Canary Islands field trip

I never had any desire to visit these islands. My mental image has never been a complimentary one. I have to admit, after visiting: I was right. It is a tourist hell. Every single aspect of the towns seems to be directed at tourists.

But there is a single redeeming factor. If you like volcanology, like I do, it’s freaking awesome. Gran Canaria has the most awesome ignimbrites that I have ever seen or heard of. There was a time, where if you had been on that Island, you would have died. Melted down and formed part of an ignimbrite. The eruptions, in my imagination, are utterly epic and they probably don’t come close to the reality. Look at how happy I was studying those bad boys.2015-03-04 14.55.16

When a volcano erupts, there are two main (very broadly) types of eruptions: lava & pyroclastic. Lava, like we see in stromboli, Italy. Pyroclastic, like we see in Eyjafjallajökull, Iceland. On Gran Canaria, both have occured, but the pyroclastic eruptions are way way cooler in this situation.

Do you know what a Caldera is? It’s pretty sweet. It’s an eruption that is so strong, it has so much force, that it completely vacates it’s magma chamber and then it collapses in on itself, forming a crater. You get a series of ring faults along the margins of the Caldera where the collapse mainly occurs. In Gran Canaria, the ignimbrite has been hydrothermally altered around the caldera fault, resulting in some really beautiful views.

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The red, is oxidised, whilst the green is reduced. You can see the ignimbrite on the next mountain side in the photo. This does not show you how big the Caldera was, if you’re starting to think: huh that’s big. This Caldera is 15 km in diameter. It is not close to the largest. In Indonesia, lake Toba, there is a caldera that is 100 km in diameter. That’s a super volcano.

You would not want to be there during a Caldera Collapse.

The ignimbrite on Gran Canaria, which occurred around the same time as this Caldera collapse is found all over the island. This thing went for km’s. Just imagine, this primordial hell. Hot, like nothing else, and turbulent forces that would rip everything apart in its path. Blobs & bombs of magma flying in the air, flung across the breadth of the island. Just utter incomprehensible, destructive insanity.

At the base of the ignimbrites, most of them are not oxidised. This tells us that there was no oxygen when they were deposited. These eruptions were so violent, so turbulent, that oxygen couldn’t get in.

If you don’t think that that is awesome, don’t tell me. I will merely send you videos of volcanic eruptions until you change your mind. If you want videos of volcanic eruptions, I can oblige.

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You see in the above photo, there is a mouth shaped light coloured part, next to a tiny hammer? That hammer is about 30 cms. That shit was a bomb of magma during the eruption. Otherwise, that is called a fiamme. Beneath it, harder to see, is an 8 m long fiamme. What is fiamme you ask? Well! Fiamme is essentially collapsed pumice. What is pumice, say those who have never heard of volcanos? Pumice was lava, that cooled in the air. All the bubbles or vesicles in it are from gas escaping. After the ignimbrite gets deposited, sometimes they move afterwards. This stretches out and collapses the pumice.

So imagine a blob of gas rich lava, the size of a house, hurtling towards you.

Less educationally, here are some pretty pictures for you to look at:

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The gist of it all, is that I really truly love volcanoes. The more I learn about them, the cooler they are. If you ever visit this place; go inland. The inner sections of the island are absolutely gorgeous. The coast is pretty much horrendous and tacky.

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