Iceland encyclopedia Waterfall

Dettifoss

Dettifoss is a major waterfall on Jökulsá á Fjöllum in northeast Iceland. It forms part of the Jökulsárgljúfur canyon landscape, where volcanic rock and powerful river erosion meet.

About Dettifoss

River and waterfall sequence

Jökulsá á Fjöllum begins at Vatnajökull and reaches the sea in Öxarfjörður. As it leaves the highlands, it descends through a sequence that includes Selfoss, Dettifoss and Hafragilsfoss. Dettifoss is approximately 45 metres high and 100 metres wide. Below it, the canyon exposes volcanic structures, including a cross-section of a crater's feeder at Sjónnípa.

Sources: Environment Agency of Iceland — Dettifoss and a row of waterfalls ↗

A landscape still changing

The waterfall continues to erode its brink and retreat upstream. Spray carried onto the west bank keeps nearby ground wet, while freezing conditions can produce substantial ice and snow accumulations. This ongoing erosion belongs to a wider landscape marked by catastrophic floods and volcanism. Jökulsárgljúfur became a national park in 1973 and joined Vatnajökull National Park in 2008.

Sources: Vatnajökull National Park — Dettifoss ↗Vatnajökull National Park — Jökulsárgljúfur ↗

Article reviewed 28 September 2026.

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