Harmful particles in Icelandic volcanic ash fell first, says new research

The type of particles which are most harmful to jet engines were the first to fall out of the Eyjafjallajökull ash plume following the volcano’s eruption in 2010, delegates at the Goldschmidt conference will be told today (Wednesday 28th August).

The research, led by Dr Bernard Grobety of the University of Fribourg in Switzerland, will help to mitigate the impact of future volcanic eruptions on air travel.

Dr Grobety’s team analysed samples of volcanic ash taken at different points in its journey from the volcano across Europe. They found that the two different forms of the ash particles – crystalline and glassy – behaved differently during transport. As the plume travelled through the air, the crystalline particles, which are denser and heavier, fell out of the cloud first compared to even-sized glassy particles.

“It’s already known that the larger, heavier particles in an ash cloud will be the first to fall out as the cloud travels away from a volcano,” explains Dr Grobety. “It is also clear that particles of equal size but higher density will fall out faster. Our research, however, is the first to evidence the faster loss of crystalline particles in a volcanic cloud and that the overall composition of the ash changes during transport. Since crystalline particles are harder and melt at higher temperatures, they are more harmful to jet engines than glassy particles. Understanding the behaviour of these different forms in the ash cloud will enable the authorities to fine tune their response should another volcanic eruption take place.

The 2010 eruption of Eyjafjallajökull caused air traffic in Europe to be grounded for six days, with widespread disruption in over 20 countries. There has been extensive research since 2010 to reduce the impact of future eruptions, but much of the research treats the ash cloud as homogenous, focusing on its concentration and the size of particles within it. Dr Grobety’s research adds another layer of detail which could reduce the impact of any eruption still further.

“We’re already at the point where we can say that if the ash is at a certain concentration and a certain particle size, it poses no threat to aircraft,” says Dr Grobety. “However, it’s possible that even at a higher concentration, if no crystalline particles are present, planes may still be safe to fly. By monitoring how quickly these particles are falling out of the cloud, it could reduce the area affected or help restrictions to be lifted sooner.

“However, there are a lot of factors which will determine the impact of any future eruptions – from the nature of the eruption itself, to the prevailing winds and the concentration of the ash. While the detail we’re able to provide may be only one of many factors to take into account, anything that can limit the disruption to air travel has to be worth looking at.

‘Highway from hell’ fueled Costa Rican volcano

Volcanologist Philipp Ruprecht analyzed crystals formed as Irazú's magma cooled to establish how fast it traveled. -  Kim Martineau
Volcanologist Philipp Ruprecht analyzed crystals formed as Irazú’s magma cooled to establish how fast it traveled. – Kim Martineau

If some volcanoes operate on geologic timescales, Costa Rica’s Irazú had something of a short fuse. In a new study in the journal Nature, scientists suggest that the 1960s eruption of Costa Rica’s largest stratovolcano was triggered by magma rising from the mantle over a few short months, rather than thousands of years or more, as many scientists have thought. The study is the latest to suggest that deep, hot magma can set off an eruption fairly quickly, potentially providing an extra tool for detecting an oncoming volcanic disaster.

“If we had had seismic instruments in the area at the time we could have seen these deep magmas coming,” said the study’s lead author, Philipp Ruprecht, a volcanologist at Columbia University’s Lamont-Doherty Earth Observatory. “We could have had an early warning of months, instead of days or weeks.”

Towering more than 10,000 feet and covering almost 200 square miles, Irazú erupts about every 20 years or less, with varying degrees of damage. When it awakened in 1963, it erupted for two years, killing at least 20 people and burying hundreds of homes in mud and ash. Its last eruption, in 1994, did little damage.


Irazú sits on the Pacific Ring of Fire, where oceanic crust is slowly sinking beneath the continents, producing some of earth’s most spectacular fireworks. Conventional wisdom holds that the mantle magma feeding those eruptions rises and lingers for long periods of time in a mixing chamber several miles below the volcano. But ash from Irazú’s prolonged explosion is the latest to suggest that some magma may travel directly from the upper mantle, covering more than 20 miles in a few months.

