Eyjafjallajökull (Icelandic: [ˈeiːjaˌfjatl̥aˌjœːkʏtl̥] (listen) EY-ya-FYA-htla-YUH-kuhtl; English: Island Mountain Glacier)[2] 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 with a summit elevation of 1,651 metres (5,417 ft). The volcano has erupted relatively frequently since the last glacial period, most recently in 2010.[3][4]

Eyjafjallajokull Gigjokull in ash
Gígjökull, Eyjafjallajökull's largest outlet glacier covered in volcanic ash
Highest point
Elevation1,651 m (5,417 ft)
Coordinates63°37′12″N 19°36′48″W / 63.62000°N 19.61333°WCoordinates: 63°37′12″N 19°36′48″W / 63.62000°N 19.61333°W[1]
Eyjafjallajökull is located in Iceland
LocationSuðurland, Iceland
Parent range?
Mountain typeStratovolcano
Volcanic arc/beltEast Volcanic Zone
Last eruptionMarch to June 2010
Iceland volcano april 4 2010
North view of (from left to right) Mýrdalsjökull, Fimmvörðuháls and Eyjafjallajökull on 4 April 2010, taken from an altitude of 10,000 metres (32,800 ft)


Eyjafjallajökull consists of a volcano completely covered by an ice cap. The ice cap covers an area of about 100 square kilometres (39 sq mi), feeding many outlet glaciers. The main outlet glaciers are to the north: Gígjökull, flowing into Lónið, and Steinholtsjökull, flowing into Steinholtslón.[5] In 1967, there was a massive landslide on the Steinholtsjökull glacial tongue. On 16 January 1967 at 13:47:55 there was an explosion on the glacier. It can be timed because the seismometers at Kirkjubæjarklaustur monitored the movement. When about 15,000,000 cubic metres (530,000,000 cubic feet) of material hit the glacier a massive amount of air, ice, and water began to move out from under the glacier into the lagoon at the foot of the glacier.[5]

The mountain itself, a stratovolcano, stands 1,651 metres (5,417 ft) at its highest point, and has a crater 3–4 kilometres (1.9–2.5 mi) in diameter, open to the north. The crater rim has three main peaks (clockwise from the north-east): Guðnasteinn, 1,500 metres (4,900 ft); Hámundur, 1,651 metres (5,417 ft); and Guðnasteinn, 1,497 metres (4,911 ft). The south face of the mountain was once part of Iceland's coastline, from which, over thousands of years, the sea has retreated some 5 kilometres (3 mi). The former coastline now consists of sheer cliffs with many waterfalls, of which the best known is Skógafoss. In strong winds, the water of the smaller falls can even be blown up the mountain. The area between the mountain and the present coast is a relatively flat strand, 2 to 5 km (1 to 3 miles) wide, called Eyjafjöll.

Eyjafjallajökull Aerial Panorama
Eyjafjallajökull Aerial Panorama; taken from its south in June 2017


L'Eyjafjallajökull sous les aurores boréales
The Eyjafjallajökull and the aurora.

The name means "glacier" (or more properly here "ice cap") of the Eyjafjöll. The word jökull, meaning glacier or ice cap, is a cognate with the Middle English word ikel surviving in the -icle of English icicle.

Eyjafjöll is the name given to the southern side of the volcanic massif together with the small mountains which form the foot of the volcano.

The name Eyjafjöll is made up of the words eyja (genitive plural of ey, meaning eyot or island), and the plural word fjöll, meaning fells or mountains, and together literally means: "the mountains of the islands". The name probably refers to the close-by archipelago of Vestmannaeyjar.

The word fjalla is the genitive plural of fjöll, and so Eyjafjalla is the genitive form of Eyjafjöll and means: "of the Eyjafjöll". A literal part-by-part translation of Eyjafjallajökull would thus be "Islands' Mountains' ice cap".

Eyjafjallajökull is sometimes referred to by the numeronym "E15".[6]


Volcanic system of Iceland-Map-en
Active volcanic areas and systems in Iceland

The stratovolcano, whose vents follow an east-west trend, is composed of basalt to andesite lavas. Most of its historical eruptions have been explosive.[7] However, fissure vents occur on both (mainly the west) sides of the volcano.[7]

The volcano is fed by a magma chamber under the mountain, which in turn derives from the tectonic divergence of the Mid-Atlantic Ridge. It is part of a chain of volcanoes stretching across Iceland. Its nearest active neighbours are Katla, to the northeast, and Eldfell, on Heimaey, to the southwest. The volcano is thought to be related to Katla geologically, in that eruptions of Eyjafjallajökull have generally been followed by eruptions of Katla.

