Overview
- The Nature Geoscience paper, led by Yoshinori Miyazaki with collaborators and published this week, integrates multiple disciplines to reinterpret the lowermost mantle.
- LLSVPs beneath Africa and the Pacific, together with thin ULVZ patches at the core–mantle boundary, are identified as unusually dense, hot regions that strongly slow seismic waves.
- The model posits that over billions of years elements such as silicon and magnesium leaked from the core into a basal magma ocean, preventing strong layering and leaving solidified chemical residues.
- The authors suggest these deep reservoirs may help feed volcanic hotspots like Hawaii and Iceland, with some hotspot lava chemistry aligning better with this scenario than alternatives.
- Proposed links to Earth’s cooling, volcanism and atmospheric evolution remain tentative, with the team calling for further seismic, mineral-physics and geochemical tests to verify the chain of processes.