Exception or Rule? The Case of Katla, One of Iceland’s Subglacial Volcanoes

Katla Volcano in Iceland on GlacierHub
Grasslands in the foreground, with Katla covered by clouds in the background (Source: Inga Vitola/Flickr).

A recent study in Geophysical Research Letters about Katla, a subglacial volcano in Iceland, revealed that Katla emits CO2 at a globally important level. Previously, Katla’s CO2 emissions were assumed to be negligible on a global scale.

In this study, conducted by Evgenia Ilyinskaya, a volcanologist at the University of Leeds, and her associate researchers, airborne measurements were carried out using gas sensors to obtain CO2 source and emission rates for Katla. In addition, the researchers used atmospheric dispersion modeling to identify the source of gas emissions and calculate gas emission rates.

A CO2 emission rate of 12-24 kilotons per day is considered significant on a global level. Ilyinskaya and coauthors’ measurements taken on the western side of Katla indicated significant CO2 flux levels in both 2016 and 2017. Also in 2017, the researchers identified another significant source of CO2 emissions, Katla’s central caldera.

Katla 1918 eruption on GlacierHub
Katla’s last eruption was in 1918 (Source: Creative Commons).

Emissions estimates that are both accurate and representative for subglacial volcanoes are challenging to obtain. According to the study, this is because these volcanoes are hard to access and “lack a visible gas plume.” The researchers noted that CO2 flux measurements are available for just two of Iceland’s 16 subglacial volcanoes, and these measurements indicate only modest emissions estimates. Further, these measurements were obtained by analyzing gas content dissolved in water, a method which likely underestimates CO2 flux. Ilyinskaya and her coauthors used a more precise estimate in this study than previous methods, such as the one discussed above.

Total CO2 emissions from passively degassing subaerial volcanoes are currently estimated at 1,500 kt/d, and CO2 flux is currently estimated at 540 kt/d. The results Ilyinskaya and the other researchers found indicate that Katla’s CO2 emissions would account for 2-4 percent of that total. However, they stipulated that subglacial volcanoes were underrepresented in the data collected to create this estimate. Measurements from 33 volcanoes were extrapolated to cover CO2 emissions of 150 volcanoes, but only three of the 33 were subglacial volcanoes.

Myrdalsjokull glacier covering Katla volcano on GlacierHub
View of the Myrdalsjokull glacier, which covers Katla (Source: Zaldun Urdina/Flickr).

Regarding Katla, Ilyinskaya and coauthors identified two possible implications of this information. First, Katla could be an exceptional emitter. Katla’s large size and recent heightened seismic activity make this possibility more plausible. But the researchers pointed out that measurements must be conducted at other subglacial volcanoes before this possibility can be corroborated.

A second possibility is that Katla’s CO2 emissions are representative of what other subglacial volcanoes emit. If this is true, estimates of CO2 emissions from subglacial volcanoes are grossly underestimated at present. Once measured properly, these volcanoes would make a much more significant contribution to global volcanic CO2 emissions. Currently, subaerial volcano CO2 emissions are assumed to be just 2 percent of anthropogenic CO2 emissions totals, but this could change with improved measurement practices.

Myrdalsjokull glacier above Katla volcano on GlacierHub
Atop the Myrdalsjokull glacier, with Katla beneath it (Source: Adam Russell/Flickr).

In the context of climate change, it is important that CO2 emissions from natural sources are adequately quantified alongside anthropogenic sources. As the results of this study suggest, subglacial volcanoes such as Katla could have emissions contributions that are more significant than originally thought. Ilyinskaya and her fellow researchers stressed the vital importance of conducting similar measurements at other subglacial volcanoes to ensure that their CO2 emissions are properly quantified in global estimates.

Ash from Iceland’s Glacier Volcano Threatens Health of Local Children

The prolonged eruption of the glacier volcano Eyjafjallajökull in Iceland in 2010 released 250 million tons of ash (Source: Bjarki Sigursveinsson/Flickr).

