glacier flood

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glacier flood

Also known as: glacier run, jökulhlaup

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June 29, 2026

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A glacier outburst flood, also known as a jökulhlaup, occurs when water becomes trapped within or behind a glacier. This trapped water can eventually find a way to escape, melting its path and causing a sudden, large release of water. Iceland has experienced some of the most significant jökulhlaups, with one in 1922 releasing a massive volume of water. These floods can happen in many glaciated mountain regions, with some occurring regularly and others unpredictably.1

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glacier
Glacier floods
Glacier outburst floods, or jökulhlaups, can be spectacular or even catastrophic. These happen when drainage within a glacier is blocked by internal plastic flow and water is stored in or behind the glacier. The water eventually finds a narrow path to trickle out.…
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Glacier outburst floods, or jökulhlaups, can be spectacular or even catastrophic. These happen when drainage within a glacier is blocked by internal plastic flow and water is stored in or behind the glacier. The water eventually finds a narrow path to trickle out.…
Read More

ice jam
Ice jams and prehistoric megafloods
Such floods are known as jökulhlaups, an Icelandic term for subglacial lake outbursts. The largest and best-known floods of this type occurred in the Channeled Scabland of the Columbia Plateau region in eastern Washington state. Ice tongues flowing south from the Cordilleran Ice Sheet periodically dammed the Clark Fork River…
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Such floods are known as jökulhlaups, an Icelandic term for subglacial lake outbursts. The largest and best-known floods of this type occurred in the Channeled Scabland of the Columbia Plateau region in eastern Washington state. Ice tongues flowing south from the Cordilleran Ice Sheet periodically dammed the Clark Fork River…
Read More

Pleistocene Epoch
Fluvial environments
Such floods are known as jökulhlaups, an Icelandic term for subglacial lake outbursts. The largest and best-known floods of this type occurred in the Channeled Scabland of the Columbia Plateau region in eastern Washington state. Ice tongues flowing south from the Cordilleran Ice Sheet periodically dammed the Clark Fork River,…
Read More
Such floods are known as jökulhlaups, an Icelandic term for subglacial lake outbursts. The largest and best-known floods of this type occurred in the Channeled Scabland of the Columbia Plateau region in eastern Washington state. Ice tongues flowing south from the Cordilleran Ice Sheet periodically dammed the Clark Fork River,…
Read More

Vatnajökull
…walls, causing catastrophic floods called jökulhlaup (“glacier runs”). During the eruptions of 1934 and 1938, the rate of jökulhlaup discharge reached 65,000 cubic yards (50,000 cubic metres) per second. In the 20th century a jökulhlaup broke out of Vatnajökull roughly every 5 or 10 years.
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…walls, causing catastrophic floods called jökulhlaup (“glacier runs”). During the eruptions of 1934 and 1938, the rate of jökulhlaup discharge reached 65,000 cubic yards (50,000 cubic metres) per second. In the 20th century a jökulhlaup broke out of Vatnajökull roughly every 5 or 10 years.
Read More