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68-628: Bárðarbunga ( Icelandic pronunciation: [ˈpaurðarˌpuŋka] , alternative name Veiðivötn ), is an active and productive stratovolcano located under Vatnajökull in Vatnajökull National Park which is Iceland 's most extensive glacier . The second highest mountain in Iceland, 2,000 metres (6,600 ft) above sea level, Bárðarbunga is also part of the Bárðarbunga-Veiðivötn volcanic system that

136-458: A composite volcano , is a conical volcano built up by many alternating layers ( strata ) of hardened lava and tephra . Unlike shield volcanoes , stratovolcanoes are characterized by a steep profile with a summit crater and explosive eruptions. Some have collapsed summit craters called calderas . The lava flowing from stratovolcanoes typically cools and solidifies before spreading far, due to high viscosity . The magma forming this lava

204-747: A 4-inch thick ash layer can weigh 120-200 pounds and can get twice as heavy when wet. Wet ash also poses a risk to electronics due to its conductive nature. Dense clouds of hot volcanic ash can be expelled due to the collapse of an eruptive column , or laterally due to the partial collapse of a volcanic edifice or lava dome during explosive eruptions . These clouds are known as pyroclastic surges and in addition to ash , they contain hot lava , pumice , rock , and volcanic gas . Pyroclastic surges flow at speeds over 50 mph and are at temperatures between 200 °C – 700 °C. These surges can cause major damage to property and people in their path. Lava flows from stratovolcanoes are generally not

272-479: A fast moving mudflow . Lahars are typically about 60% sediment and 40% water. Depending on the abundance of volcanic debris the lahar can be fluid or thick like concrete. Lahars have the strength and speed to flatten structures and cause great bodily harm, gaining speeds up to dozens of kilometers per hour. In the 1985 eruption of Nevado del Ruiz in Colombia , Pyroclastic surges melted snow and ice atop

340-515: A final intermediate composition . When the magma nears the top surface, it pools in a magma chamber within the crust below the stratovolcano. The processes that trigger the final eruption remain a question for further research. Possible mechanisms include: These internal triggers may be modified by external triggers such as sector collapse , earthquakes , or interactions with groundwater . Some of these triggers operate only under limited conditions. For example, sector collapse (where part of

408-724: A large eruption occurred in 1996, geologists knew well in advance that a glacial burst was imminent. It did not occur until several weeks after the eruption finished, but monitoring ensured that the Icelandic ring road ( Hringvegur ) was closed when the burst occurred. A section of road across the Skeiðará sandur was washed away in the ensuing flood, but no one was hurt. (See also the main article: 1996 eruption of Gjálp The Gjálp fissure vent eruption in 1996 revealed that an interaction may exist between Bárðarbunga and Grímsvötn. A strong earthquake at Bárðarbunga, about magnitude 5,

476-769: A result of intraplate volcanism on oceanic islands far from plate boundaries. Examples are Teide in the Canary Islands , and Pico do Fogo in Cape Verde . Stratovolcanoes in the East African Rift include Ol Doinyo Lengai in Tanzania, and Longonot in Kenya. Subduction zone volcanoes form when hydrous minerals are pulled down into the mantle on the slab. These hydrous minerals, such as chlorite and serpentine , release their water into

544-461: A significant threat to humans or animals because the highly viscous lava moves slowly enough for everyone to evacuate. Most deaths attributed to lava are due to related causes such as explosions and asphyxiation from toxic gas . Lava flows can bury homes and farms in thick volcanic rock which greatly reduces property value. However, not all stratovolcanoes erupt viscous and sticky lava . Nyiragongo , near Lake Kivu in central Africa ,

612-409: A week-long eruption occurred. Volcanic ash from the eruption fell as far away as mainland Europe and caused short-term disruption of airline traffic into Iceland, but again no glacial burst followed the eruption. Harmonic tremors were recorded twice around Grímsvötn on 2 and 3 October 2010, possibly indicating an impending eruption. At the same time, sudden inflation was measured by GPS in