The prolonged eruption of the glacier volcano Eyjafjallajökull in Iceland in 2010 released 250 million tons of ash, exposing residents to dangerous levels of the substance. The spread of the volcanic dust and ash caused by this event has since raised concerns about the long-term health risks to vulnerable populations. A recent study by Heidrun Hlodversdottir and her co-authors of the physical and mental health of the local children following the eruption of the Eyjafjallajökull volcano suggests that they were more likely to experience respiratory and anxiety issues than those who were not impacted by the eruption, among other negative effects.

The research, published in the European Journal of Psychotraumatology, assessed the health impacts of the eruption for a period of three years after the climate event. The authors analyzed both the exposed and non-exposed adult population through questionnaires aimed at examining their children’s and their own perceived health status in 2010, six to nine months after the eruption, as well as three years later.

Hlodversdottir and her co-authors explained in a joint response to GlacierHub that the winds carried the ash across Europe and North Africa, increasing concerns that the eruption could possibly affect the respiratory health of the local population. Precautions for susceptible individuals were issued in Europe by the World Health Organization and national health authorities following the eruption. According to the WHO, health surveillance systems in countries in the WHO European Region detected no exposure of the populations to volcano-related air pollution and no health effects potentially related to volcanic ash following the volcanic eruption, the authors said. However, the south and southeast of Iceland received a great deal of ash and residue during six weeks and several months following the eruption. Thus, the researchers compared data from exposed and non-exposed regions in Iceland. In 2010, they gathered demographic data from each child’s parents and asked questions about property losses. In 2013, those who participated in the study were contacted again for a second evaluation about perceived health status.

In 2010, the study revealed that children who had been exposed to the impacts of the volcano were more prone to respiratory problems, anxiety and worries, headaches, and poor sleep. Gisli Palsson, professor of anthropology at the University of Iceland, told GlacierHub that the latter three might also be related to concerns caused by radical changes in the children’s lives generated by the impact of the volcanic eruption.

In 2010, the study revealed that children exposed to volcanic ash were more prone to respiratory problems, anxiety, headaches and poor sleep (Source: Chris Ford/Flickr).

The authors of the study further indicated to GlacierHub that a threatening, uncontrollable and unpredictable natural event so close to people´s homes is a major stressor. “The ash from the Eyjafjallajökull eruption damaged property, reduced visibility, delayed transportation, and many inhabitants had to evacuate their homes for a period of time. The continuous ashfall darkened the environment to the point of turning daylight into night, as well as glacier flooding, heavy lightning strikes, loud volcanic sound blasts and lava flows; all impacting the daily life of the exposed residents,” the authors note.

Although the eruption did not result in casualties, these events were stressful enough and caused uncertainty during and after the eruption. These stressors, in addition to the physical effects of ash exposure, may have contributed to the negative impacts on the children’s well-being, they added.

In addition, while the study did not compare gender regarding the continuity of symptoms, the results when analyzed by gender demonstrated that exposed male children had a higher likelihood of experiencing sleep disturbances and headaches than non-exposed male children.

Hlodversdottir and her co-authors indicated that it is important to note that all the measures of children’s health were based on the parents’ reporting. “It is well documented that internalized difficulties such as anxiety symptoms are more prevalent among girls and that boys show more often externalized difficulties,” they said. “It is therefore possible that boys in our study did not express their emotions verbally as much as girls but rather expressed their emotions as physical symptoms, i.e. headaches and sleeping difficulties. It is also possible that the children´s parents interpreted their children´s symptoms and behavior differently instead of the volcano eruption having different effects on gender.”

The results from the evaluation made in 2013 suggested that certain health problems— for example, depression and sleeping disturbances— were still present years after the event. The prevalence of these issues was linked to the gravity of the hazard that children had experienced.

Moreover, the researchers investigated the predictive factors that could cause these symptoms. In this aspect, they found that children who had experienced material damages were at higher risk of mental issues such as anxiety and depression when compared to those who were not exposed to these situations.

