Code red as Icelandic volcano erupts
So far, the eruption appeared to consist mainly of basaltic lava, which does not create the explosive ash clouds that are hazardous to aviation and in some cases can affect the Earth's climate.
However, the Icelandic Meteorological Office issued a code red aviation alert, which indicates that an eruption is occurring or is imminent, and potentially hazardous to aircraft. No ash clouds had been detected by the UK Met office, which monitors such hazards throughout Europe, as of midnight eastern time.
The volcano caused a lot of problems for exporters in 2010 and forced more than 100,000 flights to and from Europe to be canceled.
On its website, the meteorological office stated: "An eruption started in Holuhraun north of Dyngjujökull at around 00:02. Seismic tremor was observed on all seismic stations and the web camera installed in the area by Mila has showed some nice pictures of the eruption. It is a small fissure eruption and at 02:40 a.m. the activity appears to have decreased."
The eruption is a type known as a "fissure eruption," which occurs when lava escapes through cracks or vents in the ground. Fissure eruptions don't typically explode with large clouds of ash, but this one is occurring at the north end of an underground flow of molten rock, or magma, that has been traveling in a dike from the Bardabunga volcano, underneath the Vatnajokull glacier (known in Iceland as the Dyngjujökull glacier) and about 30 miles toward the nearby Askja volcano.
The fissure appears to have opened beyond the glacier, but on recent survey flights above the volcano, scientists have observed some melted ice and cracks, indicating that magma may have come into contact with the ice at some point.
Should this continue or intensify, it could trigger flooding, and the mixture of lava and thick ice tends to enhance the explosiveness of some volcanic eruptions, such as Iceland's Laki volcano, which erupted in 1783. That eruption threw so many sulfate aerosol particles, which were contained in the ash cloud, into the atmosphere that it cooled the planet for a few years afterwards.
The interaction between the two volcanoes and their underground magma chambers and channels are complex and leave open the possibility of a large, explosive eruption.
"The dike has now reached the fissure system of the Askja volcano and GPS measurements indicate that the area there is greatly affected," the Iceland Meteorological Office said on its website.
According to the agency, since midnight on August 28, more than 1,100 earthquakes were detected in association with the volcanic activity, including a 5.0 magnitude quake near the northern rim of the sunken Bardarbunga crater, known as a caldera. A 5.7 magnitude earthquake shook the volcano on Tuesday, which was the strongest since the heightened activity began on August 16.
To further complicate matters, remnants of Hurricane Cristobal are expected to strike Iceland over the weekend, bringing strong winds and heavy rain.