fjord Facts For Kids

Fjords form when a glacier—a huge, slow-moving river of ice—flows through a valley and scrapes away rock. The ice cuts the valley into a wide, U-shaped trough and often digs it deeper than the nearby sea. When the glacier melts and the ocean moves in, that deep U-shaped trough fills with seawater and becomes a fjord.

At the mouth of many fjords, a shallow ridge called a sill or shoal remains. This sill forms because the glacier slowed there or left piles of rock called moraines. You can also see hanging valleys where smaller glaciers joined the main one, sometimes making waterfalls along the fjord sides. Some fjords, like Norway’s Sognefjord, reach over a thousand meters deep.

A fjord is a long, narrow arm of the sea that pushes far into the land. It has very steep sides or tall cliffs because huge rivers of ice carved it long ago. You can find fjords in cold places near the Arctic and Antarctic, and in countries like Norway, which has almost 1,200 fjords. These fjords help make Norway’s coastline much longer — about 29,000 km when you include all the twists and turns of fjords.

Fjords are not the same as rias, which are drowned river valleys flooded by rising seas. Fjords come from ice and look deeper and steeper. How did ice do this work?

Water in fjords changes with the seasons. In winter, there is little fresh water from rivers, so cold winds and cooling mix surface and deep water more. In summer, melting snow and rivers add fresh water to the top, making a lighter, brackish layer that flows out toward the sea while saltier water moves in below.

Many fjords have a shallow sill at their mouth. That sill can slow the exchange of deep water, so the bottom stays cold and may not get fresh oxygen often. Tides, winds, and internal waves help mix fjord waters. Some fjords refresh their deep water well, but others with shallow mouths can have poor deep-water renewal and fewer animals down below.

Tiny plants called phytoplankton live in the surface water of fjords and do photosynthesis, like underwater grass. Melting glaciers and rivers bring nutrients that help some phytoplankton grow quickly, causing blooms that feed tiny animals and then bigger animals like fish and birds. These blooms are especially strong in places where meltwater brings fresh nutrients in spring and summer.

But glaciers also send a lot of fine sediment that makes water cloudy and blocks light, so phytoplankton can’t grow as deep. Changes in meltwater from climate shifts may change how many nutrients arrive, and that can affect the whole fjord food web. Would you like to try looking for phytoplankton under a microscope?

Many of the world’s fjords are on the coasts of northern Europe. The west coast of Norway, including Svalbard and the Kola Peninsula, has thousands of fjords. Iceland’s Westfjords and the eastern coast also have many. Scotland’s West Highlands and the Faroe Islands are other nearby fjord regions.

Fjords appear far beyond Europe. Fiordland on New Zealand’s South Island is full of deep inlets. North America’s northwest coast — Alaska, British Columbia, and parts of Washington — has famous fjords like Glacier Bay and Lynn Canal. The northeast coast of Canada and Greenland also have long fjords. South America’s west coast, especially Chile, has channels and fjords too.

Fjord is a word that comes from old Scandinavian languages. In English it usually means a long, steep-sided sea inlet. But in Norway, Sweden, Denmark and Iceland the word can mean other kinds of water too. For example, in eastern Norway some long freshwater lakes are called fjords, like Randsfjorden and Tyrifjorden. That way of naming goes back to Old Norse, the language spoken long ago in northern Europe.

Nearby words also sound similar. In southeast Sweden and parts of Finland people use fjard for small bays. In Denmark a fjord can be a shallow lagoon. In northern Germany the word Föhrde names long, narrow bays. Old Norse also used the word *angr* for inlets, and that old word appears in many place names today.

Some fjords are especially long. In northern Canada you can find very long fiords such as places often named Tanquary Fiord or Greely Fiord that reach about 420 km (260 mi). In the United States, Lynn Canal in Alaska is around 403 km long. Greenland’s Scoresby Sund is about 382 km, and Norway’s Sognefjord reaches around 226 km.

Some fjords are very deep. Skelton Inlet in Antarctica is nearly 1,933 m deep. Norway’s Sognefjord is also over 1,300 m deep, and parts of Chile reach more than 1,200 m. Around some fjords, mountains rise steeply — for example, cliffs near Sognefjord can be as high as about 2,400 m. Which fjord would you like to visit first?