Earth

Unusual Melting May Affect Key Processes Deep Within the Earth

Unusual Melting Behavior May Affect Key Processes Deep Within the Earth

The peak in viscosity of ferropericlase, the second most abundant mineral in the Earth, at ~1000 km may cause the stagnation of subducting slabs and the deflection of rising plumes. Credit: Jie Deng

New research from Yale University suggests that the unusual melting behavior of the second most abundant mineral in the Earth may affect key processes deep within the Earth.

Research by geoscientists at Yale suggests that convection in Earth’s mantle — the slow movement of rocks circulating beneath the surface, caused by heat from inside the Earth — is affected by how ferropericlase melts at high pressures.

The findings appear online December 8 in the journal Nature Communications.

“The melting temperature of most materials increases as one increases pressure, and for ferropericlase this is true except at depths between ~1000 and 1500 km,” said Kanani Lee, the study’s principal investigator and an associate professor of geology and geophysics at Yale.

Jie Deng, a Yale graduate student and the paper’s lead author, added, “We use this change in melting behavior to scale how the mantle’s flow responds and found the viscosity of this material would be at a maximum at ~1000 km, corresponding to the peak in melting temperature. This increase in viscosity would cause subducting slabs to stagnate and rising plumes to be deflected at this depth.”

Plate tectonics drive oceanic slabs deep into the mantle, generating large earthquakes at relatively shallow depths. The slabs continue to sink, but some of them flounder at ~ 1000 km, such as the slabs under Tonga, the Philippines, and Japan.

Additionally, hot rock rising from near the core-mantle boundary forms conduits, called plumes, that feed some volcanism at the surface. Hawaii and Iceland are such hotspots whose plumes are deflected at ~ 1000 km depth, which may affect the surface expression of volcanism in those locations.

Publication: Jie Deng & Kanani K. M. Lee, “Viscosity jump in the lower mantle inferred from melting curves of ferropericlase,” Nature Communications 8, Article number: 1997 (2017) doi:10.1038/s41467-017-02263-z

The National Science Foundation supported the research.

Share
By
Jim Shelton, Yale University

Recent Posts

Just Like Humans – More Intelligent Jays Have This Characteristic

Similar to humans, more intelligent jays display more self-control.  According to recent research, Eurasian jays…

December 3, 2022

Ride Along With Artemis Around the Moon [Official NASA Video]

Cameras on NASA’s Space Launch System (SLS) rocket and Orion spacecraft give us amazing views…

December 3, 2022

What Lies Beneath Yellowstone’s Volcano? Twice As Much Magma As Thought

Researcher’s expertise, energy, and empathy leave a legacy. Late MSU researcher Min Chen contributed to…

December 3, 2022

New Innovative System Evaluates the Habitability of Distant Planets

A computerized system categorizes planet atmospheres and determines which are viable for future settlement by…

December 3, 2022

New Catalyst Can Turn a Smelly Gas Byproduct Into a Cash Cow

A catalyst activated by light converts hydrogen sulfide into hydrogen energy in one step. Engineers and…

December 3, 2022

Scientists Discover That Binge-Eating Sweet Treats Is Influenced by Gut Microbiome

Gut Microbes Influence Binge-Eating of Sweet Treats in Mice We have all been there. You…

December 3, 2022