Iceland Eyjafjallajökull from Sólheimajökull
Eyjafjallajökull in March 2006, viewed from a recreation area on the Sólheimajökull, a glacier on the Katla volcano

Eyjafjallajökull erupted in the years 920 and 1612.

1821 to 1823 eruptions

Some damage was caused by a minor eruption in 1821.[8] Notably, the ash released from the eruption contained a large fraction of fluoride, which in high doses may harm the bone structure of cattle, horses, sheep and humans. The eruption also caused some small and medium glacier runs and flooding in nearby rivers Markarfljót and Holtsá. The eruptive phase started on 19 and 20 December 1821 by a series of explosive eruptions and continued over the next several days. The sources describe heavy ash fall in the area around the volcano, especially to the south and west.[8]

After that event the sequence of eruptions continued on a more subdued level until June 1822.

From the end of June until the beginning of August 1822, another sequence of explosive eruptions followed. The eruption columns were shot to considerable heights, with ashfall in both the far north of the country, in Eyjafjörður, and in the southwest, on the peninsula of Seltjarnarnes near Reykjavík.

The period from August to December 1822 seemed quieter, but farmers attributed the death of cattle and sheep in the Eyjafjörður area to poisoning from this eruption, which modern analysis identifies as fluoride poisoning. Some small glacier runs occurred in the river Holtsá. A bigger one flooded the plains near the river Markarfljót. (The sources do not indicate the exact date.).[9]

In 1823, some men went hiking up on Eyjafjallajökull to inspect the craters. They discovered a fissure vent near the summit caldera a bit to the west of Guðnasteinn.

In early 1823, the nearby volcano Katla under the Mýrdalsjökull ice cap erupted and at the same time steam columns were seen on the summit of Eyjafjallajökull.

The ash of Eyjafjallajökull’s 1821 eruptions is to be found all over the south of Iceland. It is dark grey in colour, small-grained and intermediate rock containing about 28–40% silicon dioxide.

2010 eruptions

Eyjafjallajökull Glacier - 29.8.09
A photo of Eyjafjallajökull taken from Route 1 in August 2009

On 26 February 2010, unusual seismic activity along with rapid expansion of the Earth's crust was registered by the Meteorological Institute of Iceland.[10] This gave geophysicists evidence that magma was pouring from underneath the crust into the magma chamber of the Eyjafjallajökull volcano and that pressure stemming from the process caused the huge crustal displacement at Þorvaldseyri farm.[11] In March 2010, almost three thousand small earthquakes were detected near the volcano, all having a depth of 7–10 kilometres (4.3–6.2 mi).[12] The seismic activity continued to increase and from 3–5 March, close to 3,000 earthquakes were measured at the epicenter of the volcano.

The eruption is thought to have begun on 20 March 2010, about 8 kilometres (5 mi) east of the top crater of the volcano, on Fimmvörðuháls, the high neck between Eyjafjallajökull and the neighbouring icecap, Mýrdalsjökull. This first eruption, in the form of a fissure vent, did not occur under the glacier and was smaller in scale than had been expected by some geologists. The fissure opened on the north side of Fimmvörðuháls, directly across the popular hiking trail between Skógar, south of the pass, and Þórsmörk, immediately to the north.

Fimmvorduhals 2010 03 27 dawn
The eruption on 27 March 2010
Eyjafjallajökull crater 2013
The crater three years post eruption in March 2013
Eyjafjallajökull, Suðurland, Islandia, 2014-08-17, DD 111
Eyjafjallajökull seen from the sea in summer 2014.

