Icelandic volcano update, and a comment on Joplin

We are all reminded of the sudden changes to plans that nature can enforce, at little notice. The eruption of the Grimsfjall/Loki volcano in Iceland continues, and there are now reports of animals beginning to die, as the ash continues to blanket the island. The ejection rate is running at around 1,000 to 2,000 tons per second, and the volcano is considered to be several times the power of last year's eruption. (It can be seen on web camera here). Airlines are allowed to fly, by UK regulation, where the ash density is less than 2 gm per 10 cubic meters of air.

Although the volcano is more powerful than last year's eruption, the magma is not shattering into as small a particle range as happened last year, the fragmentation comes when the hot magma meets the ice or water in the overlying glacier. But as the eruption continues the immediate overlying ice is all consumed, and without that the magma will flow as more conventional lava. The reducing availability of ice and water, even as the magma continues to flow, means that the problems that the ash cloud generates may be more transient than last year, where European airspace was closed for a week.

The threat to European Airspace 23 May 2011 (flight radar 24)

The cloud, which has closed Icelandic air space, is now approaching the UK, and has already caused President Obama to move his trip to the UK forward a day , so as not to be at risk from flying through the cloud. At present the cloud is close to Scotland, and it is expected that that airlines will cancel flights to affected airports. Some already have and the effects of the eruption could soon spread into Europe. However, with the changing ash size, as the water and ice is all used up, so there is hope that the ash plumes will decrease in size, and that Iceland may be able to open some airports as soon as tomorrow.

UPDATE: The picture above was taken late in the evening of the 23rd, the following picture is at around noon in the UK on the 24th, and flights are already being cancelled as the cloud becomes too dense at certain altitudes for planes to fly.



One of the questions, however, is as to whether the volcano may change from issuing from a single vent into a situation where the magma finds a second channel, which would put the second outlet back under ice, and give a secondary ash cloud. This might then spread south, giving a more continuous problem that would extend over time. The extrusion of magma from a series of vents along a fissure line is characteristic of the Laki eruptions which lie to the south of the current site.

While the impact of that natural event continues to unfold, the disaster in Joplin was there and gone in almost no time, with winds of up to 198 mph. I looked out of my window 150 miles East of there last night, and saw a storm coming in, gave it no more thought and went to bed. This morning I awoke to hear that 89 people had died, (now updated to 116) and that about a third of the city of 50,000 was destroyed. It is a city where many off the folk that work at KMT, a waterjet manufacturer in Baxter Springs KS, live and these include a number that have graduated and worked with me at MO S&T. Sadly I have heard already that three that I know as friends have lost their homes and all that they possess, and that of the six employees of the firm who did lose their homes, one also lost his wife.

Our thoughts and prayers are with them tonight.

An Icelandic volcanic eruption

Well this is interesting. I wrote a week ago about the pattern of earthquakes that was developing in the Mydralsjokull area of Iceland. However, earlier this year there was a growing pattern of earthquakes around the Grimsfjall region in Iceland, which is also known as the Loki volcano, There has now been an eruption in that region. And while the power of the volcano is already waning somewhat, there is some anticipation that the overall eruption might be larger than the Eyjafyallajokull eruption that happened last year, and the largest eruption at this site in over 100 years. At present the ash particles are being reported as larger than that from last year’s eruption, so that it likely won’t be as disruptive. It is also being blown northwest, and so does not threaten the main air corridors at the moment.

What makes it more interesting, and a little worrisome, however, is the line of strong earthquakes (i.e. above a level 3) that are shown by stars in the map below, and which run down from the current eruption towards Mydralsjokull, which is at the bottom. And these all happened in the last day. For convenience I have given the volcanoes their Norse names of Loki (which is where the current eruption is), Laki, which is the volcano that erupts along the line of the green stars, and Katla, which is the volcano at Myrdallsjokull. The largest of the earthquakes is a 4.6 and is down near Laki, rather than in the Loki region.

Recent earthquake activity in Iceland (Icelandic Met Office)

The recent low level of activity on the island (there hasn’t been a magnitude 3 since March, when usually there is one about every three days) suggests that there may be some energy to be relieved, and this might open one of the fissures at Laki. These are the big volcanoes which do bad things to air quality, not only in Iceland, but also often in Europe. We will have to see how this goes.

Iceland volcanoes and when can I travel?

