Related Experiment Video
Updated: Jun 29, 2026
07:58
Data Processing Methods for 3D Seismic Imaging of Subsurface Volcanoes: Applications to the Tarim Flood Basalt
Published on: August 7, 2017
Deep-mantle high-viscosity flow and thermochemical structure inferred from seismic and geodynamic data
1Department of Earth Sciences, University of Western Ontario, Biology & Geology Building, London, Ontario, N6A 5B7 Canada. aforte@uwo.ca
Nature
|April 27, 2001
Summary
Geophysical data reveal a highly viscous layer in Earth's mantle near 2,000 km depth. This layer impacts mantle flow, suppressing deep mixing and supporting active mega-plumes.
Area of Science:
- Geophysics
- Earth Science
- Mantle Dynamics
Background:
- Surface geophysical data offer insights into mantle rheology and density.
- Thermal convection is a key process governing mantle dynamics.
Purpose of the Study:
- To investigate the rheological properties of Earth's mantle using geophysical data.
- To model mantle flow and its implications for deep mantle structure and dynamics.
Main Methods:
- Analysis of surface geophysical data related to thermal convection.
- Development and application of a viscous-flow model.
- Integration of high-resolution seismic models and mineral physics data.
Main Results:
- Inference of a high effective viscosity region near 2,000 km depth.
- Observed re-organization of mantle flow from short to long horizontal scales.
- Suppression of flow-induced deformation and convective mixing in the deep mantle.
- Prediction of compositional and thermal heterogeneity consistent with seismic velocity anomalies.
Conclusions:
- The deep mantle exhibits a high-viscosity layer influencing flow patterns.
- Mega-plumes beneath the Pacific and Africa are buoyant and actively upwelling structures.
- Mantle convection models constrained by geophysical data improve our understanding of deep Earth processes.
More Related Videos
Related Concept Videos
03:05Acid Strength and Molecular Structure
Binary Acids and Bases
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with increasing...
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with increasing...
01:20Elastic Strain Energy for Shearing Stresses
As discussed in previous lessons, strain energy in a material is the energy stored when it is elastically deformed, a concept crucial in materials science and mechanical engineering. This energy results from the internal work done against the cohesive forces within the material. When a material undergoes shearing stress and corresponding shearing strain, the strain energy density, which is the energy stored per unit volume, is calculated. Within the elastic limit, where the stress is...
01:28Transition Zone
The transition zone in concrete is a critical area where aggregate meets cement paste, marked by a distinct porosity and weakness compared to the surrounding material. The adhesion around the aggregates is primarily due to Van Der Waals forces. The voids within this zone influence its robustness; initially, it is less durable than the surrounding bulk mortar due to larger voids. Initially, when concrete is compacted, a higher water-cement ratio near the aggregates leads to the formation of...
01:18Deep Sea Microbial Ecology
The deep ocean and its underlying sediments represent vast, largely unexplored microbial habitats that extend far beyond the sunlit photic zone. The photic (euphotic) zone typically spans the upper ~100–200 meters of pelagic waters in the open ocean, but its depth varies geographically and seasonally, where sufficient light supports photosynthetic life. Below this lies the deep sea, spanning roughly 1000–6000 meters (bathypelagic to abyssal zones), with deeper hadal trenches extending beyond...