There are major glaciated regions of the world that are also seismologically active. Changes in the thickness of ice due to glacier surges, advances, or retreats produce stress changes that may be a significant fraction of the tectonic stress accumulated during an earthquake cycle. The changes in ice loading can affect both the normal and shear stress on a fault with stresses being enhanced or reduced depending on glacier and fault geometry. The stress change has a nearly instantaneous elastic component and a longer time-scale viscoelastic component. Thus I propose that glacier motion can produce geodetically significant horizontal and vertical crustal displacements and can affect strain, strain rate, and the time of occurrence of earthquakes. In regions that are not tectonically active, rapid ice motion can also produce locally significant and geodetically detectable crustal deformations.