Explained: Natural Whirlpools and where to find them

Natural whirlpools occur in several places across the world. Some are more notable than others. Let's explore a couple of them and discuss what they are.

What is a whirlpool?

Whirlpools are when a body of water rotates when meeting opposing currents or when currents hit an obstacle. You probably see a whirlpool every day without realising it. when you fill a bath or sink with water and pull the plug, a whirlpool is created by the current being sucked down the drain. When whirlpools occur in rivers or the sea, they are referred to as a maelstrom. Poet Edgar Allan Poe is credited for being the first person to introduce the world 'maelstrom' into the English language in his 1841 short story 'A Descent into the maelstrom'.

When a whirlpool or maelstrom produce a downdraft (like in your plughole) this is called a vortex. Let's take a look at some of the notable whirlpools across the world.

Maelstrom of Saltstraumen

Located 20 miles (20km) from Bodo, Norway, close to the arctic circle, the Maelstrom of Saltstraumen is the strongest maelstrom in the world. As with extreme tidal ranges, this maelstrom us caused by a narrow strait that funnels water through four times a day. During a maelstrom at Saltstraumen, some 400 million cubic metres of water pass through the strait. The maelstrom is caused chiefly by the 2-mile (3km) channel which connects Saltfjord with Skjerstandford, forcing the water through with changes in the tide.

During a high tide, the Maelstrom of Saltstraumen is aerated with oxygen, changing the colour to a creamy white and reaches speeds of 25mph (40kph). These conditions make navigation hazardous and limit shipping during a maelstrom event.

Moskstraumen Maelstrom

The Moskstraumen maelstrom is unique in that it occurs in the open sea in the Lofoten Islands off the coast of Norway. Unline the Maelstrom of Saltstraumen, the Moskstraumen is caused by the topography of the seabed, combined with a semi-diurnal tide (read more about tide types). This is then amplified by the shallow ridge between the islands Moskenesøya and Værøy.

As the second strongest maelstrom in the world, it reaches speeds of 20mph (32kph) and the vortex is known to reach the seabed, which makes it particularly hazardous.