On 14 April 2010 Eyjafjallajökull resumed erupting after a brief pause, this time from the top crater in the centre of the glacier, causing jökulhlaup (meltwater floods) to rush down the nearby rivers, and requiring 800 people to be evacuated.[4] This eruption was explosive, due to meltwater getting into the volcanic vent. It was estimated to be ten to twenty times larger than the previous one in Fimmvörðuháls. This second eruption threw volcanic ash several kilometres up in the atmosphere, which led to air travel disruption in northwest Europe for six days from 15 April to 21 April 2010 and again, in May 2010, including the closure of airspace over many parts of Europe.[13] The eruptions also created electrical storms.[14] On 23 May 2010, the London Volcanic Ash Advisory Centre declared the eruption to have stopped, but stated that they were continuing to monitor the volcano.[15] The volcano continued to have several earthquakes daily, with volcanologists watching the volcano closely.[16] As of August 2010, Eyjafjallajökull was considered dormant.[17] Infrasound sensors have been installed around Eyjafjallajökull to monitor for future eruptions.[18]

Relationship to Katla

Eyjafjallajökull en Katla
Cross section through Eyjafjöll and Katla

Eyjafjallajökull lies 25 km (16 mi) west of another subglacial volcano, Katla, under the Mýrdalsjökull ice cap, which is much more active and known for its powerful subglacial eruptions and its large magma chamber.[19] Each of the eruptions of Eyjafjallajökull in 920, 1612, and 1821–1823 has preceded an eruption of Katla.[20] Katla did not display any unusual activity (such as expansion of the crust or seismic activity) during the 2010 eruptions of Eyjafjallajökull, though geologists have been concerned about the general instability of Katla since 1999. Some geophysicists in Iceland believe that the Eyjafjallajökull eruption may trigger an eruption of Katla, which would cause major flooding due to melting of glacial ice and send up massive plumes of ash.[20][21] On 20 April 2010, Icelandic President Ólafur Grímsson said "the time for Katla to erupt is coming close...we [Iceland] have prepared...it is high time for European governments and airline authorities all over the world to start planning for the eventual Katla eruption".[22]

Volcanologists continue to monitor Katla, aware that any eruption from Katla following an eruption from Eyjafjallajökull has historically occurred within months of an Eyjafjallajökull eruption. The Icelandic Meteorological Office updates its website with reports of quakes at both Eyjafjallajökull and Katla.[16] On 8 July 2011 there was a jökulhlaup that destroyed a bridge on the Ring Road and caused cracks to appear on Katla's glacier.[23]


James May drove a Toyota Hilux up the volcano in a 2010 episode of the television show Top Gear. May reached the summit mere hours before the eruption began, although he and his camera crew had left the volcano by that time.

Eyjafjallajökull was featured in the 2013 film The Secret Life of Walter Mitty.

Eyjafjallajökull is featured as one of the natural wonders in the computer game Civilization VI.

Eyjafjallajökull is mentioned in the JJ Doom song "Guv'nor", from the 2012 album Key to the Kuffs.

Emo/Indie band The World Is a Beautiful Place & I Am No Longer Afraid to Die reference Eyjafjallajökull in the song "Eyjafjallajökull Dance" from their EP, "Formlessness", released in 2010 [1]

