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Updated: Sep 4, 2025
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Constraining the Range and Variation of Lithospheric Net Rotation Using Geodynamic Modeling
Suzanne Atkins1, Nicolas Coltice1
1Laboratoire de Géologie CNRS-École Normale Supérieure-PSL University Paris France.
Journal of Geophysical Research. Solid Earth
|July 22, 2022
Summary
Lithospheric net rotation (LNR) requires high viscosity variations for Earth-like values. While its evolution is unpredictable, LNR can be treated as a Gaussian variable for plate motion models.
Area of Science:
- Geophysics
- Solid Earth Geodynamics
- Computational Geodynamics
Background:
- Lithospheric net rotation (LNR) is the solid-body movement of the lithosphere relative to the mantle.
- Distinguishing LNR from plate motion is crucial for accurate absolute plate motion models.
- LNR is challenging to quantify due to geological data uncertainties and mantle plume reference frame stability issues.
Purpose of the Study:
- Investigate factors controlling LNR magnitude using mantle convection simulations.
- Assess the statistical predictability of LNR within a self-consistent convective system.
- Provide geodynamic constraints for absolute plate motion reconstructions.
Main Methods:
- Utilized 3D mantle convection simulations.
- Analyzed the influence of viscosity variations, temperature dependence, continents, and transition zone gradients on LNR.
- Examined the statistical distribution and temporal evolution of LNR.
Main Results:
- High lateral viscosity variations are essential for Earth-like LNR values.
- Softer slabs (lower temperature dependence of viscosity) make continental presence and transition zone viscosity gradients significant for LNR.
- LNR evolution is unpredictable in the chaotic system, but its range follows a Gaussian distribution with a 5 Myr correlation time.
Conclusions:
- Approximately 50 Myr of simulation data is needed to achieve a fully Gaussian distribution for LNR.
- LNR can be statistically treated as a Gaussian variable within the timescales of absolute plate motion reconstructions.
- This study offers a novel geodynamic constraint for improving absolute plate motion models.
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