The authors indicated to GlacierHub that disasters can generate mental damage to families. For this reason, disaster interventions should focus on assisting people impacted by climate events. There is limited research on the impacts and long-term health effects of volcanic eruptions on children’s health, as well as knowledge on disaster risk populations among youth.

The authors added that there are indications in the literature that the academic environment is a convenient area to inform youth regarding preparedness and possible risks. Furthermore, parents should be advised on how to discuss these issues with their children.

Over 500 million people are located near active volcanoes, and children are the most vulnerable to the impacts of volcanic hazards. For this reason, it is important that governments develop strategies to prevent and reduce possible health issues on vulnerable populations. In addition, there must be more of an effort to continuously assess the health of the most vulnerable populations following a natural hazard. As Hlodversdottir and her co-authors told GlacierHub, “Children are a particularly vulnerable group that needs developmentally appropriate treatments that are evidence-based and affordable. It is therefore of great importance that such service be funded and made available in the long term after natural disasters.”

Iceland’s Öræfajökull Volcano, Buried Under Glacier, Shows Signs of Activity

The Öræfajökull volcano in Iceland is showing signs of activity this month, bringing interest and intrigue to the long dormant volcano whose last known eruption was in 1727-1728. Like many other volcanoes in Iceland, Öræfajökull, the country’s tallest volcano, is mostly buried underneath glacier. The recent activity has caused a large depression in the ice, forming what is referred to as an ice cauldron or subsidence bowl.

The presence of ice could cause an eruption to be phreatomagmatic, which refers to a reaction of magma with ice that causes steam to be released. According to Benjamin Edwards, a volcanologist at Dickinson College in Carlisle, Pennsylvania, “Even a small eruption will likely produce significant melting given the amount of ice in the summit caldera, and in an environment where water can’t leave the area around the volcanic vent rapidly it will probably cause phreatomagmatic eruptions, which are highly explosive.”

It is difficult to know what caused the ice cauldron to form because of limitations in instrumentation, though subglacial eruptions can still be detected through seismic signatures also known as eruption tremors. According to Dave McGarvie, professor at Open University in Milton Keynes, England, the cauldron could be formed due to a small amount of magma that was released or simply from rising heat. He added, “What can be said with certainty is that the presence of a heat source beneath the ice-filled caldera of this volcano is highly unusual. No subsidence bowl in the ice of this caldera has been recorded in the past few centuries.” Cauldrons are found throughout Iceland and have the potential to cause floods. “There are numerous examples of subsidence bowls in Icelandic glaciers that appear to be caused purely by heating– such as those at the ice-covered Katla volcano, and the famous Skaftá cauldrons, which drain periodically and create sizeable glacial outburst floods.”



For this reason, scientists believe Öraefajökull has started to wake up. “Whether she’s just rolling over in her sleep, or getting ready to fully waken up– nobody knows. It’s too early to tell,” McGarvie added.

Past eruptions from Öræfajökull have been devastating and helped give the volcano the first part of its Icelandic name, roughly translating to wasteland, wilderness, or desolation, which describes the post-eruption surrounding region (the second half, “jökull” means glacier). M Jackson, a geographer and glaciologist who has done research on Iceland said, “The idea of Öræfajökull erupting is terrifying, especially when you put it the historical context. When Iceland was settled over 1,000 years ago, the area around Öræfajökull was verdant and forested, but in 1362 the volcano underneath the glacier Öræfajökull erupted, triggering catastrophic jökulhlaups [type of glacier lake outburst flood] that flooded and decimated the entire region.”

Iceland has plans in place if Öræfajökull erupts including partially closing the ring road which encircles the country and links all the major settlements. Gísli Pálsson, a professor of anthropology at the University of Iceland, explained that if an eruption does occur, an immediate alert will be sent to nearby communities with requests for evacuation of farming communities and possibly the town of Höfn and the village of Kirkjubæjarklaustur. ”The worst scenario would be heavy floods and massive clouds and layers of ash,” he said.