See also


  1. ^ "Eyjafjallajökull". Peakbagger.com. Retrieved 2015-11-24.
  2. ^ "Eyjafjallajokull | glacier, Iceland | Britannica.com". Global.britannica.com. Retrieved 2015-11-24.
  3. ^ Thordarson, T.; Larsen, G. (2007). "Increasing signs of activity at Eyjafjallajökull in Iceland: Eruptions". Journal of Geodynamics. 43: 118–152. CiteSeerX doi:10.1016/j.jog.2006.09.005. Archived from the original on 2010-04-19. Retrieved 2010-04-17.
  4. ^ a b "Iceland's volcanic ash halts flights in northern Europe". BBC News. 15 April 2010. Retrieved 15 April 2010.
  5. ^ a b "Eyjafjallajokull – Iceland On The Web". Iceland.vefur.is. Retrieved 2015-11-24.
  6. ^ Schleicher, N.; Kramar, U.; Dietze, V.; Kaminski, U.; Norra, S. (2012). "Geochemical characterization of single atmospheric particles from the Eyjafjallajökull volcano eruption event collected at ground-based sampling sites in Germany". Atmospheric Environment. 48: 113. doi:10.1016/j.atmosenv.2011.05.034.
  7. ^ a b "Eyjafjallajökull". Global Volcanism Program. Smithsonian Institution. Retrieved 2010-04-18.
  8. ^ a b Larsen, G. (1999). Gosið í Eyjafjallajökli 1821–1823 [The eruption of the Eyjafjallajökull volcano in 1821–1823] (PDF) (in Icelandic). Reykjavík: Science Institute. p. 13. Research Report RH-28-99. Archived from the original (PDF) on 2010-11-22.
  9. ^ ""Last Eyjafjallajökull Eruption Lasted Two Years", Iceland Review". Icelandreview.com. Retrieved 2010-04-18.
  10. ^ "Fasteignaskrá measurement tools". Skra.is. Retrieved 2015-11-24.
  11. ^ Morgublaðið (26.02.2010) "Innskot undir Eyjafjallajökli". Morgunblaðið.
  12. ^ Veðurstofa Íslands (5 March 2010) "Jarðskjálftahrina undir Eyjafjallajökli". Veðurstofa Ísland (The Meteorological Institute of Iceland).
  13. ^ "Ash chaos: Row grows over airspace shutdown costs". BBC News. 2010-04-22. Retrieved 2015-11-24.
  14. ^ "'Dirty thunderstorm': Lightning in a volcano".
  15. ^ "Met Office: Volcanic Ash Advisory Centres". Metoffice.gov.uk. Retrieved 2015-11-24.
  16. ^ a b "Iceland Meteorological office – Earthquakes Mýrdalsjökull, Iceland". En.vedur.is. Retrieved 2013-03-26.
  17. ^ "Iceland volcano 'pauses'". Metoffice.gov.uk. Archived from the original on 2011-07-14. Retrieved 2010-07-12.
  18. ^ Hall, Shannon (November 15, 2018). "World's first automated volcano forecast predicts Mount Etna's eruptions". Nature. Working with the Icelandic Meteorological Office in Reykjavik, the scientists have installed five sensor arrays across the island to monitor infrasound waves from multiple volcanoes. Among them is the infamous Eyjafjallajökull, whose last eruption, in 2010, shut down air traffic across northwestern Europe for weeks.
  19. ^ "Green.view: Back into the clouds". The Economist. 2010-04-16. Retrieved 2010-04-22.
  20. ^ a b Roger Boyes (21 March 2010). "Iceland prepares for second, more devastating volcanic eruption". London: TimesOnline. Retrieved 21 March 2010.
  21. ^ Kastljósið 22.3.2010, Sjónvarpið, "Viðtal við Dr. Pál Einarsson, jarðeðlisfræðing"
  22. ^ "Newsnight – Olafur Grimsson: Eruption is only 'small rehearsal'". BBC News. 2010-04-20. Retrieved 2015-11-24.
  23. ^ "Weekly Reports". Katla. Smithsonian Global Volcanism Program.

External links

Videos and webcams
Geological articles
Aviation ash forecasts
2010 Japanese motorcycle Grand Prix

The 2010 Japanese motorcycle Grand Prix was the fourteenth round of the 2010 Grand Prix motorcycle racing season. It took place on the weekend of 1–3 October 2010 at the Twin Ring Motegi, located in Motegi, Japan. It was originally planned to take place on the weekend of April 23–25, but due to disrupted air travel caused by the 2010 eruption of Eyjafjallajökull it was postponed as it was difficult for team personnel and equipment to get there.

2010 eruptions of Eyjafjallajökull

The 2010 eruptions of Eyjafjallajökull were volcanic events at Eyjafjallajökull in Iceland which, although relatively small for volcanic eruptions, caused enormous disruption to air travel across western and northern Europe over an initial period of six days in April 2010. Additional localised disruption continued into May 2010. The eruption was declared officially over in October 2010, when snow on the glacier did not melt. From 14–20 April, ash from the volcanic eruption covered large areas of Northern Europe. About 20 countries closed their airspace to commercial jet traffic and it affected approximately 10 million travellers.Seismic activity started at the end of 2009 and gradually increased in intensity until on 20 March 2010, a small eruption started rated as a 1 on the volcanic explosivity index.Beginning on 14 April 2010, the eruption entered a second phase and created an ash cloud that led to the closure of most of the European IFR airspace from 15 until 20 April 2010. Consequently, a very high proportion of flights within, to, and from Europe were cancelled, creating the highest level of air travel disruption since the Second World War. The second phase resulted in an estimated 250 million cubic metres (330,000,000 cu yd) (0.25 km3) of ejected tephra and an ash plume that rose to a height around 9 km (5.6 mi), which rates the explosive power of the eruption as a 4 on the volcanic explosivity index. By 21 May 2010, the second eruption phase had subsided to the point that no further lava or ash was being produced.

