19 April 2010


Thats the big volcano thats erupting in Iceland at present, and causing such chaos around the world.
How could a Geologist not write about it!

So, according to Wikipedia, this volcano has been active on and off for the last thousand years, but this event started rumbling in 2009, with the first eruption on the 20th March 2010. That one just cause 500 people problems. When it erupted again on the 14th April, the amount of ash it has thrown up into the atmosphere has grounded planes all over europe, backing up air passengers all over the world. And suddenly the world has realised just how reliant we have become on air travel! (image is the ash cloud on  17th April 2010)

So, whats actually going on?

Well. We all know about volcanoes, right? Rock, so hot that its not solid any more, works its way to the surface because its less dense than its surroundings, and escapes at the top. Kind of like the way oil sits on water.

Now sometimes this is a nice smooth process. It all depends on the chemistry of the rocks. But places like Hawaii have really runny lava that erupts nice and easily, whereas volcanoes like Mt Etna, in Italy, have very sticky, thick, only just about liquid lava which doesn't escape as easily. As this kind of lava gets to the surface, all the gasses in it expand due to the drop in pressure at the surface. And BANG! It blows the lava to pieces and results in very explosive eruptions.

Now, the Iceland volcano is different again. Icelandic lava is pretty runny in general, but in this case the volcano is erupting under a glacier.

Hot lava + cold ice = water = explosions

Why? Ever made the very dangerous mistake of throwing water onto burning oil? It doesn't end well. The water flashes to steam and expands explosively, taking the burning oil with it and causing horrific fire balls (see picture!)

The same happens to the lava- when the molten ice mixes with the molten rock, the rock freezes instantly into a "glass"[i.e. solidifies so quickly its atoms can't get into a set structure kind of like with glass] and the ice flashes explosively to steam, explosively dispersing tiny little fragments of glass into the upper atmosphere.

Which then gets into plane engines and stops them from working and risks the plane dropping out of the sky.

What I find really amusing is that people are talking it personally, and expecting the government to drop everything and get them to where they need to be. It’s a
also known as an 
Act of God. 
Its no ones fault! No one can fix it or make it go away any faster. The volcano isn’t out to make your life harder. Its just doing what it does! Its costing the economy a huge ammount, they inevitably means its costing lots of people lots of money. But hey! You're stuck on holiday. Things could be worse.

I know, its not currently affecting me personally, but it might. Last time it erupted, it went on for two years. Hopefully it will boil off all the water and then hopefully the explosivity of the eruption will drop. But I've read a few reports of a "more sticky" lava coming up, so we'll see.
I'm flying home on the 3rd June. So fingers crossed it'll have died down by then. But if it hasn't, I don't expect the government to sail a ship over here to get me home.

Oh, and fingers crossed for Al- his ultra marathon is due to finish 3km from the volcano. Fingers crossed all his training won't go to waste!

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