Markarfljót () is a

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

in the south of

Iceland Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the regi ...

. It is approximately long and has had in pre-history

jökulhlaup A jökulhlaup ( ) (literally "glacial run") is a type of glacial outburst flood. It is an Icelandic term that has been adopted in glaciological terminology in many languages. It originally referred to the well-known subglacial outburst floo ...

s which would be potentially catastrophic, if a similar sized one was to happen in the future.

Geography

The Markarfljót rises in the Rauðafossafjöll massif, east of the volcano

Hekla Hekla (), or Hecla, is an active stratovolcano in the south of Iceland with a height of . Hekla is one of Iceland's most active volcanoes; over 20 eruptions have occurred in and around the volcano since the year 1210. During the Middle Ages, th ...

and drains the Grænafjall, Framfjall (to the east) and Emstrur, Almenningar (to the west) basins. The main sources for the river are the glaciers

Mýrdalsjökull Mýrdalsjökull (pronounced , Icelandic for "(the) mire dale glacier" or "(the) mire valley glacier") is an ice cap on the top of the Katla volcano in the south of Iceland. It is to the north of the town of Vík í Mýrdal and to the east of ...

(including Sléttjökull, Entujökull, Hrútárökull outlet glaciers and the Goðalandsjökull ice margin) and

Eyjafjallajökull Eyjafjallajökull (; "glacier of (the mountain) Eyjafjöll"), sometimes referred to by the numeronym E15, is one of the smaller ice caps of Iceland, north of Skógar and west of Mýrdalsjökull. The ice cap covers the caldera of a volcano wi ...

(including Steinsholtsjökull, Gígjökull and Eyjafjallajökull outlet glaciers). It flows through narrow gorges in the mountainous area between the glaciers Tindfjallajökull and

Torfajökull Torfajökull ( Icelandic for "Torfi's glacier"; ) is a rhyolitic stratovolcano, with a large caldera (central volcano) capped by a glacier of the same name and associated with a complex of subglacial volcanoes. Torfajökull last erupted in 1477 an ...

(and Kaldaklofsjökull), which are also sources, then spreads in the wide Markarfljótsaurar sandur plains at Iceland's south coast, near Þórsmörk. The Markarfljót takes its course first north, then west of Þórsmörk and finally empties into the

Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

west of Eyjafjallajökull. One of the Markarfljót's tributaries is the river Krossá , flowing through Þórsmörk, which is notorious for sudden changes in its water level. This river is sourced from the Krossárjökull outlet glacier of Mýrdalsjökull.

Discharges

The highest discharges ever measured in the Markarfljót were in 1967, during the Steinholt jökulhlaup and then during the

2010 eruptions of Eyjafjallajökull Between March and June 2010 a series of Volcano, volcanic events at Eyjafjallajökull in Iceland caused Air travel disruption after the 2010 Eyjafjallajökull eruption, enormous disruption to air travel across Western Europe. The disruptions st ...

Risk

There is evidence of at least 10 jokulhlaups down the Markarfljot in the past 7000 years. Prehistoric jökulhlaup discharges have been much higher than recently and completely covered the Markarfljótsaurar outwash plain which means the total river basin of about with a population of over 1000 is at risk from a jökulhlaup of over in size. The tsunami wave hitting the Vestmannaeyjar Islands from such an event has been estimated to be in height and not to cause significant damage off the coast.

Infrastructure

The first bridge over the river was opened in 1934 near Litli Dímon . It is 242 meters long and was at the time the longest bridge in Iceland. A second bridge was built in 1978 at Emstrur . A third bridge was opened in 1992 a few kilometers south of the first bridge. File:Wading on Iceland (2).jpg, Wading the Krossá River. File:Iceland Magic (14788238061).jpg, Markarfljót gorge. File:Islandia, Markarfljót (1981) 03.jpg, Markarfljótsaurar upper flood plain. File:Iceland 2008-05-24 (2551563858).jpg, Markarfljót view from west bank towards

. File:Seljalandsfoss Waterfall - panoramio (3).jpg,

Seljalandsfoss Seljalandsfoss () is a waterfall in Iceland. Seljalandsfoss is located in the South Region in Iceland right by Route 1 and the road that leads to Þórsmörk Road 249. The waterfall drops and is part of the Seljalands River that has its origin ...

water fall from west bank of Markarfljót File:Vestmannaeyjar Markarfljót 2 Iceland.JPG, River mouth with Markarfljótsaurar flood plain and Vestmannaeyjar islands beyond. The snow cover is on the

volcano. File:Markarfljot Iceland Landscape Photography (133563949).jpeg, Lower Markarfljot bridge.

References

Rivers of Iceland Southern Region (Iceland) {{Coord, 63, 57, 5, N, 19, 21, 31, W, display=title, region:IS_type:river_source:GNS-enwiki