However, ice- and water-load variations trigger solid Earth deformations, gravitational and rotational perturbations that give rise to spatially varying sea level changes. This definition implies that the worldвЂ™s ocean basins are similar to a giant bathtub, with fixed borders represented by continents with sharp and steep boundaries. The opposite occurs during interglacial periods, warmer than today, when the retreat of northern and southern hemisphere ice sheets beyond their current size, together with temperature-induced thermal expansion of ocean water, resulted in higher-than-present sea levels.ДЄccording to SuessвЂ™s definition of eustasy, ocean mass variations following ice sheet fluctuations would result in global uniform mean sea level changes.

This refers to the basic concept that, during glaciations, sea level lowstands were caused by storage of water in form of ice sheets on land, as well as by ocean density variations induced by lower global temperatures. In SuessвЂ™s original view, shorelines identified below and above the modern sea level could be directly linked (at the net of tectonic movements) to eustatic sea level during glacial and interglacial periods.

The original definition was introduced by Suess to explain the observation that sea level is characterized by transgression and regression phases that respectively inundate and expose continental shelves. The term вЂeustasyвЂ™ was coined by the Austrian geologist Edward Suess in 1888 (later translated in English in 1906 ) and derives from the ancient Greek words eu, вЂwellвЂ™, and statikos вЂstatic, fixedвЂ™.

Absolute relative acad 2016