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Updated: Jul 15, 2026
06:55
Kinematic History of a Salient-recess Junction Explored through a Combined Approach of Field Data and Analog Sandbox Modeling
Published on: August 5, 2016
Seismological support for the metastable superplume model, sharp features, and phase changes within the lower mantle
Daoyuan Sun1, Eh Tan, Don Helmberger
1Seismological Laboratory, 252-21, California Institute of Technology, Pasadena, CA 91125, USA.
Summary
A new thermal-chemical convection model explains the African Superplume
Area of Science:
- Geophysics
- Seismology
- Earth Sciences
Background:
- The African Superplume's structure and dynamics remain debated.
- Existing models struggle to reconcile seismic observations with thermal-chemical convection.
Purpose of the Study:
- To develop and test a hybrid geophysical model for the African Superplume.
- To map thermal and chemical variations to seismic velocities.
- To explain seismic observations using a novel convection model.
Main Methods:
- Developed a metastable thermal-chemical convection model.
- Mapped temperature and chemistry to P and S wave velocities.
- Generated synthetic seismograms for a 2D hybrid model.
- Compared synthetic data with observed seismic phases (P, S, PKP, SKS).
Main Results:
- The hybrid model successfully explains seismic velocity anticorrelations.
- The model accounts for the sharpness and magnitude of SKS travel time delays.
- Evidence for a D" triplication beneath the superplume's down-welling region was found.
Conclusions:
- The metastable thermal-chemical convection model provides a robust explanation for the African Superplume.
- Seismic data supports the hybrid model's predictions of internal dynamics and a potential phase change.
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