Are there plate tectonics on IO moon of Jupiter?

Answer 1

Io certainly has tectonic features, however, these features do not require plate tectonics to explain their formation. Most importantly Io lacks liquid water on its surface which is a requirement for the initiation of plate tectonics. Under dry conditions (a dry rheology) the base of the crust undergoes shear stress which cause it to delaminate, while under a wet rheology the shear stresses with the addition of H2O cause subduction. Io's mountains are the cause of tidal forces from its orbit around Jupiter and the mountains are caused by faulting and tilting of crustal blocks due to subsidence under extreme loads of volcanic loading. All of these point to a conclusion that there is no plate tectonics active on Io.