The Icelandic government and community is well-prepared in case an eruption does occur. “Volcanic activity in Iceland is ongoing, and embedded in the social fabric of Icelandic society,” said Jackson. “Volcanic activity is reported in the news regularly, and people are vigilant. The government monitors all activity intensely, and the system is highly functional. When I lived in Iceland, I was impressed how often I received alerts for any activity, such as earthquakes, gas leaks, and floods.”

The interaction between melting glaciers and erupting volcanoes can be causal as well. Pálsson said it seems likely that with the thinning of the glacier, a circular pattern is established and eruptions will be more frequent than before, resulting in further thinning of the glacier. “An interesting and possibly devastating spinoff from global warming,” he said.

According to Jackson, Iceland’s largest icecap, Vatnajökull, is located above a hotspot, with many volcanoes buried underneath glaciers. In the last eight hundred years, Vatnajökull has experienced over eighty subglacial volcanic eruptions alone, she said. Many scientists speculate that as Vatnajökull increasingly melts, the rate of volcanic eruptions and earthquakes will increase. “The material products of increased volcanic activity are likely to have long lasting effects on Icelandic society,” she said.

In 2010, Iceland’s Eyjafjallajökull volcano eruption released ash clouds that disrupted air travel in and throughout Europe for an entire week. Öræfajökull could erupt a similar ash cloud, as could other volcanoes in Iceland. With climate change potentially increasing the frequency of eruptions, the world has one more important reason to quickly mitigate the effects of climate change.

Photo Friday: A Visit to Volcano Museums in Iceland

Like millions of other travelers, Gísli Pálsson found that his travel plans were stymied by the 2010 eruption of Iceland’s glacier-covered Mt. Eyjafjallajökull, which canceled transatlantic flights and generated a glacial meltwater flood. As a professor of anthropology at the University of Iceland, Pálsson responded to the inconvenience in a creative way– by starting a project called Volcanologues, in which he and others affected by the eruption share their stories.

As part of Volcanologues, Pálsson recently visited two museums that opened after the eruption: the Lava Center at Hvolsvöllur, and the other on a farm named Þorvaldseyri, as part of the “Eyjafjallajökull Erupts” tour. Check out his pictures, read this piece he wrote for GlacierHub, and start dreaming up your own visit to learn more about this historic eruption.

Watch footage of the glacial flood caused by Mt. Eyjafjallajökull’s eruption:


A visitor experiences the magnitude of the Eyjafjallajökull eruption (Source: Gísli Pálsson/Facebook).
This mural depicts, in its words, the “island mountain glacier volcanic eruption” (Source: Gísli Pálsson/Facebook).


Visitors learn about glacial outburst floods (Source: Gísli Pálsson/Facebook).


The farm Þorvaldseyri is near Mt. Eyjafjallajökull (Source: Gísli Pálsson/Facebook).


A museum representation of the lava flow (Source: Gísli Pálsson/Facebook).

Will An Icelandic Volcano Erupt Under A Glacier In 2015?

Lava at Bardarbunga and volcanic gasses (Photo: Ragnar Axelsson/ Morgnebladid)
Lava at Bardarbunga and volcanic gasses (Photo: Ragnar Axelsson/ Morgnebladid)

A group of well-placed observers have warned the world about the possibility of a major volcanic eruption in Iceland in 2015. Steen Jakobsen, the chief economist of the Danish trading and investment firm Saxo Bank, and the bank’s strategy team have issued their “Outrageous Predictions” for the coming year.

They state that these predictions are “independent calls on events that can upset global markets or politics. They are strategic in nature rather than an exercise in getting everything right, while our aim is to encourage alternative thinking.” An eruption of the Barðarbunga volcano could send a cloud of ash and noxious gasses that would threaten to block incoming solar radiation and cause crop failures across Europe, leading to rising food prices and political unrest.

