A rise in sea level relative to the land. This causes rocks that were just above sea-level to become submerged above the sea, possibly burying them by marine sediments. The opposite is called regression, when there is a relative fall in sea level.
The gradual expansion of a shallow sea, resulting in the progressive submergence of land, as when sea levels rise or land subsides.
The inland migration of shoreline resulting from a rise in sea level.