Yikes! Flightradar has taken out their inclusion of the airports in the overall picture, and the emptiness of the European skies becomes even more apparent.

European skies at 12:48 pm CST

And so the next question comes as to how long will this last? And unfortunately the news there is not particularly encouraging. Even short flights through light ash from this eruption have already been shown to damage aircraft and so authorities are rightly going to be very conservative on what they allow. The backlog on passengers already caught in the cancellations are now up to more than a week.

Honeymooners Paul and Tracy Sheehan, of Kent, England, were among those trapped by the ashy atmosphere.

The couple arrived to catch a transfer flight on Friday night - only to hear the next available American Airlines flight home was one week away.

The hope that the volcano would have settled down enough to allow a scientific flight over the plume has been premature, and the flight was cancelled as the eruption continues.

Given that there is talk of other volcanoes erupting it might also be appropriate to go into a little more depth on the scale of these events. They are measured on a scale known as the Volcanic Explosivity Index (VEI) with values that can be read from this table:
Volcano Explosivity Index (from Rowlett UNC)

The initial measure for Eyjafjallajokull was at a scale of 1, but it hasn’t been possible to assess where it is now fitting. In contrast, as I noted Thursday when Katla last went it was at a scale of 5, and the Mount Pinatubo eruption in 1991 was a 6.

However Pinatubo was a single event eruption, ejecting some 15 – 30 million tons of sulfur dioxide, along with 5.5 cubic km of other material in a nine hour period on June 15th. The consequences lasted much longer.

The eruption plume of Mount Pinatubo's various gases and ash reached high into the atmosphere within two hours of the eruption, attaining an altitude of 34 km (21 miles) high and over 400 km (250 miles) wide. This eruption was the largest disturbance of the stratosphere since the eruption of Krakatau in 1883 (but ten times larger than Mount St. Helens in 1980). The aerosol cloud spread around the earth in two weeks and covered the planet within a year. During 1992 and 1993, the Ozone hole over Antarctica reached an unprecedented size.

The cloud over the earth reduced global temperatures. In 1992 and 1993, the average temperature in the Northern Hemisphere was reduced 0.5 to 0.6°C and the entire planet was cooled 0.4 to 0.5°C. The maximum reduction in global temperature occurred in August 1992 with a reduction of 0.73°C. The eruption is believed to have influenced such events as 1993 floods along the Mississippi river and the drought in the Sahel region of Africa. The United States experienced its third coldest and third wettest summer in 77 years during 1992.

Icelandic volcanoes are generally less immediately intense, spread over a longer fissure, and last much longer.

The initial fissure eruption at Eyjafjallajokull (AP)

Katla which is expected to possibly also erupt, last erupted in a major way in 1918, with 25 major eruptions in the last 1200 years. (Which gives an average interval of 48 years). These intervals are likely to continue, on average, given that the two plates that touch under Iceland are moving apart at a speed of around 19 mm/year. While this sounds as though it is a small amount, it puts the rock in tension, which makes it a lot easier for fluid such as magma to penetrate through flaws and fissures in the rock, as these open under that movement. It also helps explain why, on occasion, there is a progression of the eruption up a line, as we are currently seeing with Eyjafjallajokull. And given that there may be volcanic activity at different places, it might help to see where the different volcanic/separation zones are:

The EVZ, fissure swarms, central volcanoes and calderas. H and T denote the Hekla and Torfaj ̈okull central volcanoes. Focal mechanism and location of the 1987 Vatnafj ̈oll earthquake are from Bjarnason and Einarsson [1991].(Jonsson )

The Eastern Volcanic Zone (EVZ) shown above is thought to now be more dominant than the Western one, which has been relatively inactive, and it is here that the current crop of potential eruptive sources sit and that are being worried over. (Hekla for example has erupted in 1970 (VEI 3); 1980 (VEI 3); 1981 (VEI 2); 1991 (VEI 3); and 2000 (VEI 3).

So, given that the last Eyjafjallajokull eruption lasted over a year, and the length of time since the last Katla eruption, and the movement of the plates being relatively consistent, there is not a lot of room for optimism. It may not be an immediate follow-on in the human scale of time, but in geological terms a year later is almost such, so it may well be that the powers in Europe, and around the world, may have to rethink how folks can be moved, if air travel is going to be more of a hit and miss event for a couple of years. So will I get to Europe next week?