680-531: Is a passive release of gas during periods of dormancy. As per the above examples, while eruptions like Mount Unzen have caused deaths and local damage, the impact of the June 1991 eruption of Mount Pinatubo was seen globally. The eruptive columns reached heights of 40 km and dumped 17 megatons of SO 2 into the lower stratosphere . The aerosols that formed from the sulfur dioxide (SO 2 ), carbon dioxide (CO 2 ), and other gases dispersed around

748-484: Is approximately 190 kilometres (120 mi) long and 25 kilometres (16 mi) wide. Bárðarbunga erupted in late August 2014, the eruption style effusive , which is common in Iceland, but had not been seen for a few years. Lava covered the surrounding landscape northwest of the Vatnajökull glacier. Bárðarbunga is a subglacial stratovolcano and central volcano under the ice cap of Vatnajökull glacier in

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816-485: Is associated with a second central volcano Hamarinn which has been classified historically as part of a separate Loki-Fögrufjöll volcanic system. Hamarinn is 20 km (12 mi) to the south-west of the Bárðarbunga central volcano. While the central volcanoes of the Bárðarbunga volcanic system are under the western edge of the Vatnajökull ice cap, the system's northern fissure swarm and lava flows extend around

884-665: Is believed to have been related to the triggering of the eruption in Gjálp. On the other hand, because the magma erupted showed strong connections to the Grímsvötn Volcanic System according to petrology studies, the 1996 as well as a former eruption at Gjálp in the 1930s are thought to have taken place within Grímsvötn Volcanic system. A week-long eruption occurred at Grímsvötn starting on 28 December 1998, but no glacial burst occurred. In November 2004,

952-399: Is evidence of many smaller eruptions during the past 10,000 years. Þjórsá Lava , the largest Holocene lava flow on earth, originated from Bárðarbunga about 8,600 years ago, with a total volume of 21 to 30 cubic kilometres and covering approximately 950 square kilometres. Many large eruptions have occurred south-west of the glacier; the first occurring since human settlement of Iceland was

1020-547: Is first eruption timed to the day. The Laki eruptions which were both effusive and explosive between June 1783 and February 1784, produced the Skaftáreldahraun lava flows, which cover a large part of south-east Iceland. Before this the tip of the Rauðhólar-Eldgígur fissure system was active with the production of the 4550 BCE Botnahraun lava flow which extends beyond the furtherest extent to the south of

1088-420: Is not proven. Bárðarbunga is named after an early Icelandic settler named Gnúpa-Bárður [ˈknuːpa-ˌpaurðʏr̥] , and literally translates as "Bárður's bulge" or "Bárður's bump" since "Bárðar" is the genitive case of "Bárður". Throughout history, there have been large eruptions every 250–600 years. In 1477, the largest known eruption from Bárðarbunga had a volcanic explosivity index (VEI) of 6; there

1156-476: Is often felsic , having high to intermediate levels of silica (as in rhyolite , dacite , or andesite ), with lesser amounts of less viscous mafic magma . Extensive felsic lava flows are uncommon, but can travel as far as 8 km (5 mi). The term composite volcano is used because the strata are usually mixed and uneven instead of neat layers. They are among the most common types of volcanoes; more than 700 stratovolcanoes have erupted lava during

1224-604: Is part of the Eastern volcanic zone of Iceland , and is directly over the Iceland mantle plume . The volcanic system has crater rows extending to the south east; the 25 km (16 mi) long Laki–Grímsvötn fissure system and the 30 km (19 mi) long Rauðhólar-Eldgígur fissure system. The Rauðhólar-Eldgígur fissure system has been related by some authors to an alignment with the Thordarhyrna central volcano with

1292-451: Is the most famous example of a hazardous stratovolcano eruption. It completely smothered the nearby ancient cities of Pompeii and Herculaneum with thick deposits of pyroclastic surges and pumice ranging from 6–7 meters deep. Pompeii had 10,000-20,000 inhabitants at the time of eruption. Mount Vesuvius is recognized as one of the most dangerous of the world's volcanoes, due to its capacity for powerful explosive eruptions coupled with

1360-450: Is typically between 700 and 1,200 °C (1,300-2,200 °F). Volcanic bombs are masses of unconsolidated rock and lava that are ejected during an eruption. Volcanic bombs are classified as larger than 64mm (2.5 inches). Anything below 64mm is classified as a volcanic block . When erupted Bombs are still molten and partially cool and solidify on their descent. They can form ribbon or oval shapes that can also flatten on impact with

