Answer:
Shear stress, force tending to cause deformation of a material by slippage along a plane or planes parallel to the imposed stress. The resultant shear is of great importance in nature, being intimately related to the downslope movement of earth materials and to earthquakes.
They are doing the transform type of tectonic plate movement. This is a process where the plates move sideways. But they move at a rate of a few inches a year. Did that help you?
Force is (mass × acceleration) measured in Newton
Pressure is the 'force' per unit area measured in Newton/m^2 (pascal)