“There has to be a conduit from the mantle to the magma chamber,” said study co-author Terry Plank, a geochemist at Lamont-Doherty. “We like to call it the highway from hell.”

Their evidence comes from crystals of the mineral olivine separated from the ashes of Irazú’s 1963-1965 eruption, collected on a 2010 expedition to the volcano. As magma rising from the mantle cools, it forms crystals that preserve the conditions in which they formed. Unexpectedly, Irazú’s crystals revealed spikes of nickel, a trace element found in the mantle. The spikes told the researchers that some of Irazú’s erupted magma was so fresh the nickel had not had a chance to diffuse.


“The study provides one more piece of evidence that it’s possible to get magma from the mantle to the surface in very short order,” said John Pallister, who heads the U.S. Geological Survey (USGS) Volcano Disaster Assistance Program in Vancouver, Wash. “It tells us there’s a potentially shorter time span we need to worry about.”

Deep, fast-rising magma has been linked to other big events. In 1991, Mount Pinatubo in the Philippines spewed so much gas and ash into the atmosphere that it cooled Earth’s climate. In the weeks before the eruption, seismographs recorded hundreds of deep earthquakes that USGS geologist Randall White later attributed to magma rising from the mantle-crust boundary. In 2010, a chain of eruptions at Iceland’s Eyjafjallajökull volcano that caused widespread flight cancellations also indicated that some magma was coming from down deep. Small earthquakes set off by the eruptions suggested that the magma in Eyjafjallajökull’s last two explosions originated 12 miles and 15 miles below the surface, according to a 2012 study by University of Cambridge researcher Jon Tarasewicz in Geophysical Research Letters.

Volcanoes give off many warning signs before a blow-up. Their cones bulge with magma. They vent carbon dioxide and sulfur into the air, and throw off enough heat that satellites can detect their changing temperature. Below ground, tremors and other rumblings can be detected by seismographs. When Indonesia’s Mount Merapi roared to life in late October 2010, officials led a mass evacuation later credited with saving as many as 20,000 lives.

Still, the forecasting of volcanic eruptions is not an exact science. Even if more seismographs could be placed along the flanks of volcanoes to detect deep earthquakes, it is unclear if scientists would be able to translate the rumblings into a projected eruption date. Most problematically, many apparent warning signs do not lead to an eruption, putting officials in a bind over whether to evacuate nearby residents.

“[Several months] leaves a lot of room for error,” said Erik Klemetti, a volcanologist at Denison University who writes the “Eruptions” blog for Wired magazine. “In volcanic hazards you have very few shots to get people to leave.”

Scientists may be able to narrow the window by continuing to look for patterns between eruptions and the earthquakes that precede them. The Nature study also provides a real-world constraint for modeling how fast magma travels to the surface.

“If this interpretation is correct, you start having a speed limit that your models of magma transport have to catch,” said Tom Sisson, a USGS volcanologist based at Menlo Park, Calif.

Olivine minerals with nickel spikes similar to Irazú’s have been found in the ashes of arc volcanoes in Mexico, Siberia and the Cascades of the U.S. Pacific Northwest, said Lamont geochemist Susanne Straub, whose ideas inspired the study. “It’s clearly not a local phenomenon,” she said. The researchers are currently analyzing crystals from past volcanic eruptions in Alaska’s Aleutian Islands, Chile and Tonga, but are unsure how many will bear Irazú’s fast-rising magma signature. “Some may be capable of producing highways from hell and some may not,” said Ruprecht.

Months of geologic unrest signaled reawakening of Icelandic volcano

Months of volcanic restlessness preceded the eruptions this spring of Icelandic volcano Eyjafjallajökull, providing insight into what roused it from centuries of slumber.

