Glacio-Hydro Isostasy

Synonyms

Eustatic sea level; Glacial rebound; Postglacial sea level

Definition

Glacio-hydro isostasy refers to the earth’s response to changes in surface ice and water loading during glacial cycles. During the growth of an ice sheet, the crust is loaded in the areas of glaciation and the crust beneath and near the ice sheet subsides. During the decay phase of an ice sheet, the crust is unloaded and rebounds. This is the glacio-isostasy component. But as water is extracted from, or added into, the oceans during ice growth and decay, the oceanic crust also responds to the changing water load. This response is called the hydro isostasy.

Introduction

The glacio-hydro isostatic effect is manifested in geological, geophysical, and geodetic observations. It is seen in the geological record as a complex spatial and temporal pattern of raised shorelines (Figure 1) in areas of former glaciation (primarily the glacio-isostatic signal) as well as along coastlines far from the former ice margins...