Icelandic Volcano Update

Holuhraun Eruption in Iceland Still Going Strong

Part of the Holuhraun eruption in Iceland, seen on October 21, 2014. Photo by Milan Nykodym / Flickr.

If you can believe it, we’re now in the fourth month for the Icelandic eruption that started north of the Bárðarbunga caldera in Iceland. The world watched and waited for this eruption after weeks of intense earthquakes, but since the eruption began in late August, we’ve had a nearly constant stream of basaltic magma eruption from the fissures in the Holuhraun lava fields between Bárðarbunga and Askja. This eruption has drifted from the headlines because the eruptive activity itself has been fairly tame — no giant ash plumes to disrupt air travel across Europe, but instead just a steady flow of lava creating a new lava field that covers over 72 square kilometers (~17,700 acres; see below). You can watch some great slow-motion footage of the lava erupting at one of the main vents, taken October 27 by Karl Neusinger – it really shows the constant influx of lava from below that creates the impressive lava flow field. This eruption at Holuhraun now has the distinction of being the largest (by volume) in Iceland since the massive 1783-4 eruption of Laki (although Holuhraun trails Laki by “only” 16 cubic kilometers of lava!)

The Holuhraun lava field (shown in white outline) and the active vent seen by Landsat 8 on November 16, 2014. Image by University of Iceland Institute of Earth Sciences / IMO.

The biggest hazard produced by the eruption so far has been to the air quality in Iceland, where the sulfur dioxide emissions from such a constant and vigorous basaltic eruption has meant that people have been required to stay indoors during much of the summer and fall months on the island nation. Analyses of the rainwater in Iceland over the past months show that as much as 40% of the rain that has fallen is acidic (pH <7) with some rain as low as pH 3.5 (as John Stevenson put it, that’s like grapefruit juice rain).

At Bárðarbunga, the floor of the caldera has continued to subside during this whole eruption without much signs that any eruptions have occurred under the ice that fills the caldera (however, the increased heat from the geothermal system may have melted some of that ice). That, in itself, is interesting and tells us something about how some of these Icelandic calderas can form. Instead of the catastrophic events that many people envision for caldera formation (e.g., Crater Lake), these are slow subsidence events that might takes months to occur. Calderas at other large shield volcanoes have also formed in this fashion, but to be able to measure the motion so precisely is a great scientific bonanza. Large earthquakes are still occurring under the caldera as well, with a M5.4 happening just yesterday (November 18).

The NASA Earth Observatory recently posted an image of the plume from the Holuhraun fissure that shows how the plume itself might interact with the clouds around the eruption. More likely than not, eruption plumes can play a role in cloud formation and distribution around a volcano.



Hawaii, Iceland Volcanic activity

Eruption Update: New Fissure Eruption Starts Closer to Vatnajökull in Iceland, Kilauea Lava Flow Threatens Homes

Lava fountaining in the second fissures in the Holuhraun lava field, Iceland, seen on September 4, 2014. Photo by Image from  Jonni Productions video.

Two updates for today, dominated by action at the two most famous hotspots on the planet:


A new fissure started erupting this morning to the south of the current activity in the Holuhraun lava fields in Iceland. These two new fissures are closer to the Vatnajökull ice cap (just 2 km north of its edge), so concern is growing larger than the eruption will start happening subglacially, potentially causing jökulhlaups (glacial outburst floods) as the lava erupts under the ice. The Icelandic Meteorological Office is also reporting that the cauldron (depression) in Dyngjujökull, the northern part of the ice cap, is getting larger and more pronounced, both of which are signs that more heat is being felt at the bottom of the ice (possibly caused by eruptions under the ~300-350 meters of ice). Check out these images of the cauldron on the ice surface. The most serious ramification is the potential for more explosive style of eruption if water can mix with the lava.

So far, the vigor of the eruption at the new fissures is lower than the other active fissures, where lava fountains (see above) are reaching over 100 meters into the air. Be sure to check out these great images of the lava fountaining, spatter cones and lava flows of the larger fissure field. The older lava flow field now covers just over 10 square kilometers. Watch this video to see what it’s like to get up close and personal with the lava flows right now.


The steam plume from the eruption is reaching 4.5 km (15,000 feet) and the sulfur dioxide plume is beginning to spread beyond the region right around Iceland. Changes in the weather patterns around the island suggest that the plume may spread enough to reach Europe, although the only possible ramifications of that might be some sulfur odor across the British Isles.


Lava flows approaching KKK Homesteads on Kilauea's slopes, seen on September 3, 2014. Photo by Hawaii Volcano Observatory / USGS.

Meanwhile, in Hawai’i, lava flows are threatening homes on the slopes of Kilauea (see above). The USGS has raised the alert status at Kilauea to its highest – Warning – after lava flows exploiting a ground crack moved downslope and re-emerged near the Kaohe Homesteads. This lava flow was able to move so much further downslope thanks to the insulating nature of the ground crack, keeping the lava hot enough to flow longer and faster. At the current rates of flow, the lava could reach the Homesteads in 5-7 days if it continues to exploit the ground cracks. Currently, the lava flows are burning their way through the forested lands on the flank of Kilauea. The Hawaii Volcano Observatory has an excellent collection of images of the lava flows, showing how it is advancing towards the homesteads. Although these lava flows aren’t a hazard for people as such, previous lava flows have destroyed entire communities on the slopes of the volcano.


Bardarbunga Volcano, Iceland Activity

Earthquakes Still Rocking Iceland’s Barðarbunga

The volcanic wastelands between Barðarbunga and Askja in Iceland, seen in 2012. Photo by Dave McGarvie, used by permission.

It has now been over 4 days of intense seismicity at Iceland Barðarbunga, located under the Vatnajökull ice cap. The latest report from the Icelandic Meteorological Office (IMO) says that over 2,600 earthquakes, most less than M3, have occurred since the morning of August 16. The activity has shifted in its focus (see below) and is now primarily under a part of Vatnajökull that is ~600 meter thick, so any eruption would have a lot of ice to melt when the lava reaches the surface. This likely means that it would be a long time before any eruption would be noticed on the surface of the ice cap – instead, it would be glacial outburst floods (jökulhlaups) that would herald the start of the eruption. If the eruption never breaches the surface of the ice cap, there is the potential of a new tuya forming under the ice, where lava forms a broad, flat-topped mountain. Beyond the seismicity, we’ve also seen deformation around the focus of the earthquakes, suggesting magma is filling in below and needs to make space by moving the Earth’s surface. IMO says most of the seismicity is occurring at depths between 3-7 km but there aren’t signs yet that the magma is moving to shallower depths, so we still could see this all end as merely the intrusion of magma rather than an eruption. The alert status for Barðarbunga remains at Orange.


The location of earthquakes near Barðarbunga, color-coded to time (blue is earlier in the day, red is later - see hours marked on scale to right). Illustration by Iceland Meteorological Office.

If you want to see what some of the potential scenarios, be sure to read Dr. Dave McGarvie’s article. Also, there are now two webcams pointed at the Barðarbunga area, so you can keep an eye on it if any potential eruption manifests at the surface: Mila and You can also see some realtime earthquake data in 3D (note: I can’t guarantee the accuracy of this model and more recent earthquakes do not have accurate depths until they have been examined) on this interactive page.