An international team of researchers analyzed geophysical changes in the long-dormant volcano leading up to its eruptions in March and April 2010 that suggest that magma flowing beneath the volcano may have triggered its reawakening. Their study is published in the Nov. 18 issue of the journal Nature.

“Several months of unrest preceded the eruptions, with magma moving around downstairs in the plumbing and making noise in the form of earthquakes,” says study co-author Kurt Feigl, a professor of geosciences at the University of Wisconsin-Madison. “By monitoring volcanoes, we can understand the processes that drive them to erupt.”

With funding from a RAPID grant from the U.S. National Science Foundation, Feigl and collaborators from Iceland, Sweden, and the Netherlands used a combination of satellite imaging and GPS surveying to watch the volcano’s edifice as it deformed. They found that the volcano swelled for 11 weeks before it began to erupt in March 2010 from one flank.

“If you watch a volcano for decades, you can tell when it’s getting restless,” Feigl says.

In late summer 2009, a subtle shift at a GPS station on Eyjafjallajökull’s flank prompted the study’s lead author, Freysteinn Sigmundsson, and his colleagues to begin monitoring the mountain more closely. Then, in early January 2010, the rate of deformation and the number of earthquakes began to increase. As the deformation and seismic unrest continued, the researchers installed more GPS stations near the mountain. Just a few weeks later, the instruments detected more rapid inflation, indicating that magma was moving upwards through the “plumbing” inside the volcano.

By the time the volcano began to erupt on March 20, the volcano’s flanks had expanded by more than six inches as magma flowed from deep within the Earth into shallow chambers underneath the mountain.

Surprisingly, the rapid deformation stopped as soon as the eruption began. In many cases, volcanoes deflate as magma flows out of shallow chambers during an eruption. Eyjafjallajökull, however, maintained basically the same inflated shape through mid-April, when the first eruption ended.

After a two-day pause, the volcano began to erupt again on April 22. This time, the lava broke out through a new conduit under the ice on the summit of the mountain, causing an explosive reaction as water flashed to steam and gas escaped from bubbles in the magma. The resulting “ash” plume rose high into the atmosphere, disrupting air traffic over Europe for weeks and stranding millions of travelers.

Why did Eyjafjallajökull erupt when it did? The geologic processes that trigger an actual eruption are not yet well understood, says Feigl. “We’re still trying to figure out what wakes up a volcano.”

To begin to answer this question, the scientists suggest that a magmatic intrusion deep within the volcano may have triggered the eruption, but this hypothesis remains to be tested at other volcanoes.

They are also studying the structures inside the volcano, such as magma chambers and intrusive conduits, by extracting information from the sensors installed around Eyjafjallajökull.

“The explosiveness of the eruption depends on the type of magma, and the type of magma depends on the depth of its source,” Feigl says. “We’re a long way from being able to predict eruptions, but if we can visualize the magma as it moves upward inside the volcano, then we’ll improve our understanding of the processes driving volcanic activity.”

Scientists collaborate to study Eyjafjallajokull lightning

For travelers in Europe, the recent eruption of Iceland’s Eyjafjallajokull [AY-uh-fyat-luh-YOE-kuutl-uh] meant a major disruption in business and travel plans. For Alaska volcano researchers, the eruption has offered a chance to learn more about the way volcanoes work.

In the wake of the eruption, the University of Alaska Fairbanks Geophysical Institute and the New Mexico Institute of Mining and Technology have teamed up again to study the lightning produced during volcanic eruptions. Past collaborations have found researchers studying the eruptions of Augustine, Pavlof and Redoubt volcanoes in Alaska, as well as Chaiten Volcano in Chile.

To study Eyjafjallajokull, researchers from New Mexico Tech have set up six instruments near the volcano as part of a lightning-mapping array. The sensor stations consist of an omnidirectional antenna hooked up to an electronics package, a data recorder, a GPS clock and other components.

