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Updated: Dec 23, 2025
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Kinematic History of a Salient-recess Junction Explored through a Combined Approach of Field Data and Analog Sandbox Modeling
Published on: August 5, 2016
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Seismic evidence for subduction-induced mantle flows underneath Middle America
Hejun Zhu1, Robert J Stern2, Jidong Yang2
1Department of Geosciences, The University of Texas at Dallas, Dallas, TX, USA. hejun.zhu@utdallas.edu.
Nature Communications
|May 1, 2020
Summary
Deep mantle flows beneath Middle America reveal complex poloidal and toroidal patterns influenced by subducting tectonic plates. These seismic anisotropy findings offer new insights into deep Earth dynamics and mineral behavior.
Area of Science:
- Geophysics
- Seismology
- Tectonics
Background:
- Subduction zones drive complex mantle flows, including poloidal and toroidal modes.
- Understanding these deep flows is crucial for geodynamic processes and plate tectonics.
Purpose of the Study:
- To infer deep subduction-induced mantle flows beneath Middle America using a novel 3-D azimuthal anisotropy model.
- To provide depth-dependent seismic anisotropy data for future mantle flow simulations.
Main Methods:
- Full waveform inversion was employed to construct a new 3-D azimuthal anisotropy model.
- Seismic anisotropy data were analyzed to infer mantle flow patterns at various depths.
Main Results:
- Poloidal flow was observed perpendicular to the Middle American Trench at depths <150 km.
- Return flows and escape flows were identified around slabs and through slab windows at 300-450 km depth.
- The Farallon anomaly at 700 km depth showed fast axes suggesting significant stress-induced mineral orientation.
Conclusions:
- The study reveals depth-dependent seismic anisotropy linked to mantle flow dynamics around subduction zones.
- Further research is needed on mineral deformation and elasticity in the transition zone and uppermost lower mantle.
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