Advancing and Retreating Coasts

Eustatic Change

A global change in sea level caused by the addition or removal of water from the oceans (e.g., melting ice sheets or thermal expansion).

Isostatic Change

A local change in land level caused by the loading or unloading of ice, sediment, or tectonic forces (e.g., Scotland rising after the last Ice Age).

Sea-Level Change

The combined effect of eustatic and isostatic processes that alters the position of the coastline over time.

Advancing Coastline

A coastline that is moving seaward because sea level is falling or land is rising, exposing new land.

Retreating Coastline

A coastline that is moving landward because sea level is rising or land is sinking, flooding low-lying areas.

Raised Beach

A former beach now found above current sea level, usually caused by isostatic rebound.

Relict Cliff

A cliff that once faced the sea but is now stranded inland as the coastline has advanced.

Fjord

A steep-sided, deep coastal inlet formed by glacial erosion and later flooded by rising sea levels.

Dalmatian Coast

A drowned limestone landscape where parallel ridges and valleys have become chains of islands.

Ria

A submerged river valley created when rising sea levels flood a river's lower course.

Glacio-Isostatic Adjustment

The slow uplift or sinking of land in response to the growth or melting of ice sheets.

Thermal Expansion

The increase in ocean volume when water warms, a major cause of modern sea-level rise.

Submergent Coastline

A coastline where rising sea levels have drowned valleys, creating features such as rias and fjords.

Emergent Coastline

A coastline that has risen relative to the sea, revealing features such as raised beaches and relict cliffs.

Post-Glacial Rebound

The rise of land after ice sheets have melted, reducing the weight pressing down on the crust.