postglacial

Postglacial describes the period following a major glaciation and the landscapes, climates, and biota that characterize it. The term is used in geology, geography, ecology, and archaeology to refer to the interval after a glacier has retreated, most commonly after the Last Glacial Maximum. In many regions it begins roughly between 19,000 and 11,700 years ago and extends to the present, with regional timing varying by glacial history.

During postglaciation, deglaciation proceeds as ice sheets thin and withdraw, releasing land from ice pressure. Isostatic rebound can raise coastlines and inland areas, while meltwater raises global sea levels. Landscapes often display moraines, outwash plains, kettle lakes, and drumlins, with soils formed from glacial till and lacustrine deposits that are typically immature but rapidly weathered in favorable climates.

Ecological succession follows deglaciation as pioneer species colonize exposed terrain and forests reestablish to replace tundra. Regional climate warming drives shifts in flora and fauna, migrations of species, and changes in fire regimes. Postglacial intervals thus show a mosaic of habitats including wetlands, grasslands, and boreal forests.

Human populations adapt to new landscapes after glaciation. Shorelines and river valleys become resources for hunting, fishing, and later agriculture; landforms influence settlement patterns and land use. The postglacial period also shapes cultural development and resource management through landscape legacies such as peatlands, loess deposits, and nutrient-rich soils.

Regional patterns are especially pronounced in northern latitudes, where ongoing postglacial rebound continues to modify coastlines. The concept also applies to other glaciations in Earth's history. Studying postglacial processes helps illuminate climate change, landscape evolution, and biogeography.