Earth Generates A Mysterious Magnetic Wave Every 7 years

Space.com

ESA’s Swarm satellite mission has discovered a mysterious magnetic wave that "oscillates every seven years and propagates westward at up to 1500 kilometers (932 mi.) a year."  Credit: ESA

Transcript

00:00Earth's magnetic field protects us from harmful particles in the solar wind.

00:12It extends deep into space, but is generated deep within our planet.

00:20By using satellites to measure fluctuations in the magnetic field, scientists are gaining

00:24new insights into Earth's interior.

00:29Unlike fixed observatories on Earth's surface, satellites can measure the magnetic field

00:33both globally and in great detail.

00:37The magnetic field is generated by swirling liquid iron in the outer core, which acts

00:41like a giant dynamo.

00:44Measurements from ESA's Swarm satellites have revealed a new type of wave motion mapped

00:48at the core-mantle boundary.

00:55The wave oscillates around every seven years, propagating westward at 1,500 km a year.

01:07Combining these observations with a computer model of the geodynamo explains the source

01:12of magnetic field variations initially detected on the ground.

01:37Future measurements from space could help us understand more about the electrical properties

01:41of the lower mantle, and about the magnetic field from deep in the fluid core.

01:48This research has important implications for our understanding of the geodynamo, the structure

01:52of the outer core, and the thermal history of Earth.

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