1428-403: Is very dangerous because its magma has an unusually low silica content , making it much less viscous than other stratovolcanoes. Low viscosity lava can generate massive lava fountains , while lava of thicker viscosity can solidify within the vent, creating a volcanic plug . Volcanic plugs can trap gas and create pressure in the magma chamber, resulting in violent eruptions. Lava

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1496-463: The 2010 eruption of Eyjafjallajökull . The ash cloud from the eruption rose to 20 km (12 mi), and was so far 10 times larger than the 2004 eruption, and the strongest in Grímsvötn in the last 100 years. Disruption to air travel in Iceland commenced on 22 May, followed by Greenland, Scotland, Norway, Svalbard and a small part of Denmark on subsequent days. On 24 May

1564-824: The Holocene Epoch (the last 11,700 years), and many older, now extinct, stratovolcanoes erupted lava as far back as Archean times. Stratovolcanoes are typically found in subduction zones but they also occur in other geological settings. Two examples of stratovolcanoes famous for catastrophic eruptions are Krakatoa in Indonesia (which erupted in 1883 claiming 36,000 lives) and Mount Vesuvius in Italy (which erupted in 79 A.D killing an estimated 2,000 people). In modern times, Mount St. Helens (1980) in Washington State , US, and Mount Pinatubo (1991) in

1632-579: The Philippines have erupted catastrophically, but with fewer deaths. Stratovolcanoes are common at subduction zones , forming chains and clusters along plate tectonic boundaries where an oceanic crust plate is drawn under a continental crust plate (continental arc volcanism, e.g. Cascade Range , Andes , Campania ) or another oceanic crust plate ( island arc volcanism, e.g. Japan , Philippines , Aleutian Islands ). Stratovolcanoes also occur in some other geological settings, for example as

1700-486: The Vatnajökull National Park in Iceland. It is one of the six volcanic systems under Vatnajökull. The central volcano has a rim that rises to about 2,000 m (6,600 ft) above sea level, making it the second highest mountain in Iceland , being lower than Hvannadalshnjúkur . The caldera is about 65 km (25 sq mi), up to 10 km (6.2 mi) wide and about 700 m (2,300 ft) deep. The surrounding edges rise to 1,850 m (6,070 ft), but

1768-512: The Vatnaöldur eruption about 877 ± 2 CE which had a volcanic explosivity index (VEI) of 4. The Veiðivötn eruption in 1477 is the largest known Icelandic eruption, with a VEI of 6. Studies of tephra layers have shown that a number of eruptions have occurred beneath the glacier, probably in the northeast of the crater or in Bárðarbunga. There have also been smaller eruptions in an ice-free area of Dyngjuháls [ˈtiɲcʏˌhauls] to

1836-891: The magma is too viscous to allow easy escape of volcanic gases . As a consequence, the tremendous internal pressures of the trapped volcanic gases remain and intermingle in the pasty magma . Following the breaching of the vent and the opening of the crater, the magma degasses explosively. The magma and gases blast out with high speed and full force. Since 1600 CE , nearly 300,000 people have been killed by volcanic eruptions . Most deaths were caused by pyroclastic flows and lahars , deadly hazards that often accompany explosive eruptions of subduction-zone stratovolcanoes. Pyroclastic flows are swift, avalanche-like, ground-sweeping, incandescent mixtures of hot volcanic debris, fine ash , fragmented lava , and superheated gases that can travel at speeds over 150 km/h (90 mph). Around 30,000 people were killed by pyroclastic flows during

1904-443: The mantle which decreases its melting point by 60 to 100 °C. The release of water from hydrated minerals is termed " dewatering ", and occurs at specific pressures and temperatures for each mineral, as the plate descends to greater depths. This allows the mantle to partially melt and generate magma . This is called flux melting . The magma then rises through the crust , incorporating silica-rich crustal rock, leading to

1972-554: The moment magnitude scale . In August 2014, a swarm of around 1,600 earthquakes in 48-hours, with magnitudes up to 4.5 M W , was followed on 23 August by the USGS Aviation Color Codes being raised from orange to red, indicating an eruption in progress. The following day, the aviation risk was lowered from red to orange and the statement that there was an eruption in progress was retracted. However, later aerial observations of glacial depressions southeast of

