The Eyjafjallajökull and Katla relationship
Eyjafjallajökull is an interesting volcano, not least because of its relationship with its near neighbour, Katla. This much larger volcano lies less than 30 km to the east of Eyjafjallajökull, beneath the Myrdalsjökull icecap. Katla is, the Global Volcanism Program reports, ‘one of Iceland’s most active [volcanoes] and is a frequent producer of damaging jökulhlaups, or glacier-outburst floods’. Katla, with more than twenty confirmed eruptions since the sixth century AD, has a much more active eruptive history than Eyjafjallajökull, which has just three eruptions over the same period. It seems, however, that there is a connection between these two closely-spaced volcanoes. Eyjafjallajökull’s most recent eruption, December 1821 to January 1823, was followed by an eruption of Katla in June and July 1823. More recently an intrusion at Eyjafjallajökull in 1999 appears to have been followed by a small subglacial eruption in the Katla caldera. It’s intriguing that recent earthquake activity around Katla and Eyjafjallajökull has clustered in three areas: (1) shallow quakes around and within the Eyjafjallajökull caldera, (2) shallow quakes largely confined to the eastern part of Katla caldera, and (3) quakes with a deeper focus in the Godabunga area between the first two clusters. One possible interpretation of this pattern is that a cryptodome – an underground lava dome – is active beneath this area. The presence of viscous rhyolitic lava beneath Katla and Eyjafjallajökull makes for potentially explosive eruptive activity, if an eruption occurs. An Icelandic commenter at Eruptions reports that the Iceland Meteorologial Office do not expect an eruption at Eyjafjallajökull. The volcano may get over its current bout of restlessness and calm down again, as happened with the intrusion events of 1994, 1999 and 2009. It clearly needs careful watching, however, as does its large and destructive neighbour, Katla.
For all the worldwide chaos that Iceland's volcano has already created, it may just be the opening act. Scientists fear tremors at the Eyjafjallajokull (ay-yah-FYAH-lah-yer-kuhl) volcano could trigger an even more dangerous eruption at the nearby Katla volcano - creating a worst-case scenario for the airline industry and travelers around the globe. How big would a Katla eruption be?
A Katla eruption would be 10 times stronger and shoot higher and larger plumes of ash into the air than its smaller neighbor, which has already brought European air travel to a standstill for five days and promises severe travel delays for days more. The two volcanos are side by side in southern Iceland, about 12 miles (20 kilometers) apart and thought to be connected by a network of magma channels. Katla, however, is buried under ice 550 yards (500 meters) thick - the massive Myrdalsjokull glacier, one of Iceland's largest. That means it has more than twice the amount of ice that the current eruption has burned through - threatening a new and possibly longer aviation standstill across Europe. Katla showed no signs of activity Tuesday, according to scientists who monitor it with seismic sensors, but they were still wary. [ BREITBART ]
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