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High-resolution lithosphere viscosity and dynamics revealed by magnetotelluric imaging
1Department of Geology, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA. ljliu@illinois.edu.
Science (New York, N.Y.)
|October 7, 2016
Summary
Magnetotelluric surveys reveal lithospheric viscosity, crucial for understanding Earth's dynamics. This method accurately models topography and mantle upwelling, offering better constraints than lab experiments.
Area of Science:
- Geophysics
- Geodynamics
- Earth Science
Background:
- Accurate lithospheric viscosity is essential for modeling geodynamic processes.
- Previous methods for determining viscosity have limitations.
Purpose of the Study:
- To infer effective lithospheric viscosity using magnetotelluric (MT) data.
- To validate the inferred viscosity through geodynamic modeling.
Main Methods:
- High-resolution magnetotelluric (MT) survey in the western United States.
- Approximation of viscosity structure from electrical resistivity.
- Geodynamic modeling incorporating the inferred viscosity.
Main Results:
- Successful prediction of short-wavelength surface topography.
- Accurate modeling of lithospheric deformation and mantle upwelling.
- Viscosity constraints superior to laboratory-based rheology.
Conclusions:
- MT imaging is a practical tool for constraining lithospheric viscosity.
- This approach enhances the understanding of continental lithosphere dynamics.
- Electrical resistivity serves as a reliable proxy for mechanical strength.
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