State College, PA 4/21/2010 11:41:48 PM
News / Nature

Ash Cloud Crisis Over, For Now

AccuWeather.com reports the majority of airspace across Europe has reopened after a six-day shut down due to an Icelandic volcano eruption, and it appears the threat to aviation is over for now.

 

The volcano has reentered a quieter stage currently, after a calm phase on March 20, and a violent-eruptive stage occurring on April 12.

 

"It's gone through three phases where we think it is going to stop, and the events have mitigated around the volcano," said Peter La Femina, Associate Professor of Geosciences at the Pennsylvania State University.

 

However, scientists note that Eyjafjallajokull could keep erupting, but a time frame for cessation is relatively unknown.

 

"Currently, the seismicity shows that there's still magma migrating through the system," said La Femina. "It could go on for a year, it could stop tomorrow. We just don't know."

 

La Femina explained that it is not uncommon for volcanoes to erupt for years, and the Icelandic volcano is of no exception.

"During the last eruption of Eyjafjnallajokull in 1821, the eruption actually lasted from 1821 to 1823," he said.

 

While the London Volcanic Ash Advisory Center announced in its latest warning that there is "eruption continuing" from Eyjafjallajokull, volcanologists in Iceland said the volcano's ash output has been decreased by 80 percent since April 14.

 

Icelandic scientists also report that any ash content spewing for the volcano is "insignificant," which could have caused aviation officials to resume flights Wednesday.

 

Aviation officials report that as many as 95,000 flights have been canceled since Thursday, when much of Europe's airspace was initially closed.

Why Did Icelandic Volcano Wreak Havoc on Aviation?

 

In light of the recent Icelandic volcano eruption that is responsible for one of the most costly and widespread aviation crises on record, how was this volcano able to cause such a travel nightmare?

 

Eyjafjallajokull's ash plume stalled aviation over Europe for more than five days because of the interaction between ice and lava during the eruption, as well as the lava composition, which is unique and influenced by the country's glacial nature.

 

Eyjafjnallajokull is a subglacial volcano, meaning the eruption occurs beneath the surface of an ice sheet. The heat of the lava from these volcanoes has the power to melt overlying ice, making lava flow much more easily.

 

"The eruption did migrate to be subglacial, and that interaction with the glacial ice has been more explosive through fragmentation of the lavas," explained La Femina.

 

The volcano erupted in separate phases, with the first relatively calm phase taking place on March 20.

 

However, the eruptions within the second phase occurring on April 12 were much more violent and spewed out a much different type of lava than the previous phase did.

 

This dramatic change in eruption was possible because volcanoes emit lava of different consistencies, but predicting what type of consistency will result from an eruption is difficult.

 

The interaction between the lava and the surrounding ice gives off steam, which propels ash more explosively than the slow-moving, shallow eruptions as exhibited by Hawaiian volcanoes.

 

Steam-powered explosions can propel ash thousands of feet into the Earth's atmosphere, and in Eyjafjallajokull's case, ash clouds were spewed up to 30,000 feet into the air.

 

These powerful steam-powered eruptions shatter the magma into very fine ash, and those ash particles are easily dispersed both upwards and outwards in the atmosphere and can remain airborne for long periods of time.

 

The atmospheric winds also enabled ash dispersion, carrying the fine particles from Eyjafjallajokull and extending across much of Europe.

 

However, La Femina said it is very difficult to predict ash dispersion levels after individual eruptions.

The uncertainty of the direction of the ash plume combined with the dangerous nature of ash itself were contributing factors to the closure of European airspace.

 

"When you have a volcanic eruption, especially when it's so highly explosive, you're fragmenting the lava down to individual glass shards," explained La Femina.

 

The problem arises when the particulate material interacts with modern jet engines.

 

"The temperatures within the jets can actually melt that glass and fuse it to the turbines," he said. "It basically causes the engines to stall."

 

Although eruptions are easier to forecast through the use of seismic equipment, it is inaccurate to assume the concentration of lava spewing from a volcano will be of a particular consistency.

 

Ultimately, scientists cannot predict whether or not the same very fine ash will continue to spew from Eyjafjallajokull, or if only a steam cloud including no particulate matter and no risk to aviation will erupt.The majority of airspace across Europe has reopened after a six-day shut down due to an Icelandic volcano eruption, and it appears the threat to aviation is over for now.