By the evening of 6 June 2010, a small, new crater had opened up on the west side of the main crater. Explosive activity from this new crater was observed with emission of small quantities of ash. Seismic data showed that the frequency and intensity of earth tremors still exceeded the levels observed before the eruption, therefore scientists at the Icelandic Meteorological Office (IMO) and the Institute of Earth Sciences, University of Iceland (IES) continued to monitor the volcano.

In October 2010, Ármann Höskuldsson, a scientist at the University of Iceland Institute of Earth Sciences, stated that the eruption was officially over, although the area was still geothermally active and might erupt again.

Air travel disruption after the 2010 Eyjafjallajökull eruption

In response to concerns that volcanic ash ejected during the 2010 eruptions of Eyjafjallajökull in Iceland would damage aircraft engines, the controlled airspace of many European countries was closed to instrument flight rules traffic, resulting in the largest air-traffic shut-down since World War II. The closures caused millions of passengers to be stranded not only in Europe, but across the world. With large parts of European airspace closed to air traffic, many more countries were affected as flights to, from, and over Europe were cancelled.

After an initial uninterrupted shutdown over much of northern Europe from 15 to 23 April, airspace was closed intermittently in different parts of Europe in the following weeks, as the path of the ash cloud was tracked. The ash cloud caused further disruptions to air travel operations in Ireland, Northern Ireland, and Scotland on 4 and 5 May and in Spain, Portugal, northern Italy, Austria, and southern Germany on 9 May. Irish and UK airspace closed again on 16 May and reopened on 17 May.The eruption occurred beneath glacial ice. The cold water from the melting ice chilled the lava quickly, causing it to fragment into very small particles of glass (silica) and ash, which were carried into the eruption plume. The extremely fine ash particles and the large volume of steam from the glacial meltwater sent an ash plume hazardous to aircraft rapidly high into the upper atmosphere. The presence and location of the plume depended upon the state of the eruption and the winds. The large amount of glacial meltwater flowing into the eruption vent made this eruption so explosive that it injected its ash plume directly into the jet stream, which was unusually stable and south-easterly. The ash was then carried over Europe into some of the busiest airspace in the world.

The International Air Transport Association (IATA) estimated that the airline industry worldwide would lose €148 million (US$200 million, GB£130 million) a day during the disruption. IATA stated that the total loss for the airline industry was around US$1.7 billion (£1.1 billion, €1.3 billion). The Airport Operators Association (AOA) estimated that airports lost £80 million over the six-and-a-half days. Over 95,000 flights had been cancelled all across Europe during the six-day travel ban, with later figures suggesting 107,000 flights cancelled during an 8-day period, accounting for 48% of total air traffic and roughly 10 million passengers.

Disaster tourism

Disaster tourism has been defined as the practice of visiting locations at which an environmental disaster, either natural or man-made, has occurred. Although a variety of disasters are the subject of subsequent disaster tourism, the most common disaster tourist sites are the areas surrounding volcanic eruptions. Opinions on the morality and impact of disaster tourism are divided. Advocates of disaster tourism often claim that the practice raises awareness of the event, stimulates the local economy, and educates the public about the local culture, while critics claim that the practice is exploitative, profits on loss, and often mischaracterizes the events in question.

Effects of the April 2010 Eyjafjallajökull eruption

The eruption of the Eyjafjallajökull volcano in Iceland on 20th March 2010 affected the economic, political and cultural activities in Europe and across the world.

There was an extensive air travel disruption caused by the closure of airspace over many countries affecting the travel arrangements of hundreds of thousands of people in Europe and elsewhere. Sporting, entertainment and many other events were cancelled, delayed or disrupted when individuals or teams were unable to travel to their destination.

The state funeral of Lech Kaczyński and Maria Kaczyńska on 18 April 2010 was affected as some national leaders were unable to attend, including Barack Obama, Stephen Harper, Angela Merkel, and Nicolas Sarkozy.

Eurasian Plate

The Eurasian Plate is a tectonic plate which includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent, and the area east of the Chersky Range in East Siberia. It also includes oceanic crust extending westward to the Mid-Atlantic Ridge and northward to the Gakkel Ridge.

