George Amulele
Case Western Reserve University, OH·Earth & Environmental Science
Deep inside Earth, some subduction zones show unusually high electrical conductivity at depths greater than about 300 km. Subduction zones are places where one tectonic plate sinks beneath another into the mantle.
- Fields
Earth & Environmental Science
Materials Science
Physics
- Topics
subduction zones
subducted continental crust
liebermannite
- Grants
- 1 known grant, through Nov 2026
What they work on
- Measure the electrical conductivity of pure potassium liebermannite and potassium–sodium mixtures across pressure and temperature, using impedance spectroscopy in a multi-anvil high-pressure device.
- Measure potassium self-diffusion and sodium–potassium interdiffusion in liebermannite under similar conditions to identify the mechanism of its possibly superionic conduction.
- Test whether liebermannite's conductivity depends on crystal orientation, to judge whether subducted continental crust is electrically anisotropic.
- Combine the new data with published mineral data to model the conductivity of subducted continental crust and test whether 'dry' crust explains high-conductivity zones deeper than 300 km.
More about the research
The high conductivity is usually blamed on water-rich fluids released from the sinking plate. This project tests another idea. Continental crust can also be dragged down, and at extreme pressure it forms liebermannite, a mineral with the formula (K,Na)AlSi3O8. Materials with a similar structure often show superionic conductivity, in which ions and vacancies (empty sites) move through the solid and carry charge. This type of conductivity needs no fluid at all.
Why it matters
This work could improve how geophysicists read magnetotelluric surveys, which map underground electrical conductivity from the surface. It could help them identify where continental crust has been recycled into the deep mantle. This adds to understanding of how Earth recycles its crust. The findings on superionic conduction may also be useful in materials science.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Susannah Dorfman
Michigan State University, MI·Earth & Environmental Science
Measure the sodium content of ferropericlase, (Mg,Fe)O, under sodium-saturated lower-mantle conditions, using laser-heated diamond anvil cells that reproduce deep-Earth pressures and temperatures.
Maureen Long
Yale University, CT·Earth & Environmental Science
Image the New England crust at high resolution using hundreds of nodal seismometers spaced 500 m apart, analyzing both distant earthquake waves and background seismic noise to reveal how supercontinent cycles and mountain-building shaped it.
Jason Nicholas
Michigan State University, MI·Materials Science
Test whether the previously observed shift in the wadsleyite-to-ringwoodite transformation can be reproduced in anhydrous Mg2SiO4 thin films grown by pulsed laser deposition, using diamond anvil cells with synchrotron X-ray diffraction and Raman spectroscopy.
The school
Case Western Reserve University: 34 labs on PI Pages, $643M a year on research, 213 research doctorates a year.
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