 

The volcano has reentered a quieter stage currently, after a calm phase on March 20, and a violent-eruptive stage occurring on April 12.

"It's gone through three phases where we think it is going to stop, and the events have mitigated around the volcano," said Peter La Femina, Associate Professor of Geosciences at the Pennsylvania State University.

 

However, scientists note that Eyjafjallajokull could keep erupting, but a time frame for cessation is relatively unknown.

"Currently, the seismicity shows that there's still magma migrating through the system," said La Femina. "It could go on for a year, it could stop tomorrow. We just don't know."

 

La Femina explained that it is not uncommon for volcanoes to erupt for years, and the Icelandic volcano is of no exception.

"During the last eruption of Eyjafjnallajokull in 1821, the eruption actually lasted from 1821 to 1823," he said.

 

While the London Volcanic Ash Advisory Center announced in its latest warning that there is "eruption continuing" from Eyjafjallajokull, volcanologists in Iceland said the volcano's ash output has been decreased by 80 percent since April 14.

 

Icelandic scientists also report that any ash content spewing for the volcano is "insignificant," which could have caused aviation officials to resume flights Wednesday.

 

Aviation officials report that as many as 95,000 flights have been canceled since Thursday, when much of Europe's airspace was initially closed.

Why Did Icelandic Volcano Wreak Havoc on Aviation?

 

In light of the recent Icelandic volcano eruption that is responsible for one of the most costly and widespread aviation crises on record, how was this volcano able to cause such a travel nightmare?

 

Eyjafjallajokull's ash plume stalled aviation over Europe for more than five days because of the interaction between ice and lava during the eruption, as well as the lava composition, which is unique and influenced by the country's glacial nature.

 

Eyjafjnallajokull is a subglacial volcano, meaning the eruption occurs beneath the surface of an ice sheet. The heat of the lava from these volcanoes has the power to melt overlying ice, making lava flow much more easily.

 

"The eruption did migrate to be subglacial, and that interaction with the glacial ice has been more explosive through fragmentation of the lavas," explained La Femina.

 

The volcano erupted in separate phases, with the first relatively calm phase taking place on March 20.

 

However, the eruptions within the second phase occurring on April 12 were much more violent and spewed out a much different type of lava than the previous phase did.

 

This dramatic change in eruption was possible because volcanoes emit lava of different consistencies, but predicting what type of consistency will result from an eruption is difficult.

 

The interaction between the lava and the surrounding ice gives off steam, which propels ash more explosively than the slow-moving, shallow eruptions as exhibited by Hawaiian volcanoes.

 

Steam-powered explosions can propel ash thousands of feet into the Earth's atmosphere, and in Eyjafjallajokull's case, ash clouds were spewed up to 30,000 feet into the air.

 

These powerful steam-powered eruptions shatter the magma into very fine ash, and those ash particles are easily dispersed both upwards and outwards in the atmosphere and can remain airborne for long periods of time.

 

The atmospheric winds also enabled ash dispersion, carrying the fine particles from Eyjafjallajokull and extending across much of Europe.

 

However, La Femina said it is very difficult to predict ash dispersion levels after individual eruptions.

The uncertainty of the direction of the ash plume combined with the dangerous nature of ash itself were contributing factors to the closure of European airspace.

 

"When you have a volcanic eruption, especially when it's so highly explosive, you're fragmenting the lava down to individual glass shards," explained La Femina.

 

The problem arises when the particulate material interacts with modern jet engines.

 

"The temperatures within the jets can actually melt that glass and fuse it to the turbines," he said. "It basically causes the engines to stall."

 

Although eruptions are easier to forecast through the use of seismic equipment, it is inaccurate to assume the concentration of lava spewing from a volcano will be of a particular consistency.

 

Ultimately, scientists cannot predict whether or not the same very fine ash will continue to spew from Eyjafjallajokull, or if only a steam cloud including no particulate matter and no risk to aviation will erupt.

 

By AccuWeather.com writers Gina Cherundolo, Jon Auciello, & Carly Porter

 

If you have questions or want to speak to a meteorologist, contact:

Roberti@AccuWeather.com

 

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