2040-616: The 1902 eruption of Mount Pelée on the island of Martinique in the Caribbean . During March and April 1982, El Chichón in the State of Chiapas in southeastern Mexico , erupted 3 times, causing the worst volcanic disaster in that country's history and killied more than 2,000 people in pyroclastic flows . Two Decade Volcanoes that erupted in 1991 provide examples of stratovolcano hazards. On 15 June, Mount Pinatubo erupted and caused an ash cloud to shoot 40 km (25 mi) into

2108-485: The 1982 eruption of Galunggung in Java , British Airways Flight 9 flew into the ash cloud, causing it to sustain temporary engine failure and structural damage. Although no crashes have happened due to ash, more than 60, mostly commercial aircraft , have been damaged. Some of these incidents resulted in emergency landings. Ashfalls are a threat to health when inhaled and are also a threat to property. A square yard of

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2176-585: The 5,321 m (17,457 ft) high Andean volcano. The ensuing lahar killed 25,000 people and flooded the city of Armero and nearby settlements. As a volcano forms, several different gases mix with magma in the volcanic chamber. During an eruption the gases are then released into the atmosphere which can lead to toxic human exposure. The most abundant of these gases is H 2 O ( water ) followed by CO 2 ( carbon dioxide ), SO 2 ( sulfur dioxide ), H 2 S ( hydrogen sulfide ), and HF ( hydrogen fluoride ). If at concentrations of more than 3% in

2244-471: The Grímsvötn-Laki volcanic system. The compositional separation from nearby systems has been studied in some detail, and is used to assign lava and tephra deposits to the volcanic system. Some of the tephra's erupted have transpired to have mixed compositions with nearby volcanic systems and it is not known if this is due to dual eruptions or intusions crossing magma reserviors. The volcanic system

2312-456: The Holuhraun area, along the same volcanic fissure, which started shortly after 4 am on 31 August. The eruption emitted large volumes of sulphur dioxide and impacted air quality in Iceland. There was no effect on flights outside of the immediate vicinity as the eruption hadn't produced a significant amount of volcanic ash . On 28 February 2015, it was officially reported that the eruption

2380-501: The Icelandic Meteorological Office increased the alert level for Grímsvötn from yellow to orange, after a series of earthquakes was detected. On 7 December, the alert level was lowered back to yellow, after seismic activity decreased and no signs of eruptive activity were detected. On 11 December 2023, a jökulhlaup followed in time, a M w 4.5 earthquake. Tephra studies on soil samples from around

2448-512: The Laki lava field. The Rauðhólar-Eldgígur fissure system also formed the Núpahraun lava flows around 4000 BP that extend from the Vatnajökull glacier towards the south east coast and are covered in part by the northern Laki Skaftáreldahraun lava flow. There are two recent pre-historic but undated Bergvatnsárhraun lava flows just on the south-eastern edge of the Vatnajökull glacier, related to

2516-499: The Laki–Grímsvötn more in alignment with the Grímsvötn central volcano. Eruptives from Grímsvötn and Thordarhyrna are able to be geochemically distinguished between, so it is possible that the two central volcanoes are not one system. Thordarhyrna has rhyolite formations which have not been found at Grímsvötn. Studies indicate that volcanic activity in Iceland rises and falls so that the frequency and size of eruptions in and around

2584-491: The Richter scale, is believed to have started the eruption in Gjálp. On the other hand, because the magma erupted showed strong connections to the Grímsvötn Volcanic System as petrology studies showed, the 1996, as well as a former eruption in the 1930s, are thought to have taken place within Grímsvötn Volcanic system. On 26 September 2010, an earthquake swarm was recorded with over 30 earthquakes measuring up to 3.7 M W on

2652-426: The Vatnajökull ice cap varies with time. It is believed that the four eruptions between 1996 and 2011 could mark the beginning of an active period, during which an eruption in Grímsvötn in Vatnajökull may be expected every 2–7 years. Parallel volcanic activity in nearby Bárðarbunga is known to be associated with increased activity in Grímsvötn. Seismic activity has been increasing in the area in recent years, indicating

