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A synoptic view of mantle plume shapes enabled by virtual reality
  • Qianyi Lu,
  • Maxwell L Rudolph
Qianyi Lu
University of California, Davis

Corresponding Author:[email protected]

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Maxwell L Rudolph
University of California, Davis
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Abstract

The shapes of mantle plumes are sensitive to mantle viscosity, density structure, and flow patterns. Increasingly, global tomographic models reveal broad plume conduits in the lower mantle and highly-tilting conduits in the mid and upper mantle. Previous studies mostly relied on 2D slices to analyze plume shapes, but fully investigating the complexity of 3D plume structures requires more effective visualization methods. Here, we use immersive virtual reality (VR) headsets to visualize the full-waveform global tomographic models SEMUCB-WM1 and GLAD-M25 (VS). We develop criteria for the identification of plume conduits based on the relationship between the plume excess temperature and the VS anomaly (∂VS). We are able to trace 20 major plume conduits, measure the offsets of the conduits in azimuth and distance with respect to the hotspots, calculate the tilt angle, and evaluate the ∂VS along all traced conduits. We compare our traced conduits with the conduits predicted by global mantle convection models and vertical conduits. The wavespeed variations along conduits traced from each tomographic model are slower than modeled or vertical conduits, regardless of which tomographic model they are evaluated in. The shapes of traced conduits tend to differ greatly from modeled conduits. Plume ponding and the emergence of secondary plumes, which could result from a combination of different plume compositions, phase transitions, small-scale convection, and variations in viscosity and density of the ambient mantle, can contribute to the complex observed plume shapes.
Jun 2024Published in Geochemistry, Geophysics, Geosystems volume 25 issue 6. 10.1029/2024GC011517