Magnetometer Extensions Activity

Type of Lesson: Hands-on Activity, Reading & Writing Exercise

Time Needed: 30 minutes

National Standards Addressed

Earth and Space Science, Grades 5-8: The solid earth is layered with a lithosphere; hot, convecting mantle; and dense, metallic core.

Earth and Space Science, Grades 5-8: Lithospheric plates on the scales of continents and oceans constantly move at rates of centimeters per year in response to movements in the mantle. Major geological events, such as earthquakes, volcanic eruptions, and mountain building, result from these plate motions.

Earth and Space Science, Grades 5-8: Some changes in the solid earth can be described as the “rock cycle.” Old rocks at the earth’s surface weather, forming sediments that are buried, then compacted, heated, and often recrystallized into new rock. Eventually, those new rocks may be brought to the surface by the forces that drive plate motions, and the rock cycle continues.

Physical Science, Grades K-4: Magnets attract and repel each other and certain kinds of other materials.

Science and Technology, Grades K-4: Tools help scientists make better observations, measurements, and equipment for investigations. The help scientists see, measure, and do things that they could not otherwise see, measure and do.

Unifying Concepts and Processes, Grades K-12: Models are tentative schemes or structures that correspond to real objects, events, or classes of events and that have explanatory power.

Quick Summary of Lesson

This activity models real-world uses of a magnetometer instrument. Students will see how sea floor spreading is related to magnetic reversals and how some ore deposits are found.


file folders
ceramic donut magnets, 1 and 1/8 inch in diameter
masking tape
marker or pen
magnetometer instrument
student worksheet available in Student Activity Sheet section below


1. Each student should complete a student worksheet found in the next section.

2. In order for the students to complete the worksheet, you will need to build two sets of prompts, a sea floor spreading model and an ore deposit model. Depending on the size of your class, you may want to build more than one of each of these models. You may also want students to use their magnetometer on a few different models you've created. No matter what the size of your class, have half of the class start on part I of the worksheet and half of the class start on part II of the worksheet.

A. Constructing a Sea Floor Spreading Model
Open file folder. Choose one side to tape magnets to. On this side, draw 2 lines, that divide the folder space into 4 equal parts (one line should be 11 inches and one line 8 1/2 inches if you are using a standard file folder). Arrange the magnets along the long line so that their polarities are symmetric on each side of the short line. For example, you may decide to place 3 magnets on either side of the short line in this order: N-S-N-line-N-S-N. Another arrangement might be N-N-S-line-S-N-N, etc. Tape the magnets in place. Close the folder and tape it shut as well. Draw the short line on the top of the folder - this represents the mid-ocean ridge.
B. Constructing a Ore Deposit Model
With the folder shut, draw a grid on the top of the folder (suggested 1 inch squares). Open file folder. Arrange any number of magnets anywhere on the bottom portion of the folder. North or south polarity can face up. Tape the magnets in place. Now close the file folder and tape shut.

Student Activity Sheet

Please click here for student activity sheets. All activities on the Windows to the Universe site may be printed and reproduced if being used for educational purposes.

Notes to the Teacher

The donut magnets used for this activity can be found at Radio Shack stores across the nation. They are relatively inexpensive at 5/$1.99. These magnets have a definite north and south pole - with the top face of the magnet being one polarity and the bottom face of the magnet being the opposite polarity.

The answers to the questions on the Student Activity sheet are as follows: C, B, A, D, B, B, A (in the order the questions are asked).

Another use of the magnetometer instrument can be explored using our Terrabagga Activity.

Need More Information? Try Using Windows to the Universe

Please use these links for further ideas or more information:
Build the magnetometer instrument
The Earth's magnetic field
The force of magnetism
Magnetic field
Magnetic material
Magnetism overview
Planetary magnetism
Solar System formation
Terrabagga activity

Last modified March 15, 2002 by the Windows Team

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