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Iceland Volcanos: Myths and Misunderstandings
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I have been seeing an increase in DOOM threads popping up on GLP about the recent volcanic eruption in Iceland all the way from, "OMG we're all doomed, the next ice age will
begin with this eruption" to "It's all a hoax, I don't see any ash"(ashtards!) so I would like to clear up a bunch of misinfo, misunderstandings, etc. So here we go...
Icelandic Volcanoes:
Iceland is one of the most active volcanic regions on Earth. It is estimated that 1/3 of the lava erupted since 1500 A.D. was produced in Iceland. Iceland has 35 volcanoes that have erupted in the last 10,000 years. On average, a volcano erupts there about every 5 years.
Eyjafjallajökull:
[link to en.wikipedia.org]
[link to en.wikipedia.org]
[link to www.volcano.si.edu]
For anyone confused about which Icelandic volcano is erupting right now, it is Eyjafjallajökull. Like other volcanos in Iceland this one is under a glacier of the same name. Although it is subglacial it's classified as a stratovolcano.
This current eruption is likely to be considered a VEI 3 event although it's always possible it could change if it continues to intensify. According to data by geologists and vulcanologists, it has erupted 4 times in the last 1100 years including the current eruption which began on March 20th of this year. The present eruption can last anywhere from days to months to years. The last time it erupted in 1821 it took almost 2 years to subside.
The current ash cloud is too high to be a risk to people on the ground and too thin to be seen, although it is likely to be causing sunsets to be redder because of the way the volcanic particles diffract the sunlight.
VEI(Volcanic Explosivity Index):
[link to en.wikipedia.org]
[link to volcanoes.usgs.gov]
Volcanic Ash:
[link to en.wikipedia.org]
Volcanic ash is like highly abrasive talcum powder. It's made of sharp fragments of rock that are capable of eroding plastic, metal and glass. Among other things, the fine particles can block fuel nozzles and stick to the turbine blades of aircraft engines causing them to stall.
There seems to be some confusion about which Icelandic volcano caused major doom in 1783. Some have said Katla and some have also mentioned Hekla but it is actually the Laki fissure eruption that is associated with the Mississippi River freezing, poison gas clouds over Europe and killing of up to 25% of the population of Iceland. Here is more info about all 3 of these volcanic systems.
Laki:
[link to en.wikipedia.org]
[link to iceland.vefur.is]
[link to www.volcano.si.edu]
Laki is a fissure in the south of Iceland that is part of a volcanic fissure system centering on the Grímsvötn volcano and including the Thórdarhyrna volcano. The Grímsvötn volcano is a Caldera. This volcanic system last erupted in 1783 for a period of 8 months and is rated a VEI 6 event, the eruption classification being Plinian/Ultra-Plinian. You can read more about the 1783 event in the link above or you can Google it.
*Can't find a webcam for this one*
Katla:
[link to en.wikipedia.org]
[link to iceland.vefur.is]
[link to www.volcano.si.edu]
The Katla volcano under the glacier Mýrdalsjökull which lies East of Eyjafjallajökull, is a subglacial volcano. According to records it has been set off by Eyjafjallajökull after the last 3 eruptions. Something to note however is that Katla has also erupted on it's own. In fact it has erupted 16 times since 930, the last major eruption having ocurred in 1918. The 1918 eruption was rated a VEI 5 event.
Katla Webcam: [link to www.ruv.is]
Hekla:
[link to en.wikipedia.org]
[link to iceland.vefur.is]
[link to www.volcano.si.edu]
Hekla is a composite or stratovolcano located in the south of Iceland and is Icelands most active volcano, the last eruption being in 2000. over 20 eruptions have occurred in and around this volcano since 874. Hekla VEI events have ranged from 3-5 historically. One of the largest since Iceland was settled is the Hekla 3 eruption in 1104 BC which is considered to be a VEI 5 event. The last eruption in 2000 was a VEI 3 event and was relatively short, lasting only 11 days. In a 1947 eruption ash fell as far away as Russia.
Hekla Webcam: [link to www.ruv.is]
All of these volcanoes show signs of possible eruption again in the near future. While they can all produce problems like what we are seeing with the present eruption, the main threat from Iceland would be Laki. The current eruption is minor in comparison.
Complete list of Iceland Volcanoes and their historical eruptions:
[link to en.wikipedia.org]
Large Holocene Eruptions:
[link to www.volcano.si.edu]
Note that that these are all > 4 VEI so Eyjafjallajökull, Katla and Hekla do not appear on this list. Hope this gives some perspective to the present eruption. For peeps in the USA, Mt. St. Helen's eruption in 1980 was a VEI 5 event.
Hoax? Ashtards?
There have been threads posted that say this is all a hoax since alot of peeps in Europe are not seeing any ash but rather beautiful blue skies. Rubbish! As noted above, the threat from ash is to airplanes not the majority of peeps on the ground. The ash is in the upper atmosphere where it can easily disrupt plane engines and pose quite a threat to air traffic. Here's a good Q&A about this issue and includes an answer to the question of why volcanic ash has not caused such a massive disruption of air traffic before:
[link to news.discovery.com]
And to the question of effects on air traffic from past volcanos including the Pinatubo eruption?
"...at least 10 Jumbo jets and 10 DC-10s suffered multiple engine failures in 1991 from ash from Mt. Pinatubo in the Philippines."
On the ground most people will not be able to see the ash since it has diluted so much, however some who have asthma and other breathing difficulties can be effected by it. It also depends where you are in the path of the ash cloud. Some areas are definitely seeing it accumulate on roads, cars, etc. Again, not everyone in Europe is necessarily going to be effected.
There are plenty of links to show where the ash cloud is blowing and who it will effect the most at any given time so just Google it or search GLP threads. Here's one link with an animation showing the movement of the ash cloud: [link to www.esa.int]
The more the eruption intensifies the more it will cause problems but who it will effect is up to where the jet stream carries the ash.
To the person who actually posted in a thread that the Eyjafjallajökull eruption is a hoax because of differing cloud colors observed, i.e. white and black clouds, the white clouds are the steam rising from the melting ice, basically the magma & water interacting(phreatomagmatic), and the black/grey clouds are from the magma or molten rock. It's very common for a large explosive eruption to have magmatic and phreatomagmatic components. Another geologist characterised it as a phreatoplinian style eruption.
While it is absolutely amazing to watch and it's certainly causing havoc for air traffic etc, this is not an uncommon event.
[link to www.earthmountainview.com]
Even if Katla were to erupt next, which is somewhat likely, it still would not be major doom like the Laki event or, God forbid, a Yellowstone supervolcano style event. It is most certainly NOT going to bring on a mini ice age. Let's reduce the woo-woo a bit and try and keep it all in perspective. 
***********Updated to add more links************
Live Volcano Webcam Threads by DailyDoom & AC 991571:
Thread: Live Volcano Web Cams And More!
Thread: Live Volcano Web Cams
Real-time aircraft traffic plus ash cloud movement:
(thanks to AC 944834)
[link to www.radarvirtuel.com]
some good reference maps:
[link to hraun.vedur.is]
[link to hraun.vedur.is]
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