The eastern side is a boundary with the North American Plate to the north and a boundary with the Philippine Sea Plate to the south and possibly with the Okhotsk Plate and the Amurian Plate. The southerly side is a boundary with the African Plate to the west, the Arabian Plate in the middle and the Indo-Australian Plate to the east. The westerly side is a divergent boundary with the North American Plate forming the northernmost part of the Mid-Atlantic Ridge, which is straddled by Iceland. All of the volcanic eruptions in Iceland, such as the 1973 eruption of Eldfell, the 1783 eruption of Laki, and the 2010 eruption of Eyjafjallajökull, are caused by the North American and the Eurasian plates moving apart, which is a result of divergent plate boundary forces.

The geodynamics of central Asia is dominated by the interaction between the Eurasian and Indian Plates. In this area, many subplates or crust blocks have been recognized, which form the Central Asian and the East Asian transit zones.

Eyjafjallajökull (film)

Eyjafjallajökull is a 2013 French comedy film directed by Alexandre Coffre.

Ferry flying

Ferry flying refers to delivery flights for the purpose of returning an aircraft to base, delivering a new aircraft from its place of manufacture to its customer, moving an aircraft from one base of operations to another or moving an aircraft to or from a maintenance facility for repairs, overhaul or other work.An aircraft may need to be moved without passengers from one airport to another at the end of that day's operations in order to satisfy the next day's timetable – these are known as positioning flights, although strictly speaking these are still a type of ferry flight. Positioning flights may also be necessary following a major weather event or other similar disruption which causes multiple cancellations across an airline's network resulting in many aircraft and crew being 'out of position' for normal operations; the 2010 eruptions of Eyjafjallajökull or the mass evacuation of US airspace following the 9/11 attacks being significant examples of this. Some airlines permit fare-paying passengers to travel on positioning flights.


Fimmvörðuháls (Icelandic pronunciation: [ˈfɪmˌvœrðʏˌhauls] (listen); "five cairns pass") is the area between the glaciers Eyjafjallajökull and Mýrdalsjökull in southern Iceland. The route between Skógar and Thórsmörk goes through this pass and is one of the most popular walking routes in Iceland, despite being 22 kilometres (14 mi) long and involving 1,000 metres (3,300 ft) of climbing. At Fimmvörðuháls, there is a comfortable, modern mountain hut owned by Útivist, one of the Icelandic hiking associations. Also nearby is an older, less well-equipped hut called Baldvinsskáli. The route from Skógar is particularly beautiful, as numerous waterfalls are passed along the way. The route is only accessible between mid-June and late-August. On the night of 16 May 1970, three travellers died in the mountain pass in a snowstorm.

It is also possible to combine the Fimmvörðuháls route with the Laugavegur trek between Landmannalaugar and Thórsmörk to make a trip of 4–6 days in length.

Katla (volcano)

Katla (Icelandic pronunciation: [ˈkʰahtla] (listen)) is a large volcano in southern Iceland. It is very active; twenty eruptions have been documented between 930 and 1918, at intervals of 20–90 years. It has not erupted violently for 101 years, although there may have been small eruptions that did not break the ice cover, including ones in 1955, 1999, and 2011.Prior eruptions have had a Volcanic Explosivity Index (VEI) of between 4 and 6 on a scale of 0 to 8. In comparison, the Eyjafjallajökull 2010 eruption had a VEI of 4. Bigger VEI-5 eruptions are comparable to Mount Pinatubo's 1991 eruption, while significantly rarer VEI-6 eruptions would be comparable to Krakatoa's 1883 eruption.

Katla is one of the largest volcanic sources of carbon dioxide (CO2) on Earth, accounting for up to 4% of total global volcanic carbon dioxide emissions.

List of volcanoes in Iceland

This list of volcanoes in Iceland includes 130 active and extinct volcanic mountains, of which 18 have erupted since human settlement of Iceland began circa 900 CE.


Markarfljót is a river in the south of Iceland. It is approximately 100 kilometers long.

The Markarfljót rises in the Rauðafossafjöll massif, east of the volcano Hekla. The main sources for the river are the glaciers Mýrdalsjökull and Eyjafjallajökull. It flows through narrow gorges in the mountainous area between the glaciers Tindfjallajökull and Torfajökull, then spreads in the wide 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 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.

