Environment

Huge Plume of Magma Under the Galápagos

A fleet of floating robots has figured out why the Galápagos Islands exist. And, according to the robots’ creators, the discovery could help explain why the Earth isn’t a floating ball of ice.

The Galápagos Islands are a volcanic archipelago in the Pacific Ocean, about 600 miles (1,000 kilometers) off the coast of Ecuador. The islands are most famous as hosts to a large number of species not found anywhere else in the world, which helped the biologist Charles Darwin develop the theory of evolution. Now, according to an international team of researchers, we know that the islands were formed by a thin tunnel bringing magma up from a “mantle plume” 1,200 miles (1,900 km) below the surface. Scientists had suspected such a plume might exist before, but this is the most direct evidence yet that it’s down there.

“Mantle plumes” are giant bubbles of very hot magma that sit much closer to the Earth’s crust than usual. For decades, scientists have proposed that plumes like this could explain why certain regions of the planet are very volcanically active, even though they’re far from the edges of tectonic plates where volcanism is more expected. (Hawaii is a famous example.) Not every volcanologist accepts this explanation, but those who do think it explains why the Earth hasn’t run out of heat. The result would be a kind of trickle effect, where the hot innards of the planet would release enough geothermal heat to keep the crust warm, but not so much that it burned itself out.

Magnetic North Pole’s ‘Pretty Fast’

The US National Oceanic and Atmospheric Administration tends to update the location of the magnetic north pole every five years, but the latest update came nearly a year ahead of schedule because the pole is moving so quickly.

Earth’s magnetic north pole — the north that your compass points toward — is leaving the Canadian Arctic and moving towards Russia’s snowy Siberia at a rate of more than 55 kilometres (34 miles) per year, according to an update by the US National Oceanic and Atmospheric Administration and the British Geological Survey.

In general, the World Magnetic Model (WMM) is updated at five-year intervals to ensure modern navigation keeps up with the changes in the Earth’s magnetic field.

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