2720-461: The Vatnajökull ice cap was reported. The water contains elevated levels of dissolved hydrogen sulfide, suggesting increased volcanic activity under the ice. Jökulhlaup (glacial lake flooding) can occur before or after an eruption. On 4 December 2021, a jökulhlaup occurred from Grímsvötn into the Gígjukvísl river, with an average flow of 2,600 m /s (92,000 cu ft/s). Two days later,

2788-416: The Vatnajökull ice-cap, show that the Grímsvötn volcanic system has high activity for Iceland, and had between 4 to 14 explosive eruptions every 100 years (mean about 7 eruptions every 100 years) between 7600 years ago and 870 AD. For technical reasons only the last 10,200 years of explosive eruptions have been characterised locally, and the record gets more inaccurate with time especially prior to 1598, which

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2856-819: The air, when breathed in CO 2 can cause dizziness and difficulty breathing. At more than 15% concentration CO 2 causes death. CO 2 can settle into depressions in the land, leading to deadly, odorless pockets of gas. SO 2 classified as a respiratory, skin, and eye irritant if come into contact with. It is known for its pungent egg smell and role in ozone depletion and has the potential to cause acid rain downwind of an eruption. H 2 S has an even stronger odor than SO 2 as well as being even more toxic. Exposure for less than an hour at concentrations of over 500 ppm causes death. HF and similar species can coat ash particles and once deposited can poison soil and water. Gases are also emitted during volcanic degassing, which

2924-748: The air. It produced large pyroclastic surges and lahar floods that caused a lot of damage to the surrounding area. Pinatubo , located in Central Luzon just 90 km (56 mi) west-northwest of Manila , had been dormant for six centuries before the 1991 eruption. This eruption was one of the 2nd largest in the 20th century. It produced a large volcanic ash cloud that affected global temperatures, lowering them in areas as much as .5 °C. The volcanic ash cloud consisted of 22 million tons of SO 2 which combined with water droplets to create sulfuric acid . In 1991 Japan's Unzen Volcano also erupted, after 200 years of inactivity. It's located on

2992-831: The base is on average close to 1,100 m (3,600 ft). The volcano is covered in ice to a depth of 850 m (2,790 ft), hiding the glacier -filled crater. The associated volcanic system and fissure swarm is about 190 km (120 mi) long and 25 km (16 mi) wide. Bárðarbunga was a little-known volcano in Iceland due to its remote location and infrequent eruptions approximately once every 50 years, but recent studies have shown that many tephra layers originally thought to be from other volcanoes were ejected from Bárðarbunga, and that lateral dyke intrusions may trigger eruptions in adjacent volcanoes. Sustained seismic activity had been gradually increasing in Bárðarbunga and its associated northern fissure system for seven years starting in 2007 and leading to an eruption towards

3060-530: The crater. In June 2020, the Icelandic Meteorological Office (IMO) issued a warning that an eruption might take place in the coming weeks or months, following scientists reporting high levels of sulfur dioxide , which is indicative of the presence of shallow magma. IMO warned that a glacial flood as a result of melting ice could trigger an eruption. No eruption occurred. In September 2021, an increase in water outflow from under

3128-507: The crew managed to reach the emergency transmitter in the plane's rubber liferaft and send out a distress call which was picked up by the Icelandic Coast Guard vessel Ægir . The same day a search and rescue Catalina aircraft, named Vestfirðingur , spotted them. The C-54's cargo included the body of a deceased United States Air Force (USAF) colonel, prompting American assistance. A USAF C-47 equipped with skis landed on

3196-468: The disruption spread to Northern Ireland and to airports in northern England. The cancellation of 900 out of 90,000 European flights in the period 23–25 May was much less widespread than the 2010 disruption after the Eyjafjallajökull eruption. The eruption stopped at 02:40 UTC on 25 May 2011, although there was some explosive activity from the eruptive vents affecting only the area around

3264-498: The end of 2014. This activity had decreased after the Grímsvötn eruption in 2011 , but later returned to a similar level as before the eruption. The previous Bárðarbunga eruption was in 1910. There has been frequent volcanic activity outside the glacier to the south-west in the highlands between Vatnajökull and Mýrdalsjökull , and also to the north-east toward Dyngjufjöll [ˈtɪɲcʏˌfjœtl̥] . The Bárðarbunga volcanic system

