understand our planet, and to discover natural resources, like water, minerals, and petroleum oil, which are used in everything from shoes, fabrics, roads, roofs, and lotions to fertilizers, food packaging, ink, and CD's. The work of geoscientists affects everyone and everything. Read more
female mechanical engineering technician

Mechanical Engineering Technician

You use mechanical devices every day—to zip and snap your clothing, open doors, refrigerate and cook your food, get clean water, heat your home, play music, surf the Internet, travel around, and even to brush your teeth. Virtually every object that you see around has been mechanically engineered or designed at some point, requiring the skills of mechanical engineering technicians to create drawings of the product, or to build and test models of the product to find the best design. Read more

Looking for more science fun?

Try one of our science activities for quick, anytime science explorations. The perfect thing to liven up a rainy day, school vacation, or moment of boredom.

Find an Activity