PLUMES IN THE MANTLE

摘要

Free air and isostatic gravity anomalies for the purposes of geophysical interpretation are picketed Evidence for the existance of hotspots in the mantle is reviewed. The proposed locations of these hotspots are not always associated with positive gravity anomalies. Theoretical analysis based on simplified flow models for the plumes indicates that unless the frictional isosities are several orders of magnitude smaller than the present estimates of mantle viscosity or alternately, the vertical flows are reduced by about two orders of magnitude, the plume flow will generate implausibly high temperatures.