Changes in hydrologic loads (mass transport) produces significant surface deformationand the mass changes associated with continental hydrology (including ice melting) featureinterannual variations and long-term trends that may be mistaken for components of a tectonicsignal. Mass variations also induce stress changes within the solid Earth, which may interacwith tectonic loading to inflyence earthguake occurrence, although some hydrologica changescause stress changes too small to be important, l willshow examples from Alaska and elsewhereof the impacts of loading deformation and its contribution to earthguakes stress transfer