Earth's crust is dripping 'like honey' into its interior under the Andes

Scientists have found that our planet's hot interior is dripping like honey from the Earth's crust.

There is compelling evidence that the Earth's crust has been "avalanched away" across hundreds of miles in the Andes after being swallowed up by the mantle.

The process, known as lithospheric dripping, has been going on for millions of years and in multiple locations around the world, but scientists have only recently learned about it. The researchers wrote about their findings in the journal Nature: Communications Earth & Environment.

The magnetic wave found through Earth's core is completely new.

Julia Andersen, a researcher and PhD candidate in Earth sciences at the University of Toronto, said that they have confirmed that a large portion of the Earth's upper mantle is below the surface. It dripped like cold syrup or honey deeper into the planetary interior and is likely responsible for two major tectonic events in the Central Andes.

The outer regions of the Earth's geology can be broken down into two parts: a crust and upper mantle that form rigid plates of solid rock, the lithoosphere, and the hotter, more pressurized plastic- like rocks of the lower mantle. The plates can be pulled apart to form oceans, rubbed against one another to cause earthquakes, slide one under the other, or expose a gap in the plate to the mantle. Scientists are beginning to observe other ways that mountains can be created.

The lower part of the planet's mantle is the location of the long, heavy droplets created when two collided and crumpled up lithospheric plates. The basin on the surface is formed as the weight of the droplet tugs on the surface above. Eventually, the droplet's weight becomes too much for it to remain intact, and its long lifeline snaps, and the crust above it springs upward across hundreds of miles. Researchers have long suspected that such stretching contributed to the creation of the Andes.

There is a 1,120-mile-long (1,800 kilometer) expanse of the Central AndeanPlateau that spans from northern Peru through Bolivia and southwestern Chile. It was created by the subduction of the South American plate. The process pushed the crust into the air and created mountains.

Subduction is only one part of the story. The slow and steady upward push of the subduction process can't explain some of the features on the Central AndeanPlateau. The parts of the Andes that look like they sprung from sudden upward pulse in the crust are from the Cenozoic era. The Puna is higher than the Altiplano and has volcanic centers.

There are signs of water dripping. To be certain, the scientists needed to model the ground of the plateau. They used polydimethylsiloxane (PDMS) and a mixture of PDMS and modeling clay to create a simulation of Earth's mantle and lower mantle.

Under incredibly precise sub-millimetre measured conditions, it was like creating and destroying mountain belts.

The team created a small, high-density instability just above the lower mantle layer of their model, recording with three high-resolution cameras as a droplets slowly formed and then sagged into a long, dilated drip. You can see the change if you check every few hours.

The researchers saw a similarity between the images of their model's surface and the aerial images of the geological features of the Andes.

We're confident that the cause of the observed deformations in the Andes is a drip, because we observed crustal shortening with folds in the model and basin- like depressions on the surface.

The researchers said their new method provides solid evidence for how some key features of the Andes formed, as well as highlighting the significant role of geological processes other than subduction in the shaping of Earth's landscapes. It is possible that it can be used to spot the effects of other types of subsurface dripping around the world.

It was originally published on Live Science