Lateral Motion of Mantle Plumes in 3-D Geodynamic Models

Abstract

It has been proposed that hot spot tracks are caused by moving rigid plates above relatively stationary hot spots. However, the fixity of hot spots remains under debate. Here, we perform 3-D very high resolution (<25 km laterally) global mantle convection models with realistic convection vigor to investigate the lateral motion of mantle plumes. We find that the lateral motion of plumes beneath the Pacific plate is statistically similar to that beneath the Indo-Atlantic plates. In the past 80 Ma, the majority (>90%) of plumes move laterally with an average speed of 0–20 mm/year under the no-net-rotation reference frame, and there are a small portion (~10–20%) of plumes whose lateral motion is less than 5 mm/year. The geodynamic modeling results are statistically in a good agreement with the hot spot motions in the last 5 Ma estimated from observation-based kinematic models. Our results suggest a small-to-moderate (0–20 mm/year) lateral motion of most plume-induced hot spots.