Geology & Geophysics Editors' Highlights

Frequency Dependent Plates

Rocks stretch, break, and flow, depending on how and under which conditions they are loaded. A new formulation to better capture Earth’s rheology is explored in the context of plate thickness.

Source: AGU Advances


Rocks deform as elastic solids or viscous fluids depending on pressure and temperature. If viscous and elastic mechanisms act together, the frequency of loading relative to an internal resonance can determine if the rock feels elastically weak or strong. Lau, Holtzman, & Havlin [2020] recently worked to expand such classical descriptions to a frequency-dependent viscosity, taking into account a range of microphysical mechanisms. In this perspective, the authors further explore how this framework can be used to understand contrasting estimates of lithospheric plate thickness. In particular, long-term convective loading estimates associated with thinner plates can be reconciled with shorter frequency estimates of thicker plates. The new approach sets out a blueprint how to unify the representation of a range of field and laboratory constraints for the thermo-mechanical character of the lithosphere, including how plates transition from supporting mountains to squishy folding into the mantle at subduction zones.

Citation: Lau, H., Holtzman, B., & Havlin, C. [2020]. Towards a Self-consistent Characterization of Lithospheric Plates Using Full-spectrum Viscoelasticity. AGU Advances, 1, e2020AV000205.

—Thorsten Becker, Editor, AGU Advances