The Eyjafjallajokull research is still in its infancy, but project member Steve McNutt, Alaska Volcano Observatory coordinating scientist at the Geophysical Institute, notes the research team has already observed some unusual and understudied phenomena, such as lightning that is propagated upward from the volcano’s vent toward the sky and into the ash plume. Iceland’s glacial terrain has also created some unique volcanic activity.

“Something relatively new with Iceland is that (the eruption) occurred under glacial ice,” McNutt said. “Ice is interesting because it’s the most electro-positive substance known.”

Water droplets have a negative charge, so eruption through the glacial ice creates some dynamic electrical conditions in the atmosphere.

Lightning is just one element of volcanic activity that scientists are trying to better understand. More pressing for stranded travelers, for instance, is that the scientific and aviation communities are still uncertain about the dangers posed by ash clouds, so caution tends to rule the day.

“We don’t really know what a safe level of ash in the atmosphere is,” McNutt said. “Your only safe choice is to completely avoid it.”

The collaboration between UAF and New Mexico Tech on Eyjafjallajokull offers the chance to continue gathering data for the foreseeable future. The collaboration is in the final year of a three-year National Science Foundation grant.

Iceland volcano: Researcher compiles first high-res images; plume receding but internal heat up

Day time plume compositional image derived from the thermal infrared data - Credit: University of Pittsburgh
Day time plume compositional image derived from the thermal infrared data – Credit: University of Pittsburgh

High-resolution visible and thermal infrared images captured by a joint NASA-Japanese satellite sensor and compiled by University of Pittsburgh volcanologist Michael Ramsey provide the first clear glimpse of the Icelandic volcano Eyjafjallajökull that has disrupted air travel worldwide since it began erupting April 14.

Ramsey, an associate professor in Pitt’s Department of Geology and Planetary Science, collected images taken by NASA’s Earth-orbiting Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) instrument showing that although the volcano’s infamous ash plume is receding, its internal temperature is rising.

The images are available on Pitt’s Web site at http://www.pitt.edu/~mramsey/data/iceland. Eyjafjallajökull appears on the left side of the images as a bright spot with a cloud emanating from it.

Ramsey, who is available to comment on the images and Eyjafjallajökull’s activity, is a member of the ASTER science team and specializes in remote sensors and visualization as applied to volcanoes. His work with ASTER usually centers on the north Pacific region, but the satellite was redirected to Iceland to help scientists at the Iceland GeoSurvey (ÍSOR) who cannot safely approach the volcano. Ramsey has been sharing the images with colleagues at ÍSOR and volcanologists worldwide.

Unlike standard weather-satellite images, the high-resolution pictures from ASTER can help scientists determine the plume’s chemical composition and thickness, the location of lava flows, and the volcano’s internal temperature, Ramsey explained. The data can help better monitor the volcano’s activity, particularly its worrisome effect on the nearby and much larger volcano Katla, which in the ASTER images is seen as a large off-color area to the right of Eyjafjallajökull. In the past, Katla has erupted every time Eyjafjallajökull has, though the ASTER images so far show no signs of an imminent explosion, Ramsey said.

Scientists study ‘glaciovolcanoes,’ mountains of fire and ice, in Iceland, British Columbia, US

The eruption in Iceland after it penetrated Eyjafjallajökull's icecap; new ash covers the glacier. - Credit: Marco Fulle
The eruption in Iceland after it penetrated Eyjafjallajökull’s icecap; new ash covers the glacier. – Credit: Marco Fulle

Glaciovolcanoes, they’re called, these rumbling mountains where the orange-red fire of magma meets the frozen blue of glaciers.

Iceland’s Eyjafjallajökull volcano, which erupted recently, is but one of these volcanoes. Others, such as Katla, Hekla and Askja in Iceland; Edziza in British Columbia, Canada; and Mount Rainier and Mount Redoubt in the U.S., are also glaciovolcanoes: volcanoes covered by ice.

“When an ice-covered volcano erupts, the interplay among molten magma, ice and meltwater can have catastrophic results,” says Sonia Esperanca, program director in the National Science Foundation (NSF)’s Division of Earth Sciences, which funds research on glaciovolcanoes.

