  The continental plates of Earth are known to drift over a geophysical
timescale, and their interactions have lead to some of the most spectacular
geoformations of our planet while also causing natural disasters such as
earthquakes and volcanic activity. Understanding the dynamics of interacting
continental plates is thus significant. In this work, we present a fluid
mechanical investigation of the plate motion, interaction, and dynamics.
Through numerical experiments, we examine the coupling between a convective
fluid and plates floating on top of it. With physical modeling, we show the
coupling is both mechanical and thermal, leading to the thermal blanket effect:
the floating plate is not only transported by the fluid flow beneath, it also
prevents the heat from leaving the fluid, leading to a convective flow that
further affects the plate motion. By adding several plates to such a coupled
fluid-structure interaction, we also investigate how floating plates interact
with each other and show that, under proper conditions, small plates can
converge into a supercontinent.
