This figure shows a model of a mantle plume in spherical axisymmetric geometry, created using the finite-element model SCAM. The axis of symmetry runs along the center of the plot. Contours are temperature. Colors indicate radial velocity. More intense colors denote higher velocity. Red denotes radial outward flow; blue denotes inward flow.

What is a mantle plume?

In 1971, W. J. Morgan suggested that intraplate volcanism such as the hotspot at Hawaii derives from hot upwelling plumes in the mantle. Our current understanding of the mantle suggests that convection takes the form of subducting plates and upwelling, approximately axisymmetric plumes. According to this model, hotspots are the surface manifestation of mantle plumes. In terms of heat flow, plumes are relatively minor; Davis (1988) and Sleep (1990) used the topography and gravity anomalies associated with hot-spots to estimate that actively upwelling mantle plumes account for about 10% of the total heat loss of the Earth.

Nevertheless, the hotspots are of interest, because they have given us such geological features as Hawaii, Iceland, Yellowstone, etc.

In addition, plumes may be an important mechanism for heat transfer from the interior of Venus.

Some open questions about plumes

Plume modeling at U.C. Davis

We are looking at these and other questions using numerical models of mantle plumes. Recent and ongoing work includes:

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