In Iceland last week, scientists were well prepared for the floods, called “jökulhlaups,” that can happen after a glaciovolcano blows and melts its glacial covering. The floods were followed by tons of ash ejected into the atmosphere.

Most of the rest of the world, however, was unaware that an eruption from a small, northern island in the middle of the Atlantic Ocean could freeze air transportation and stop global commerce in its tracks.

That, say NSF-funded scientists Ben Edwards at Dickinson College and Ian Skilling at the University of Pittsburgh, is the nature of glaciovolcanoes.

Understanding volcano-ice interactions occupies much of Edwards’ and Skilling’s daily lives.

They’re working at Mt. Edziza in British Columbia, Canada, and in Iceland to find out how glaciovolcanic deposits–rock fragments strewn for miles after an ice-covered volcano erupts–are formed.

Volcano-ice interaction presents unique types of hazards, say the geologists, but what’s left behind after an eruption can also serve as a window into our geologic past.

Studies of glaciovolcanoes’ deposits are helping scientists get a better handle on Earth’s long-term climate cycles. The volcanic shards are “proxies” for climates of the past.

A key to using these rocks as proxies is the ability to correctly interpret fragmentation of lava and other textural and chemical features. From these, scientists estimate snow and ice thicknesses before and during a glaciovolcano’s eruption. The quantity of ash and flowing lava changes as the eruption progresses, until magma stops being formed.

Glaciovolcanic deposits are identifiable long after an eruption ends. Pillow lava, for example, which usually forms on the ocean floor, is sometimes found high atop mountains in British Columbia and Iceland, and in the Antarctic.

These round tubes of fossilized lava, coated with shiny black volcanic glass, are indications of volcanoes that once erupted beneath ice or water.

By noting the elevation of pillow lavas on mountains or high ridges, geologists can better determine the thickness of surrounding ice.

“Pillow lavas might well be forming right now in the ice-bound caverns on top of Eyjafjallajökull,” says Edwards. “By analyzing the gas content dissolved in pillow lavas’ glass, we can also estimate the thickness of the overlying ice at the time of their formation.”

When hot lava melts ice quickly, water can mix with magma, flash to steam, and produce powerful explosions of fine volcanic ash, according to Edwards.

“These fine particles can be carried much higher into the atmosphere than ash from similar ‘dry’ eruptions,” he says.

When superheated fragments of liquid magma hit cold air, they freeze into billions and billions of particles, driven into the atmosphere by the power of the volcano’s eruption.

“Although studies of glaciovolcanism are currently focused on longer-term questions of climate change, the research is helping scientists understand all active and dormant ice-covered volcanoes, including many in North America,” says Esperanca.

Several volcanoes in the Cascades, such as Mount Rainier, and volcanoes in Alaska, like the recently active Mount Redoubt, have significant ice cover.

Research on the links between these volcanoes and their ice-covered surfaces is giving scientists and emergency planners critical information.

“We need more studies of present and old eruptions to be prepared to respond to a volcano-ice crisis in North America–or elsewhere around the globe,” says Esperanca.

While many geologists are using Iceland as an important way to inform the public about possible dangers from volcanoes, glaciovolcanologists are chomping at their rock hammers–and ice chisels.

They’re waiting for Eyjafjallajökull to take a rest. Then they can creep ever closer, eventually getting a look at newly formed glaciovolcanic deposits.

To Edwards and Skilling, the eruption of Eyjafjallajökull shows how complex the dance of a volcano and a glacier can be.

Eyjafjallajökull ash cloud

After seismic activity in late 2009, Eyjafjallajökull volcano in Iceland began to erupt on 20 March 2010. On 14 April 2010, an eruption under the ice cap created a plume of ash which rose to altitudes used by jet aircraft. Beginning on 15 April 2010 the plume caused the closure of airports and major disruption to air travel across NW Europe and between Europe and N. America. The Special Session will discuss the volcanological setting, atmospheric transport and use of predictive modeling of the ash plume, and the palaeorecord of Icelandic eruptions affecting Europe’s climate and economy. A panel discussion will explore the implications and precautionary lessons for Iceland and Europe.

