Have you ever wanted to step inside a volcano? This summer a tour company is offering the chance of travelling down into the magma chamber/lava tube system/shallow magma storage area of Thrihnukagigur volcano. This volcano was talked about in a post by Erik from eruptions at some point last year. Whilst there is some controvesy over what to call the area beneath the volano, there is no doubt that an opportunity for the general public to explore a feature such as this is brilliant and is something I would love to do myself!
If any one can read Icelandic (which I can't I'm afraid!), there is a website here which gives some info and pictures and diagrams on the volcano and the area. There is some info on the volcano and the area in English here on the tour website. The video below gives a good overview of the size of the volcano and the gap underneath.
I can't comment with any certainty on the matter having not visited myself (its always best to look at things in the flesh and be there, you get a much clearer picture and can make clearer judgements for yourself!), however I am going to put my 2 cents in about the crater itself anyway.
As a cinder cone the type of activity at Thrihnukagigur volcano will be much like some of the episodes at Etna which have created cinder cones there over the years, and as such, present an interesting incite into processes below the surface during such events. The vivid colours inside the volcano demonstrate the high gas content and activity of the magma, further confirming the type of activity there. In certain volcanoes worldwide there are lava lakes and these can be seen to ebb and flow in height and activity, therefore we can accept that other volcanoes in similar situations will do this too and can often be seen as 'tide marks' of sort. It is certainly fortunate for us that the magma drained away (which there could be a few reasons why this happened) as we now have access to something quite beautiful and it does provide scope for research into the shallow plumbing systems of volcanoes.
A while back this tour was featured in a TV program (National Geographic) and yes while some of these shows can be sensationalist (not all of them!) one thing they do very well is promote interest in the science behind them and encourage people to investigate further so they are not necessarily a bad thing. There are a host of video and even the National Geographic program on the website which are worth a watch if you have some spare time!
Katla lies beneath the Mýrdalsjökull ice cap and has height of approximately 1512 m. Katla has been showing increasing signs of unrest for many months now with periods of harmonic tremor prompting news reports of an impending eruption. Also, historically, an eruption of the Eyjafjallajökull volcano is often followed by one at Katla.
However some of these news reports are citing the global impact an eruption may have. As a result I have a couple of comments about a recent BBC article titled New Icelandic Eruption Could Have Global Impact. First of all due to the high latitude of the volcano,a 'global impact' is unlikely, the majority of eruptions which transport ash globally and affect global temperatures are closer to the equator and if you look at past eruptions of Katla, the largest they reach is VEI 4/5 which is large, but not on the scale which Tambora or Pinatubo were. It is possible that ash will be transported through Europe again, although there are a number of factors which affect the transportation of ash other than wind direction, including ash particle size and strength of the eruption so even this isn't certain!
One of my main gripes, it is very unscientific and bad practice to say a volcano is overdue! Its seen with Yellowstone all the time, its not acceptable there so it isnt for Katla either!
Steam rising over the Mýrdalsjökull ice cap.
One of the major hazards from volcanoes such as Katla which lies beneath the Mýrdalsjökull ice cap is the jökulhlaup. These occur when an ice cap/glacier is heated from below, these events are usually triggered by a sub-glacial volcanic event. Such an event occurred on the 9th July from the Mýrdalsjökull ice cap and was likely trigger by an increase of heat flux from the caldera or a small sub-glacial eruption, this is a further indication of activity beneath the surface of Katla. There was also an episode of this kind in 1999.
I confess that I am not the first one to write about this, but I felt the point needed to be made that caution should be taken when reading articles making claims such as the BBC article.
So to summarise, Katla is showing signs of an eruption, with periods of harmonic tremor indicating the possible movement of magma beneath the caldera, however Katla will go when she wants to go!
The Vidgelmir lava tube is 2 km long and within a lava field approximately 52 km long, covering a total area of around 242 km2.It is one of a few lava tubes which are present within the Hallmundarhraun lava which was emplaced around 900 AD.The cave itself is unique for more than just its size, during the harsh Icelandic winters it forms beatuiful ice statalgtites/stalagmites which are said to hold families of ice elves! There are also very well preserved lava stalagtites further on into the cave. The reason that the tube is currently accesible is due to the collapse of the roof, giving the wide entrance which is seen in the photos!
For more information and photos, visit the tour website. If you are in Iceland I would certainly recommend a visit!
A quick couple photos to show the Eyjafjallajökull volcano and ice cap. On both photos it's very clear to see all the ash deposited on the surface of the ice from the eruption in 2010. Now it is a very beautiful and quiet place! Click on the photos to enlarge!
Below is a picture of the waterfall Svartifoss in the Skaftafell National Park, Iceland. A brief hike into the park and this wonderful waterfall appears in a valley out of nowhere. Similar formation can be seen at Fingal's Cave, Scotland and the Giant's causeway, Ireland. The basalt columns are formed by the contraction of hot rock as it is cooled, forming the amazingly geometric and regular shape.
Hi everybody, after a busy dissertation period and a trip to Iceland, I am back. Will be producing a few video features on Iceland in the coming few weeks, along with a few posts on some of the diversely intersting features of Iceland! These videos will be available here but also on my new Youtube channel. Below is a brief sample of Strokkur Geysir in Iceland, more to come including Seltun geothermal area. I will also be displaying pictures of the volcanoes of Iceland!
Grímsvötn, which is one of Iceland's most active volcanoes last erupted in 2004. The majority of Grímsvötn lies 200 m beneath the vast Vatnajökull ice-cap.
Due to its location beneath the ice-cap there are several signs of an impending eruption and the volcanoes unrest. Melting of the ice by hydrothermal activity often causes what the Icelandics call a jökulhlaup which is a glacial outburst flood. Melting of the ice can also cause depressions of the ice surface.
This 2011 episode started at ~17:30 UTC on the 21st May. Initially the eruption was contained benath the ice, but by ~21:00 UTC the eruptive cloud reached the surface and subsequently rose to an altitude of 20 km (~65,000 ft). It has currently closed the airspace in Iceland temporarily and a jökulhlaup is expected to be created as a result of the eruption.
Seismic activity indicates start of eruption after 17:30.
So....the big question is. Will this eruption disrupt the air traffic in Europe like the eruption of Eyjafjallajökull in 2010? The answer, currently, is probably not. The current simulations are predicting that the ash will travel to the east and then north. There are also some unconfirmed reports that the activity is 'slowing down'.
The following is a link to a webcam of the eruption, which may or may not be working!
An interesting fact about this volcano is that the Grimsvotn volcanic centre has fissures which trend through it NE to SW. One of these fissures is known as the Lake fissure, this fissure is renowned for its lava producing eruption of 1783 in which it released the the most lava seen and experienced by humans in recent history. It also released huge amoutns of Sulphur Dioxide causing an unusually hot summer for the time period. Overall, it caused widespread effects throughout Europe and is attributed to have killed ~30,000 people in Britain as a result.
I was shown this site a while back and just found the link for it again. A few brave volcanologists managed to get close enough to the vent of Eyjafjallajökull during the eruption in 2010 to take these amazing videos, below is an example but more can be found at http://www.mrietze.com/iceland10-2.htm. There are also some brilliant photos as well. Check it out!