Eruptions of Eyjafjallajökull

2010 eruptions of Eyjafjallajökull are a timeline of volcanic events at Eyjafjöll 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. 14-20 April ash covered large areas of northern Europe when volcano erupted. About 20 countries closed their airspace and it affected hundreds of thousands of travellers. The European flights avoided about 344,109 tonnes of CO2 emissions per day, while the volcano emitted about 150 000 tonnes of CO2 per day.

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 Europe's 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 of the eruption started on 14 April 2010 and resulted in an estimated 250 million cubic metres (330,000,000 cu yd) (¼ km3) of ejected tephra. The ash plume rose to a height of approximately 9 kilometres (30,000 ft), 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 morning of 24 May 2010, the view from the web camera installed on Þórólfsfell showed only a plume of water vapour surrounded by a blueish haze caused by the emission of sulphurous gases.

Due to the large quantities of dry volcanic ash lying on the ground, surface winds frequently lifted up an "ash mist" that significantly reduced visibility and made web camera observation of the volcano impossible.

By the evening of 6 June 2010, a small, new crater had opened up on the west side of the main crater from which explosive activity was observed with the 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 is officially over, although the area is still geothermally active and might erupt again.

Scientific observations

This eruption has been assigned the volcano number 1702-02 by the Global Volcanism Program.

The London Volcanic Ash Advisory Centre (VAAC), part of the UK Met Office, is responsible for forecasting the presence of volcanic ash in the north-east Atlantic. All ash dispersion models for this geographic region are produced by the VAAC in London.

A study by the Icelandic Meteorological Office published on December 2009 indicated an increase in seismic activity around the Eyjafjallajökull area during the years 2006–2009. The study reported increased activity that occurred between June and August 2009 (200 events), compared to a total of about 250 earthquakes recorded between September 2006 and August 2009. It further indicated that the locations of most of the earthquakes in 2009 occurred between 8 to 12 kilometres (5.0 to 7.5 mi) depth east of the volcano‘s top crater. At the end of December 2009, seismic activity began around the Eyjafjallajökull volcano area, with thousands of small earthquakes (mostly of magnitude 1–2 Mw), 7 to 10 kilometres (4.3 to 6.2 mi) beneath the volcano.

The radar stations of the Meteorological Institute of Iceland did not detect any appreciable amount of volcanic ashfall during the first 24 hours of the eruption. However, during the night of 22 March, they reported some volcanic ash fall reaching the Fljótshlíð area (20 to 25 kilometres (12 to 16 mi) north-west of the eruption's location)and Hvolsvöllur town (40 kilometres (25 mi) north-west of the eruption location) leaving vehicles with a fine grey layer of volcanic ash. At around 07:00 on 22 March, an explosion launched eruption columns as far as 4 kilometres (13,000 ft) straight up into the air. This was the highest plume since the eruption started. On 23 March, a small vapour explosion took place, when hot magma came into contact with nearby snowdrifts, emitting a huge vapour plume which reached an altitude of 7 kilometres (23,000 ft), and was detected on radars from the Meteorological Institute of Iceland. Since then many vapour explosions have taken place.

By 26 February 2010 the Global Positioning System (GPS) equipment used by the Iceland Meteorological Office at Þorvaldseyri farm in the Eyjafjöll area (around 15 kilometres (9.3 mi) southeast of the location of the recent eruption) had shown 3 centimetres of displacement of the local crust in a southward direction, of which a 1 centimetre displacement had taken place within four days. (See the GPS Time Series page of the Nordic Volcanological Center's website for detailed information on the degree of movement detected in the Earth's crust in the Eyjafjallajökull locality.)

Effect on river water

On 22 March, a flow meter device situated in the Krossá glacial river (which drains Eyjafjallajökull and Mýrdalsjökull glaciers) in the Þórsmörk area (a few kilometres north-west of the erupting location) started to record a sudden rise in water level and in water temperature – the total water temperature rose by 6 °C (11 °F) over a two-hour period, which had never occurred so quickly in the Krossá river since measurements began. Shortly afterward, the water level returned to normal and water temperature decreased as well.[ It is thought that this rise in water temperature is related to the eruption nearby and is affecting part of the Krossá drainage basin. The temperature of Hruná river, which flows through the narrow Hrunárgil canyon, into which part of the lava stream has been flowing, was recently recorded by geologists to be between 50 °C (122 °F) and 60 °C (140 °F), indicating that the river has been cooling the lava in that canyon.

Comparison to other recent eruptions

The recent eruptions of Eyjafjallajökull and the largest ash plume associated with the second eruption phase were not unparalleled in either volume or abundance; however, the location was the critical factor because it affected air travel across Europe. Neither phase of the eruption was unusually powerful. Other notable volcanic eruptions in recent years include the eruption of Mount Pinatubo of 1991 of VEI 6. This eruption lasted 8 days, from 7 – 15 June of that year, with an ash cloud that would have required additional days to dissipate, and resulted in worldwide abnormal weather and decrease in global temperature over the next few years. However, the second phase of Eyjafjallajökull's eruption lasted longer than that of Mount Pinatubo.

According to the SI / USGS Weekly Volcanic Activity Report (14–20 April 2010) by the Smithsonian's Global Volcanism Program, the second eruption phase at Eyjafjallajökull coincided with eruptions at a number of other volcanoes, including new activity at original research?

Barren Island, Andaman, India plume rose to an altitude of 2.4 kilometres (7,900 ft) and drifting 55 kilometres (34 mi) to the north on 19 April 2010.

Gaua, Banks Islands, SW Pacific, Vanuatu ash plumes reported from during 13–16 and 19–21 April 2010. The plumes regularly rose to altitudes of 3 kilometres (9,800 ft). A spokesman for the Vanuatu Disaster Management Office described the activity as "huge, dark plumes" in an AAP news report.