Ocean Tides and Magnetic Fields

  • Released Friday, December 30, 2016
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Earth’s magnetic field is built up from many contributing sources ranging from the planet’s core to the magnetosphere in space. Untangling and identifying the different sources allows geomagnetic scientists to gather information about the individual processes that combine to create the full field.

One contributor is the ocean. But how do the tides affect Earth’s magnetic field? Seawater is an electrical conductor, and therefore interacts with the magnetic field. As the tides cycle around the ocean basins, the ocean water essentially tries to pull the geomagnetic field lines along. Because the salty water is a good, but not great, conductor, the interaction is relatively weak. The strongest component is from the regular lunar tide that happens about twice per day (actually 12.42 hours). Other contributions come from ocean swell, eddies, and even tsunamis.

The strength of the interaction also depends on the temperature of the ocean water. Scientists are now able to determine how much heat is being stored in the entire ocean, from wave top to sea floor by observations of the Earth's magnetic field.

The animation of ocean tide displacement.

The color bar for ocean tide displacement.

The color bar for ocean tide displacement.

The animation of ocean magnetic fields synthesized by a simulation model.

The animation of ocean magnetic fields observed by satellites.

The color bar for ocean magnetic fields.

The color bar for ocean magnetic fields.

Credits

Please give credit for this item to:
NASA's Scientific Visualization Studio

This page was originally published on Friday, December 30, 2016.
This page was last updated on Sunday, January 5, 2025 at 11:16 PM EST.