Fast asthenosphere motion in high‐resolution global mantle flow models
نویسندگان
چکیده
منابع مشابه
Superweak asthenosphere in light of upper mantle seismic anisotropy
Earth’s upper mantle includes a 200 km thick asthenosphere underneath the plates where viscosity and seismic velocities are reduced compared to the background. This zone of weakness matters for plate dynamics and may be required for the generation of plate tectonics itself. However, recent seismological and electromagnetic studies indicate strong heterogeneity in thinner layers underneath the p...
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The low-velocity zone (LVZ) is a persistent seismic feature in a broad range of geological contexts. It coincides in depth with the asthenosphere, a mantle region of lowered viscosity that may be essential to enabling plate motions. The LVZ has been proposed to originate from either partial melting or a change in the rheological properties of solid mantle minerals. The two scenarios imply drast...
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Asthenosphere is a venerable concept based on geological intuition of Reginald Daly nearly 100 years ago. There have been various explanations for the existence of the asthenosphere. The concept of a plume-fed asthenosphere has been around for a few years due to the ideas put forth by Yamamoto et al.. Using a two-dimensional Cartesian code based on finite-volume method, we have investigated the...
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[1] The shear tractions that mantle flow exerts on the base of Earth’s lithosphere contribute to plate-driving forces and lithospheric stresses. We investigate the sensitivity of these tractions to sub-lithospheric viscosity variations by comparing shear tractions computed from a mantle flow model featuring laterally-varying lithosphere and asthenosphere viscosity with those from a model with l...
متن کاملMantle convection, the asthenosphere, and Earth’s thermal history
Calculations of mantle convection generally use constant rates of internal heating and time-invariant core-mantle boundary temperature. In contrast, parameterized convection calculations, sometimes called thermal history calculations, allow these properties to vary with time but only provide a single average temperature for the entire mantle. Here I consider three-dimensional spherical convecti...
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ژورنال
عنوان ژورنال: Geophysical Research Letters
سال: 2015
ISSN: 0094-8276,1944-8007
DOI: 10.1002/2015gl063727