3332-409: The findings could help identify how to look for life on Mars. There is the potential for mechanical interaction such as dyke propagation between Grímsvötn and Thordarhyrna. Interactions can also occur with the nearby Bárðarbunga volcano, which is part of a separate volcanic system. The volcano erupts predominantly tholeiitic basalt , and a close chemical affinity exists with the other lavas of

3400-540: The flank of a volcano collapses in a massive landslide) can only trigger the eruption of a very shallow magma chamber . Magma differentiation and thermal expansion also are ineffective as triggers for eruptions from deep magma chambers . In recorded history , explosive eruptions at subduction zone ( convergent-boundary ) volcanoes have posed the greatest hazard to civilizations. Subduction-zone stratovolcanoes, such as Mount St. Helens , Mount Etna and Mount Pinatubo , typically erupt with explosive force because

3468-455: The glacier but was unable to take off again, so it had to be abandoned. After six days both crews were rescued by a ski-patrol from Akureyri . Later Loftleiðir bought the stranded C-47 from the USAF for $ 700. In April 1951 it was dug out of the snow and towed down the mountain by two bulldozers, where it was started and flown to Reykjavík. Stratovolcano A stratovolcano , also known as

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3536-478: The ground. Volcanic Bombs are associated with Strombolian and Vulcanian eruptions and basaltic lava . Ejection velocities ranging from 200 to 400 m/s have been recorded causing volcanic bombs to be destructive. Lahars (from a Javanese term for volcanic mudflows) are a mixture of volcanic debris and water. Lahars can result from heavy rainfall during or before the eruption or interaction with ice and snow. Meltwater mixes with volcanic debris causing

3604-458: The high population density of the surrounding Metropolitan Naples area (totaling about 3.6 million inhabitants). In addition to potentially affecting the climate, volcanic ash clouds from explosive eruptions pose a serious hazard to aviation . Volcanic ash clouds consist of ash which is made of silt or sand sized pieces of rock, mineral, volcanic glass . Ash grains are jagged, abrasive, and don't dissolve in water. For example, during

3672-460: The highest eruption frequency of all the volcanoes in Iceland. It has a southwest-northeast-trending fissure system. The massive climate-impacting Laki fissure eruption of 1783–1784 took place in a part of the same Grímsvötn-Laki volcanic system. Grímsvötn was erupting at the same time as Laki during 1783, but continued to erupt until 1785. Because most of the volcanic system lies underneath Vatnajökull, most of its eruptions have been subglacial and

3740-481: The ice cap, allowing huge quantities of water to escape rapidly. Earthquakes and seismic tremor may occur. Jökulhlaup can occur independent of eruptions or be followed by eruptions. Jökulhlaup independent of eruptions occurred in November, December 2021 and October 2022. Jökulhlaup which were followed by eruptions occurred in 1922, 1934 and 2004. Consequently, the Grímsvötn caldera is monitored very carefully. When

3808-430: The interaction of magma and meltwater from the ice causes phreatomagmatic explosive activity. Within the Grímsvötn-Laki volcanic system is a second central volcano called Thordarhyrna (Þórðarhyrna). Eruptions in the caldera regularly cause glacial outbursts known as jökulhlaup . Eruptions or geothermal activity, melt enough ice to fill the Grímsvötn caldera with water, and the pressure may be enough to suddenly lift

3876-504: The island of Kyushu about 40 km (25 mi) east of Nagasaki . Beginning in June, a newly formed lava dome repeatedly collapsed. This generated a pyroclastic flow that flowed down the mountain's slopes at speeds as high as 200 km/h (120 mph). The 1991 eruption of Mount Unzen was one of the worst volcanic disasters in Japan's history, once killing more than 15,000 people in 1792. The eruption of Mount Vesuvius in 79 AD

3944-468: The line of the Rauðhólar-Eldgígur fissures. In 2004, a community of bacteria was detected in water of the Grímsvötn lake under the glacier, the first time that bacteria have been found in a subglacial lake. The lakes never freeze because of the volcanic heat. The bacteria can also survive at low concentrations of oxygen . The site is a possible analogue for life on the planet Mars , because there are also traces of volcanism and glaciers on Mars and thus

