Seismic 'Telescope' Reveals a Titanic, Tree-Like Plume Feeding Earth's Volcanoes [View all]

[Judi Lynn]

By Jason Dorrier -Oct 17, 2021

Some 75% of the world’s volcanoes live along the aptly name Ring of Fire. This makes sense. Hugging a boundary between tectonic pates, the Ring of Fire is an open seam on the planet’s interior. But then there’s Hawaii, a chain of volcanic islands smack in the middle of the Pacific plate, far from any boundaries. What feeds its fire?

Scientists have long theorized that columns of superheated rock—piping hot plumes pushing through the mantle to the crust above—explain the Hawaiian islands and other areas like them. Where these columns touch the surface, volcanic hotspots form and the ground erupts. Over millions of years, inch by inch, the Earth’s tectonic plates drag new ground over hotspots and form long volcanic chains.

The theory is old, but actually observing the mantle plumes feeding these hotspots in any detail is fairly new. “Theoretically, we know [plumes] have to exist,” Harriet Lau, a University of California, Berkeley geophysicist told Quanta Magazine. “But they’re just so hard to see seismically.”

Now, however, in a particularly striking example, a team of scientists have completed a map of the underworld nearly a decade in the making.

The result, beautifully visualized below for a feature in Quanta, is one of the most detailed snapshots yet—and it’s surprisingly complicated. Instead of a simple vertical column rising through the mantle, the structure is tree-like, with roots near the core, a trunk mid-mantle, and finer branching structures sprouting near the surface.

More:
https://singularityhub.com/2021/10/17/seismic-telescope-reveals-a-titanic-tree-like-plume-feeding-earths-volcanoes/