1. n. [Geology]

Global sea level variations. Changes in sea level can result from movement of tectonic plates altering the volume of ocean basins, or when changes in climate affect the volume of water stored in glaciers and in polar icecaps. Eustasy affects positions of shorelines and processes of sedimentation, so interpretation of eustasy is an important aspect of sequence stratigraphy.

See: accommodation,  basin,  hiatus,  isostasy,  Milankovitch cycles,  plate tectonics,  regression,  sequence stratigraphy,  systems tract,  transgression