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Make Your Own Seismograph

Make Your Own Seismograph

A seismograph is an instrument used by scientists to measure the motions of the Earth's surface.

A seismograph is a simple pendulum. When the ground shakes, the base and frame of the instrument move with it, but the pendulum bob in place. It will then appear to move, relative to the shaking ground. As it moves it records the pendulum displacements as they change with time, tracing out a record called a seismogram.

You can make your own Seismograph to track the movement of the New Madrid Fault.

What you will need:

• Cereal box
• Cardboard sheet (size of cereal box)
• Plastic cup with cover
• Pencil
• Scissors
• Strip of paper (2" wide, by 2' long)
• Piece of string
• Rubber bands
• Sand 

Instructions:

1. Cut a rectangle out of both sides of a cereal box, leaving 1 inch wide edges.
2. Cut in the middle of the bottom edge, two narrow horizontal slots about 2 inches wide through which you can slide the 2 foot long strip of paper.
3. Pierce a hole at the center of the top cup cover and another at the bottom of the cup.
4. Push a pencil, point down, through the two holes.
5. Fill the cup with sand around the pencil.
6. Thread string through the holes near the top of opposite sides of the cup.  Hang the cup from the center of the cereal box by tying the string around a small stick at the center at the box top.
7. Adjust the length of the string so the tip of the pencil touches the strip of paper threaded through the bottom cuts of the box.
8. Glue the bottom of the cereal box to one of the sheets of cardboard.
9. Shake the cardboard base back and forth.  The weighted pencil should stay put and will make a mark on the paper strip you have moved through the cardboard base.  You will need a friend to guide the strip of paper through the slits.