4012-518: The north-east. Eruptions appear to follow a cycle: there were several eruptions in the glacier between 1701 and 1740 and since 1780. 1910 was the last known significant eruption of the Bárðarbunga volcanic system before the 2014 eruptions. It occurred in the Loki-Fögrufjöll volcano. The Gjálp fissure vent eruption in 1996 revealed that an interaction may exist between Bárðarbunga and Grímsvötn . A strong earthquake in Bárðarbunga, about 5 on

4080-464: The size of Mount Pinatubo affected the weather for a few years; with warmer winters and cooler summers observed. A similar phenomenon occurred in the April 1815, the eruption of Mount Tambora on Sumbawa island in Indonesia . The Mount Tambora eruption is recognized as the most powerful eruption in recorded history. Its eruption cloud lowered global temperatures as much as 0.4 to 0.7 °C. In

4148-503: The southern flanks of the Askja volcano and the southern fissure swarm extends past the north-west of Torfajökull and almost reaches Tindfjallajökull . The southern lava flows have reached the sea near Selfoss . It is now known that within the area of the rhyolitic caldera of Torfajökull there are younger extrusives that involve basaltic magma mixing events by lateral propagation, from the fissure swarm of Bárðarbunga's volcanic system. To

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4216-464: The volcano suggested that the now-retracted report of an eruption had been correct and that a short eruption did occur under the ice, but the lack of further melting indicated that this eruption had now ceased. Then, a new fissure eruption breached the surface between Bárðarbunga and Askja , in the Holuhraun lava field, in the early hours of 29 August. This was followed by a second fissure eruption in

4284-419: The volcano, indicating magma movement under the caldera. On 1 November 2010 meltwater from the Vatnajökull glacier was flowing into a lake, suggesting that an eruption of the underlying volcano could be imminent. On 21 May 2011 at 19:25 UTC , an eruption began, with 12 km (7 mi) high plumes accompanied by multiple earthquakes , Until 25 May, the eruption scale had been larger than that of

4352-477: The west of the central volcanoes is the less active volcanic system of Tungnafellsjökull and to the central volcanoes south west, also under Vatnajökull is the very active Grímsvötn volcanic system. In the 1996 eruption of Gjálp which is usually assigned to the Grímsvötn volcanic system, studies are consistent with the eruption being triggered by a 10 km (6.2 mi) lateral dyke intrusion at about 5 km (3.1 mi) depth from Bárðarbunga, although this

4420-412: The world. The SO 2 in this cloud combined with water (both of volcanic and atmospheric origin) and formed sulfuric acid , blocking a portion of the sunlight from reaching the troposphere . This caused the global temperature to decrease by about 0.4 °C (0.72 °F) from 1992 to 1993. These aerosols caused the ozone layer to reach the lowest concentrations recorded at that time. An eruption

4488-479: The year following the eruption, most of the Northern Hemisphere experienced cooler temperatures during the summer. In the northern hemisphere , 1816 was known as the " Year Without a Summer ". The eruption caused crop failures, food shortages, and floods that killed over 100,000 people across Europe , Asia , and North America . Gr%C3%ADmsv%C3%B6tn Grímsvötn is a basaltic volcano which has

4556-416: Was over. Nevertheless, the gas pollution still existed, and the area north of Bárðarbunga, including volcanoes Askja and Herðubreið , still remained closed for visitors. On 16 March 2015, the area north of Bárðarbunga was opened for visitors, excluding the new lava field and the area within 20 metres around it. On 21 April 2024 a M w 5.3 earthquake occurred in the Bárðarbunga volcanic system. This

4624-608: Was the largest earthquake under this region of the Vatnajökull icecap since the 2015 eruption and was associated with isolated smaller fore- and aftershocks but no other markers of potential volcanic activity. On 14 September 1950 a Douglas C-54 Skymaster aircraft belonging to the Icelandic airline Loftleiðir crash landed on the Vatnajökull glacier at Bárðarbunga during a cargo flight from Luxembourg to Reykjavík . There were no fatalities, but damaged radio equipment left them unable to communicate their location. After two days

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