A Land Rover crossing the lava field. (Photo: Arni Saeberg/Morgenbladid)
A Land Rover crossing the lava field. (Photo: Arni Saeberg/Morgenbladid)

Even if the ultimate consequences of the eruption were not so severe, the fear of poor harvests could drive food prices skyward and create severe economic and political disruptions. Saxo Bank mentioned other possible threats in 2015, including a housing market crash in the UK, Japanese inflation reaching 5 percent, a spike in cacao prices that would make chocolate much more expensive, and the resignation of Mario Draghi, the current head of the European Central Bank.

It might seem that these predictions are merely an effort of Saxo Bank to use improbable disaster scenarios to garner public attention during the news lull over the holiday season. But their track record is better than such a view would suggest. One of their predictions for 2014, “Brent crude drops to USD 80/barrel as producers fail to respond” came true, when oil prices fell below that benchmark on November 13 of that year. In 2011, three of Saxo Bank’s ten predictions proved to be correct: the yield on the U.S. 30-year Treasury bills fell below 3 percent, crude oil prices rose above $100 and then fell, and the price of gold surged past $1,800 an ounce. They did well with gold in 2013 as well, when the price of the metal, which had been rising steadily for more than a decade, tumbled and in December passed below $1,200 an ounce, as they predicted.

Moreover, volcanoes can indeed emit enough ash to block solar radiation and cause crop failures. The 1783-84 eruption of Laki in Iceland led to low yields in France and other parts of Europe and was, as Saxo Bank suggested, a contributing factor to the French Revolution in 1789. The 1815 eruption of Tambora in Indonesia caused food shortages in Europe and North America, and probably in Asia as well.

Volcanic gasses over Icelandic highlands. (Photo: Ragnar Axelsson/Morgenbladid)
Volcanic gasses over Icelandic highlands. (Photo: Ragnar Axelsson/Morgenbladid)

However, the Barðarbunga volcano and the associated Holuhraun lava field have been behaving in a fairly calm manner. Indeed, the Icelandic volcanologist Páll Einars­son has termed it a “peaceful eruption,” adding that, “it just keeps go­ing day af­ter day with lit­tle changes.” There are many signs of this orderly behavior. The movement of magma through subterranean passages shakes the earth in a steady rhythm, with several quakes reaching 5 on the Richter scale every month and many more less powerful ones. The volcanic caldera continues to subside, as magma flows away to new areas, where it can emerge. The fissures keeps on issuing significant amounts of lava. Holuhraun is reaching an area of 80 square kilometers, about the size of the island of Manhattan, and the volume of lava is more than a cubic kilometer. Fortunately, the lava has been moving to the north and east, away from the major glaciers, particularly Vatnajökull.

Current sulfur dioxide observations in Iceland (red=present, green=absent) (Source: Icelandic Environmental Agency)
Current sulfur dioxide observations in Iceland (Red = present, Green = absent) (Source: Icelandic Environmental Agency)

Scientists recognize that the future is uncertain. The eruption could taper off, or lava could emerge under glacial ice, it would create explosive bursts of steam, which would send large volume of ash high in the atmosphere and massive floods of meltwater as well. However, major problem for Iceland to date has been the massive releases of sulfur dioxide, a noxious gas that affects different parts of the country as winds shift, sometimes creating health problems, particularly for the elderly and people with respiratory conditions. For the time being, the warning level for an ash cloud is orange rather than the more serious level red. And the Institute of Earth Sciences told its followers on Facebook “We’ll keep an eye on the lava, but… Merry Christmas!” Let us hope that Saxo Bank’s prediction does not come to pass.

Extent of Bardarbunga lava field in mid-December. (Source: Icelandic Meteorological Office)
Extent of Bardarbunga lava field in mid-December. (Source: Icelandic Meteorological Office)
A Christmas greeting from the Department of Earth Sciences, University of Iceland. (Source: DES, University of Iceland/Facebook)
A Christmas greeting from the Department of Earth Sciences, University of Iceland. (Source: DES, University of Iceland/Facebook)

GlacierHub has been covering Barðarbunga extensively since the first signs of possible volcanic activity, during the first eruption, and subsequently.