Tectonic plates

Scientists have discovered a new layer of partly molten rock under the Earth's crust that might help settle a long-standing debate about how tectonic plates ...

"But I think it drives us to see these observations of melt as a marker of what's going on in the Earth, and not necessarily an active contribution to anything." Intrigued by signs of partly molten rock under the crust, Hua compiled similar images from other seismic stations until he had a global map of the asthenosphere. The research was funded by the U.S. "But what we found is that even where the melt fraction is quite high, its effect on mantle flow is very minor." Although the Earth's interior is largely solid, over long periods of time, rocks can shift and flow like honey. The asthenosphere is important for plate tectonics because it forms a relatively soft boundary that lets tectonic plates move through the mantle.

The discovery of this hidden molten rock layer shows that molten rocks have nothing to do with tectonic plate movements, which cause earthquakes.

Models of tectonic plates and the asthenosphere can be further refined now to better reflect this, which can also help progress more research. The researchers looked at their map of the partially molten rock areas and compared it with data regarding tectonic plate movement. In fact, this recent study confirmed as much, finding that molten rock content didn't have any discernable association with the flow of the mantle. There have been theories behind the layer's softness, the most prominent of which being that molten rocks may have been behind it. This is another region of the Earth's outer layers, located below the lithosphere in the upper mantle. What isn't understood is why the asthenosphere is soft in the first place.

Using seismic waves, scientists detect widespread partially molten rock hidden under the Earth's tectonic plates in a new way, a step in settling a ...

“This study is fundamental to understanding why the asthenosphere — the weak mantle layer below the tectonic plates that enables the plates to move — is in fact weak,” said Karen M. “When we think about something melting, we intuitively think that the melt must play a big role in the material’s viscosity,” said Hua, who is now a postdoctoral fellow at U.T. The findings also show, rather surprisingly and counterintuitively, that this layer of partly melted rock doesn’t make the asthenosphere any softer or easier for tectonic plates to traverse, suggesting it plays little role in enabling plate tectonics.

The new Layer found hidden under the earth's crust could shed light on tectonic plate movement, according to the researchers. A long-running controversy.

Intrigued by indications of partially molten rock under the crust, Hua gathered comparable photos from other seismic sites to create a worldwide map of the asthenosphere. Although the Earth’s core is mostly solid, rocks may move and flow like honey over extended periods of time. As a relatively supple border that permits tectonic plates to migrate through the mantle, the asthenosphere is crucial for plate tectonics. Previously, scientists hypothesized that molten rocks may play a role. Patches of melt have previously been found by researchers at a comparable depth. However, the causes behind its softness remain unknown.

Scientists recently discovered an anomaly in Earth's interiors. This anomaly is a unique layer of molten rocks that is now known as "melt."

[science](/science) The fact it is unrelated to things we know means that maybe it serves an unexplored purpose beneath the Earth’s crust. According to UTA researchers, the asthenosphere comprises hot molten rocks and functions as a “soft boundary,” allowing smooth movement of tectonic plates via the mantle (the region between Earth’s core and crust). They argue that just because the new layer doesn’t affect plate tectonics, it doesn’t imply, it’s of no importance. Moreover, tectonic motion is so powerful; that it could also lead to the formation of new mountain ranges and even new continents. For instance, melt is found to have no influence on mantle flow, and therefore, it doesn’t affect tectonic motion.

The asthenosphere plays a fundamental role in present-day plate tectonics as its low viscosity controls how convection in the mantle below it is expressed ...

DOI: [10.1038/s41561-022-01116-9](https://doi.org/10.1038/s41561-022-01116-9) They discovered a new layer of partly molten rock under the Earth’s crust that might help settle a long-standing debate about [how tectonic plates move](https://www.techexplorist.com/molten-rock-located-under-tectonic-plates-encourages-move/35842/). In reality, what they had thought to be an aberration was widespread, showing up on seismic data wherever the asthenosphere was hottest. But we found that even where the melt fraction is quite high, its effect on mantle flow is minor.” However, the causes of its softness are not fully known. The asthenosphere’s origin, including partial melting’s role in reducing its viscosity and facilitating deformation, remains unclear.

The findings can help make models of the Earth simpler as it shows the melt layer has no major influence on plate tectonics ...

Even though the melt layer extended over most of the planet, the researchers found no correlation between the global melt map and tectonic movement. The researchers followed up on intriguing seismic readings that had found pieces of partially molten rock in the asthenosphere, and found the layer was persistent in a global map compiled from a number of seismic stations around the world. Researchers have discovered a layer of partially molten rock 160 kilometres beneath the surface of the Earth in the asthenosphere, located right beneath the lithosphere in the upper mantle.