Fjords

A fjord is a long, narrow sea inlet bordered by steep cliffs, typically formed by the deepening of a glacially carved valley that was later flooded by seawater. Fjords are created when glaciers erode valleys into a broad, U-shaped profile; as the climate warmed and glaciers retreated, rising sea levels flooded the valley floors. The term is Norwegian, though similar features are known as fiords in some regions.

Fjords occur along high-latitude coastlines and in some subpolar areas. The best known are in Norway, where tens of fjords line the western coast. Fjords also appear in Iceland, Greenland, New Zealand’s Fiordland, Chilean Patagonia, and parts of Canada and Alaska. In places, the spelling fiord is used, particularly in New Zealand and the United Kingdom.

Geographically, fjords are characterized by steep surrounding cliffs and deep water that lies often well below sea level at the valley floor. Many fjords contain a sill at their mouth, created by overlapping glacial deposits, which can limit mixing with open sea water. Water chemistry can range from saltwater to brackish and, in some inlets, freshwater layers dominate toward the interior. Fjords frequently feature waterfalls and dramatic, rugged scenery.

Notable examples include Sognefjord, Norway’s longest, and Geirangerfjord and Nærøyfjord, both UNESCO World Heritage Sites. Milford Sound in New Zealand and the fjords of southern Chile are popular tourist destinations. Fjords support diverse ecosystems and are important for fishing, tourism, and transport in several regions.

Environmental changes, including glacier retreat and changing sediment supply, can alter fjord hydrology and shoreline dynamics, affecting both natural habitats and human activities.