The highest discharge ever measured in the Markarfljót was 2,100 m3/s (74,000 cu ft/s) in 1967, during the Steinholt jökulhlaup.

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.


Mýrdalsjökull (pronounced [ˈmirtalsˌjœːkʏtl] (listen), Icelandic for "(the) mire dale glacier" or "(the) mire valley glacier") is an ice cap in the south of Iceland. It is to the north of Vík í Mýrdal and to the east of the smaller ice cap Eyjafjallajökull. Between these two glaciers is Fimmvörðuháls pass. Its peak reaches 1,493 m (4,898 ft) in height and in 1980 it covered an area of 595 km2 (230 sq mi).

The icecap of the glacier covers an active volcano called Katla. The caldera of the volcano has a diameter of 10 km (6 mi) and the volcano erupts usually every 40–80 years. The last eruption took place in 1918. Scientists are actively monitoring the volcano, particularly after the eruption of nearby Eyjafjallajökull began in April 2010. Since the year 930, 16 eruptions have been documented.

The Eldgjá, a volcanic eruption fissure about 30 km (19 mi) long, which erupted in the year 936, is part of the same volcanic system.

Before the Hringvegur (the main ring road round the island) was built, people feared traversing the plains in front of the volcano because of the frequent jökulhlaups (glacial floods) and the deep rivers to be crossed, although the road is still vulnerable to major events. Especially dangerous was the glacial flood after the eruption of 1918 when the coastline was extended by 5 km (3.1 mi) by laharic flood deposits.

Mýrdalsjökull is an exceedingly wet location, with models suggesting it receives more than 10 metres of precipitation annually.

Rootless cone

A rootless cone, also formerly called a pseudocrater, is a volcanic landform which resembles a true volcanic crater, but differs in that it is not an actual vent from which lava has erupted. They are characterised by the absence of any magma conduit which connects below the surface of a planet.

Rootless cones are formed by steam explosions as flowing hot lava crosses over a wet surface, such as a swamp, a lake, or a pond. The explosive gases break through the lava surface in a manner similar to a phreatic eruption, and the tephra builds up crater-like forms which can appear very similar to real volcanic craters.

Well known examples are found in Iceland like the craters in the lake Mývatn (Skútustaðagígar), the Rauðhólar in the region of the capital city Reykjavík or the Landbrotshólar located in South-Iceland in the Katla UNESCO Global Geopark in the vicinity of Kirkjubæjarklaustur. Rootless cones have also been discovered in the Athabasca Valles region of Mars, where lava flows superheated groundwater in the underlying rocks.Volcanologists witnessed the formation of a rootless cone for the first time in history during a steam explosion in connection with the first eruption of Eyjafjallajökull in March 2010.


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 60 m (197 ft) and is part of the Seljalands River that has its origin in the volcano glacier Eyjafjallajökull. Visitors can walk behind the falls into a small cave.

Subglacial eruption

Subglacial eruptions, those of ice-covered volcanoes, result in the interaction of magma with ice and snow, leading to meltwater formation, jökulhlaups, and lahars. Flooding associated with meltwater is a significant hazard in some volcanic areas, including Iceland, Alaska, and parts of the Andes. Jökulhlaups, glacial outburst floods, have been identified as the most frequently occurring volcanic hazard in Iceland, with major events where peak discharges can reach 10 000 – 100 000 m3/s occurring when there are large eruptions beneath glaciers.

It is important to explore volcano-ice interactions to improve our ability to effectively monitor these events and to undertake hazard assessments. This is particularly relevant given that subglacial eruptions have recently demonstrated their ability to cause widespread impact, with the ash cloud associated with Iceland’s Eyjafjallajökull eruption resulting in significant impacts to aviation across Europe.


Thórsmörk (Icelandic: Þórsmörk, [listen] ) is a mountain ridge in Iceland that was named after the Norse god Thor (Þór). It is situated in the south of Iceland between the glaciers Tindfjallajökull and Eyjafjallajökull. The name "Thórsmörk" properly refers only to the mountain ridge between the rivers Krossá, Þröngá, and Markarfljót, but is sometimes used informally to describe a wider area that includes the region between Thórsmörk and Eyjafjallajökull. Thórsmörk is one of the most popular hiking areas in Iceland.

