Taxonomy term

magnetism

Dangers of Van Allen Belts driven by "local acceleration"

Between about 13,500 and 58,000 kilometers above Earth’s surface, billions of high-energy particles — predominately electrons — congregate to form the outer Van Allen Belt. Nearly 4,000 kilometers closer to Earth, the outermost boundary of its twin, the second Van Allen Belt, also encircles the planet.

25 Oct 2018

Rethinking Pangea? Ancient ocean crust challenges supercontinent theory

The oldest piece of undisturbed oceanic crust ever discovered has been found beneath the eastern Mediterranean Sea, hidden under more than 10 kilometers of sediment. This ancient crust — estimated at up to 100 million years older than the oldest oceanic crust previously known — could reshape our view of global tectonics and the supercontinent cycle.

21 Dec 2016

Magnesium part of Earth's magnetic field engine

Earth’s magnetic field, which arises from convective flows in the planet’s core, known as the geodynamo, has existed for at least 3.4 billion years, meaning that the field-generating processes must have existed for that long as well. But what exactly those processes have looked like throughout Earth’s history, particularly early on, has been poorly understood. In a new study, researchers suggest that magnesium mineral formation in the core is a previously unrecognized but important piece of the puzzle.

26 Apr 2016

Of molten iron and magnetism

Since 1999, the German satellite CHAMP (CHAllenging Mini-satellite Payload) has swirled around Earth, keeping watch as the planet’s magnetic field waxes and wanes over time. CHAMP’s continuous measurements of Earth’s field have created a finely detailed picture of how the field changes both in space and in time — and by extension, how the movement of the molten iron in Earth’s outer core ebbs and flows. And thanks to these data, researchers report, they can now track even small-scale, rapid fluctuations in the field’s strength around the planet.

28 Aug 2008