Speakers:

Thor Thordason on Eyjafjallajökull Volcanology;

Andreas Stohl and the NILU flexpart team on Eyjafjallajökull Ash Plume Transport;

Fred Prata on Wider implications for the airline industry of the Eyjafjallajökull event.


There is also a tentative talk, Iceland’s impact on Europe, now and in the recent past.

In addition to an hour of experts speaking, there will be a panel discussion on “Europe’s vulnerability to volcanic events”

Icelandic volcanoes can be unpredictable and dangerous

If history is any indication, the erupting volcano in Iceland and its immense ash plume could intensify, says a Texas A&M University researcher who has explored Icelandic volcanoes for the past 25 years.

Jay Miller, a research scientist in the Integrated Ocean Drilling Program who has made numerous trips to the region and studied there under a Fulbright grant, says the ash produced from Icelandic volcanoes can be a real killer, which is why hundreds of flights from Europe have been cancelled for fear of engine trouble.

“What happens is that the magma from the volcano is around 1,200 degrees and it hits the water there, which is near freezing,” he explains. “What is produced is a fine ash that actually has small pieces of glass in it, and it can very easily clog up a jet engine. If you were to inhale that ash, it would literally tear up your lungs.”

Miller says most volcanoes in Iceland erupt only about every five years on average and are relatively mild, but history is repeating itself. Extremely large eruptions occurred there in 934 A.D. and again in 1783 that covered Europe with ash much like today.

“Ben Franklin was ambassador to France in 1783 and he personally witnessed the large ash clouds over Europe, and he later wrote that it was a year in which there was no summer,” Miller adds. “The big question now is, what happens next? It’s very possible this eruption could last for quite some time, but no one knows for sure. Volcanoes in that part of the world are very hard to predict.”

Terra Satellite sees Iceland volcano’s ash moving into Germany

NASA's Terra satellite flew over the volcano on April 16 10:45 UTC (6:45 a.m. EDT) and the MODIS instrument captured a visible image of Eyjafjallajökull's ash plume (brown cloud) stretching from the UK (left) to Germany (right). -  NASA/MODIS Rapid Response Team
NASA’s Terra satellite flew over the volcano on April 16 10:45 UTC (6:45 a.m. EDT) and the MODIS instrument captured a visible image of Eyjafjallajökull’s ash plume (brown cloud) stretching from the UK (left) to Germany (right). – NASA/MODIS Rapid Response Team

NASA’s Terra satellite has captured another image of Iceland’s Eyjafjallajökull volcano ash cloud, now moving into Germany. Eyjafjallajökull continues to spew ash into the air and the ash clouds are still impacting air travel in Northern Europe.

NASA’s Terra satellite flew over the volcano on April 16 at 10:45 UTC (6:45 a.m. EDT) and the Moderate Resolution Imaging Spectroradiometer, or MODIS instrument aboard Terra captured a visible image of Eyjafjallajökull’s ash plume over the England and the Netherlands, stretching into Germany.

Air travel into and out of northern Europe has either been grounded or diverted because volcanic ash particles pose a risk of damage to airplane engines. NASA works with other agencies on using satellite observations to aid in the detection and monitoring of aviation hazards caused by volcanic ash. For more on this NASA program, visit: http://science.larc.nasa.gov/asap/research-ash.html.

The MODIS Rapid Response System was developed to provide daily satellite images of the Earth’s landmasses in near real time. True-color, photo-like imagery and false-color imagery are available within a few hours of being collected, making the system a valuable resource. The MODIS Rapid Response Team that generates the images is located at NASA’s Goddard Space Flight Center in Greenbelt, Md. For more information and a real-time MODIS image gallery, visit: http://rapidfire.sci.gsfc.nasa.gov/.