Vernier Software and Technology
Vernier Software & Technology

Sea Floor Spreading

Figure from experiment 5 from Earth Science with Vernier


According to the theory of plate tectonics, the Earth’s crust is broken into many slowly moving plates. Sea floor spreading occurs at the mid-ocean ridge where two plates are moving away from each other. Here, magma rises up from below as the sea floor spreads out to either side as shown in Figure 1. This spreading occurs at about the same rate as your fingernails grow.

The pattern of sea floor spreading can be observed by studying the magnetic field of the rock on 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 rock solidifies, this magnetic “signature” is locked in place.

In this experiment, you will use a model of a sea floor spreading zone. The mid-ocean ridge is running north to south down the center of the model. You will use a Magnetic Field Sensor to map the magnetic field of your model and use it to explain how this is evidence of sea floor spreading.


In this experiment, you will

  • Use a Magnetic Field Sensor to measure magnetic field.
  • Map sea floor spreading.
  • Interpret your results.

Sensors and Equipment

This experiment features the following Vernier sensors and equipment.

Additional Requirements

You may also need an interface and software for data collection. What do I need for data collection?

Standards Correlations

See all standards correlations for Earth Science with Vernier »

Experiment 5 from Earth Science with Vernier Lab Book

<em>Earth Science with Vernier</em> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

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