Figure 1. Geodynamic activity and temperature variation: (a) the past: Wilson global cycles; (b) the future: degeneration of the global cycles. The black curve (1) is the average mantle velocity, the red curve (2) is the average temperature of the lower mantle, the blue curve (3) is the average temperature of the upper mantle, and the violet curve (4) is the average temperature of the whole mantle.