Have you noticed an uptick in the number of opportunities to see aurora borealis—also known as the northern lights—in the last year? While these light displays are common in polar regions such as the Arctic, they have been more visible across a number of states as of late. The reason? A surge in solar activity that directly interacts with Earth’s magnetic field.

In this blog post, we’ll explore how you can help your middle and high school Earth and physical science students understand more about Earth’s magnetic field as it relates to this real-world phenomenon using the Go Direct^® 3-Axis Magnetic Field Sensor.

Why Auroras Have Been More Visible Recently

According to a recent announcement from NASA and NOAA, solar activity is the strongest it has been in the last 11 years. This means the sun is now in a solar maximum or a “stormy state” characterized by frequent solar flares and sunspots, which intensify auroras on Earth.

Auroras occur when solar winds—charged particles from the sun—interact with Earth’s magnetic field. This interaction channels particles toward the poles, where they collide with gases in the atmosphere, creating brilliant light displays.

Understanding the Science Behind this Real-World Phenomenon

Earth’s magnetic field acts as a protective shield, deflecting most solar winds. However, when charged particles break through, they follow magnetic field lines toward the poles. These interactions produce light in much the same way as electrons flowing through gas in a neon light create different colors.

Shifts in Earth’s magnetic field also influence auroras. Over thousands of years, magnetic pole reversals occur, altering the strength and location of auroras. According to NOAA, stronger solar winds and shifts in the interplanetary magnetic field make auroras brighter, more active, and visible farther from the poles.

This shifting magnetic field can be studied by examining patterns in the rock on the sea floor, a process students can explore in the hands-on investigation below.

A Hands-On Experiment to Investigate Sea Floor Spreading

Experiment #5 from Earth Science with Vernier 

Sea floor spreading occurs at the mid-ocean ridge where two plates are moving away from each other.

_{During sea floor spreading, magma rises up from below. This spreading occurs at about the same rate as your fingernails grow.}

Scientists can explore the pattern of sea floor spreading by studying the magnetic field of the rock that makes up the sea floor. At the mid-ocean ridge, magma rises up from the mantle below and cools. As it continues to cool, iron in the rock aligns itself with the magnetic field of the Earth, much like the needle in a compass. When the magma solidifies, this magnetic “signature” is locked in place. 

While it is impossible for students to travel to the depths of the ocean to see alternating stripes of normal and reversed polarities in the sea floor, this hands-on experiment helps students investigate Earth’s magnetic fields by developing a model of the sea floor spreading zone, then analyzing and interpreting magnetic field data.

What You’ll Need

• Go Direct 3-Axis Magnetic Field 
• Device with Vernier Graphical Analysis^® 
• Sea floor spreading zone model(s), including:
  • 20” x 20” disposable aluminum cake pan
  • 6 ceramic magnets
  • Sand to fill the pan
  • Masking tape
  • Marker
  • Plastic wrap to cover the model  
• Wooden ruler

What Students Will Do

Prior to the day of the experiment, you and your students can prepare sea floor models, embedding magnets under a thin layer of sand in a pattern that mimics real-world magnetic field reversals. Each student group should have a model of the sea floor zone with magnets lined west to east under a few centimeters of sand. We recommend using an aluminum cake pan (something that won’t disrupt the magnetic field) and six ceramic magnets. Label the cardinal directions on the model using masking tape and place it on a table with the North side facing away from the student.

_{To zero the Go Direct 3-Axis Magnetic Field Sensor, students hold the sensor vertically over the area where they will be collecting data.}

In this experiment, students connect the Go Direct 3-Axis Magnetic Field Sensor to their device and launch the Graphical Analysis software. Students zero the sensor in an area free of magnetic interference.

Students then align the ruler with the 0 cm mark on the left edge of the pan, and begin data collection by positioning the sensor at the 0 cm mark and recording the readings at 1 cm intervals across the model.

_{Data-collection set up with the tip of the probe at the same height as the ruler for each reading}

After each reading, students click “Keep” and enter the corresponding distance. Once all of the data are collected, students review the graph, marking the mid-ocean ridge and drawing lines where the magnetic field crosses 0 to identify the bands of magnetic reversal. These areas can be labeled as “Normal” or “Reverse” based on the direction of the magnetic field. 

Finally, students draw arrows to show the movement of the ocean floor and discuss how magnetic reversals help explain sea floor spreading.

How It Supports 3D Standards

This experiment builds on student knowledge of Earth’s systems by engaging them in data analysis, pattern recognition, and scientific modeling. By investigating magnetic field reversals, students explore how natural systems change over time, applying the cause-and-effect relationships that drive geological processes like sea floor spreading.

Tips

• Prepare the model sea floor spreading zones ahead of time. We recommend preparing one model per small group of students.
• Cover the models with plastic wrap. 
• Use ceramic magnets rather than “flexible” magnets—ceramic magnets are inexpensive and can be found at most craft stores as well as at major online retailers.
• Experiment with the depth and spacing of the specific magnets in your models to obtain optimal results.
• Allow 45–55 minutes of class time to complete this experiment.

By understanding more about magnetic fields, students can make scientific connections and better understand what’s happening in the world around them—from the depths of the ocean with sea floor spreading to the skies above them with the aurora light displays.

Looking for more? Check out this video with Director of Physics Fran Poodry as she details magnetic field mapping with the Go Direct 3-Axis Magnetic Field Sensor and how the sensor can be used to further engage students in hands-on exploration.

Do you have innovative ways you teach students about magnetic fields using Vernier technology? Let us know at blog@vernier.com or share with us on social! Reach out to physics@vernier.com, call 888‑837‑6437, or drop us a line in the live chat.