Earth's Second Magnetic Field Captured in Satellite Images

Earth is a pretty wild place to live. Not only does our home planet orbit the sun at the perfect distance to sustain life, it even has its own magnetic force field that keeps us from being deep fried by our star’s radiation.

This planetary shield is primarily generated by the massive amounts of superheated, liquid iron in the Earth’s core. But data from the European Space Agency’s Swarm satellites suggests that our planet’s oceans are generating a magnetic barrier of their own. While seawater doesn’t do nearly as much as molten metal, it’s still actively working to defend our home turf.

The magnetic field created by the oceans is incredibly difficult to measure, but the array of satellites were able to track it in great detail. The team of scientists involved in this study created an animation of changes in tidal signal over a 24 hour period, which they presented at the European Geosciences Union in Austria.

Accurately tracking these oceanic readings has proven tricky because of how slight the sea’s electric forces are. Swarm’s new readings will allow scientists to better understand the mysterious electrical forces within Earth’s crust that play a role in climate change.

“Since oceans absorb heat from the air, tracking how this heat is being distributed and stored, particularly at depth, is important for understanding our changing climate,” says Nils Olsen, from the Technical University of Denmark, in a statement. “In addition, because this tidal magnetic signal also induces a weak magnetic response deep under the seabed, these results will be used to learn more about the electrical properties of Earth’s lithosphere and upper mantle.”

The Swarm satellites have given researchers a whole new perspective of how the ocean captures heat from the atmosphere and distributes it worldwide. This process doesn’t only generate a slight magnetic field but it also contributes to the global water temperatures, which affects things like weather and oceanic life.

This research is another step in understanding how deeply intertwined all of our planet’s natural processes are.