Icelandic Volcano Erupts – UPDATE

Eruption at Eyjafjöll is consistent with recent global patterns of volcanism and tectonism. Wild eruptions may occur in Iceland and elsewhere—Fire-Earth

Eyjafjöll Volcanic System Erupts

Eyjafjallajökull volcanic system erupted in the south of Iceland, forcing up to five hundred people to evacuate the area, prompting the authorities to declare a state of emergency and imposing a NO FLY Zone  over much of Icelandic airspace.

Background: Volcano erupts near Eyjafjallajoekull, Iceland

At least three flights en-route Reykjavik from the US were ordered back to Boston, and up to 1,500 are currently stranded in the Reykjavik airport.

Where the Eruption Occurred

Location of the Eruptive Fissure. Source: Nordic Volcanological Center. Click image to enlarge.

How Eruption Occurred

Eruption began at 23:52UTC on 20 March 2010 at  the Eyjafjallajökull volcanic system (also known as Eyjafjöll volcano). A red cloud appeared above the volcano, which lightened up the sky above the eruptive fissure. “The eruption was preceded with intense seismicity and high rates of deformation in the weeks before the eruption, in association with magma recharging of the volcano. Immediately prior to the eruption the depth of seismicity had become shallow, but was not significantly enhanced from what it had been in the previous weeks. Deformation was occurring at rates of up to a centimetre a day since March 4 at continuous GPS sites installed within 12 km from the eruptive site.” IESUI reported.

“The eruption broke out with fire fountains and Hawaiian eruptive style on about 500 m long NE-SW oriented eruptive fissure at N63º38.1′, W19º26.4′ on the northeast shoulder of the volcano at an elevation of about 1000 m. It was observed from air from 4-7 A.M. on March 21. Lava flows short distance from the eruptive site, and minor eruption plume at elevation less than 1 km was deflected by wind to the west. Volcanic explosive index (VEI) is 1 or less. Tephra fall is minor or insignificant. The eruption occurs just outside the ice cap of Eyjafjallajökull, and no ice melting is occurring at present.”

Surface temperature satellite image taken by MODIS shows the location of the eruption. Source: NASA via Nordic Volcanological Center. Click image to enlarge.

Source: Nordic Volcanological Center. Click image to enlarge.

The eruption occurred at a fissure on a 2 km wide pass of ice-free land between Eyjafjallajökull and its large neighbor Katla volcano which is buried under Myrdalsjökull ice cap. “Katla volcano is known for powerful subglacial phreatomagmatic eruptions producing basaltic tephra layers with volumes ranging from ~0.01 to more than 1 cubic kilometer.” Institute of Earth Sciences at University of Iceland (IESUI) reported.

Eyjafjallajökull is known to have erupted at least three times in the last 1100 years (settlement of Iceland). “The most recent began in December 1821 and lasted intermittently for more than a year. The neighbouring volcano Katla erupted then on 26 June 1823. Other eruptions include an eruption in 1612 or 1613, and about 920 A.D.”

Eyjafjallajökull is known for several episodes of unrest, “with documented sill intrusions in 1994 and 1999.”

The 2.5-km-wide summit caldera of Eyjafjöll located west of Katla volcano. Photo by Oddur Sigurdsson, 1992 (Icelandic National Energy Authority). Click image to enlarge.

Seismic Activity

Eyjafjallajökull has been experiencing intensive Seismic activity since late February with most of the shocks occurring at 7 to 10 km depth. “On March 19th a seismic swarm began east of the top crater, originating between 4 and 7 km depth.” Iceland Met Office reported.

“On March 19th a seismic swarm, began east of the top crater, originating between 4 and 7 km depth. The activity migrated eastwards and towards the surface on Saturday, March 20th.”

What Local Experts Say

Scientists at Nordic Volcanological Center say further volcanic activity in the area may be imminent, based on the fact that three previous eruptions at Eyjafjallajokull had all primed the powerful Katla volcano to erupt.

“What we know is that an eruption in Eyjafjallajokull seems to be a trigger for Mt Katla,” geophysicist Pall Einarsson said.

“The volcano has been inflating since the beginning of the year, both rising and swelling, even though we were seeing increased seismic activity, it could have been months or years before we saw an eruption like this.”

Einarsson believes that an eruption at Mt Katla would be a much greater and more serious event because molten lava would melt the glacier causing large-scale flooding.

Geophysicist Magnus Gudmundsson says it’s impossible to predict how long the Eyjafjallajokull eruption could last. “It could end tomorrow, it could go on for a year or two, but this is a small eruption.”

More facts about Icelandic Volcanoes:

• Mt Katla last erupted in 1918.
• The most recent eruption at an Icelandic volcano occurred in 2004.
• Eyjafjallajokull Volcanic System was dormant since 1821.
• Iceland has experienced 21 eruptions in the past 50 years.
• Only one of the 21 eruption caused serious damage  when a volcano erupted in Westmann islands in 1973.

Map of Iceland Earthquakes (Last 48 hours) – Icelandic Met Office

© Veðurstofa Íslands

Related Links:

• Volcanoes
• FEWW Volcano Links
• Eruption Caught on Video by Iceland Coast Guard (WMV)