In the valley, the river Krossá winds between the mountains. The valley is closed in between glaciers, Mýrdalsjökull being at the rear end of the valley. This leads to an especially warm climate, better than in the rest of south Iceland. In the protected valley, green vegetation of moss, fern, birchwood, and other small shrubs are found.

Thórsmörk is popular amongst hikers. Many different tours are possible, from hiking on the glaciers to trekking (i.e., Laugavegur up to Landmannalaugar) or smaller excursions, such as to the canyon Stakkholtsgjá with its waterfall or five small day treks, to the summits of surrounding peaks, with rewarding views, even in bad weather. The Krossá is a cold, fast river coming down from glaciers; a bridge allows pedestrians to cross. Coaches arrive daily from Reykjavík and other towns in Iceland.

Volcanic lightning

Volcanic lightning is a atmospheric electrical discharge caused by a volcanic eruption, rather than from an ordinary thunderstorm. Volcanic eruptions producing lightning can be colloquially referred to as a dirty thunderstorm, but this term technically only refers to ash-rich plumes interacting with weather systems containing ice. Volcanic lightning can occur entirely independently of any meteorological interactions.

The earliest recorded observations of volcanic lightning are from Pliny the Younger, describing the eruption of Mount Vesuvius in 79 AD, “There was a most intense darkness rendered more appalling by the fitful gleam of torches at intervals obscured by the transient blaze of lightning.” The first studies of volcanic lightning were also conducted at Mount Vesuvius by Professor Palmieri who observed the eruptions of 1858, 1861, 1868, and 1872 from the Vesuvius Observatory. These eruptions often included lightning activity.Volcanic lightning arises from the ash, rock fragments, and other ejecta which generate static electricity within the volcanic plume. One study stated that “27-35% of eruptions are accompanied by lightning, assuming one eruption per year per volcano”, and indicated that volcanic lightning has been observed in 212 eruptions from 80 different volcanoes.A famous image of the phenomenon was photographed by Carlos Gutierrez and occurred in Chile above the Chaiten Volcano. It circulated widely on the internet. Another notable image of this phenomenon is "The Power of Nature", taken by Mexican photographer Sergio Tapiro in Colima, Mexico, which won third place (Nature category) in the 2016 World Press Photo Contest. Other instances have been reported above Alaska's Mount Augustine volcano, Iceland's Eyjafjallajökull volcano and Mount Etna in Sicily, Italy.

Volcanology of Iceland

The volcano system in Iceland that started activity on August 17, 2014, and ended on February 27, 2015, is Bárðarbunga.

The volcano in Iceland that erupted in May 2011 is Grímsvötn.

The volcanoes of Iceland include a high concentration of active ones due to Iceland's location on the mid-Atlantic Ridge, a divergent tectonic plate boundary, and its location over a hot spot. The island has 30 active volcanic systems, of which 13 have erupted since the settlement of Iceland in AD 874.Of these 30 active volcanic systems, the most active/volatile is Grímsvötn. Over the past 500 years, Iceland's volcanoes have erupted a third of the total global lava output.The most fatal volcanic eruption of Iceland's history was the so-called Skaftáreldar (fires of Skaftá) in 1783-84. The eruption was in the crater row Lakagígar (craters of Laki) southwest of Vatnajökull glacier. The craters are a part of a larger volcanic system with the subglacial Grímsvötn as a central volcano. Roughly a quarter of the Icelandic nation died because of the eruption. Most died not because of the lava flow or other direct effects of the eruption, but from indirect effects, including changes in climate and illnesses in livestock in the following years caused by the ash and poisonous gases from the eruption. The 1783 eruption in Lakagígar is thought to have erupted the largest quantity of lava from a single eruption in historic times.

The eruption under Eyjafjallajökull ("glacier of Eyjafjöll") in 2010 was notable because the volcanic ash plume disrupted air travel in northern Europe for several weeks; however this volcano is minor in Icelandic terms. In the past, eruptions of Eyjafjallajökull have been followed by eruption of the larger volcano Katla, but after the 2010 eruption no signs of an imminent eruption of Katla were seen.The eruption in May 2011 at Grímsvötn under the Vatnajökull glacier sent thousands of tonnes of ash into the sky in a few days, raising concerns of a repeat of the travel chaos seen across northern Europe.

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