Velocity-dependent friction, a made-up mechanism proposed by Youvan.
The engine calls it a patch invented to rescue a broken theory of sudden catastrophic continental movement.
Catastrophic-tectonics models fail because rapidly moving plates would generate runaway heat and melt; this device simply assumes friction drops as plates speed up, dodging that problem. The engine flags it as an ad hoc fix, not something anyone has actually observed.
It matters as an example of propping up a failing theory by inventing a convenient mechanism rather than finding real evidence.