This Is Not Just Any Volcano...

Not Geography Geography Lesson 14

Now This is Proper Geog!

Apologies for this week's blog being late once again, but my idea pool has been gradually drying up and I have just been enjoying languishing in my endless free time now that my exams are over. But, some rather over-exaggerated new stories drew my attention to this week's topic - super volcanoes, particularly Campi Flegrei in Italy, and volcano monitoring and prediction. 

Now That Is Some Proper Geography 

Volcanoes are probably one of the first things that people think of when they think of geography, and are honestly one of the most interesting topics in the subject; I actually wanted to be a volcanologist when I was growing up and came to University, only to realise how much maths is involved and I scuttled out of there like a rat up a drain pipe. 

Volcanoes are basically just channels or conduits where highly pressurized molten rock has found a weakness in the earth's layers and when the pressure has built enough, they blow all of that stuff up and out. 

Volcanoes are classified in a few of different ways:

*Quick side note : 'magma' is the molten rock, gas and liquid inside the volcano before eruption, it becomes 'lava' once it has escaped and is on the surface!

• Lava/Magma Type - depending on the type of plate boundary the volcano is formed on, there are four main types of lava/magma which range from super runny or Basaltic type, to super thick and viscous or Rhyolitic type.

• Volcano Shape - the kind of magma involved in the formation of the volcano determines whether the it will be either a classic steep-sided cone shape, or an almost flat shield shape, or somewhere in the middle ground. 

• Eruption Style or Length - depending again on the magma type, some volcanoes erupt very violently and even blow themselves apart (known as Plinian Eruptions), or some just flow very gently and nicely along the ground (such as Hawaiian Eruptions). 

What Makes This Volcano So Super Then?

Most people probably think of Yellowstone National Park when they hear 'super volcano' and they're not wrong. As a super volcano Yellowstone is an enormous series of connected magma chambers around 7km underneath the surface, which form what is called a Caldera - a large pool of magma under the surface formed where previous eruptions have blown all the rock out and then the magma has filled it. 

These kinds of volcanoes are 'super' purely because of their size, and hence their capacity for absolute destruction when they blow. We have yet to witness in modern history the impacts of a super volcano eruption, but it is estimated that when Yellowstone does erupt 1 in 7 of the global population will die as the gas and ash released will be so enormous that it will block the sun and we will all starve. Happy thoughts. 

But move over Yellowstone, because there is a new super volcano in town - Campi Flegrie, which sits under Naples in Italy. When I say 'new', it hasn't just formed recently or anything, but has only just made the news (and I say 'news' loosely because that includes the Daily Star and the Sun) because some things are starting to kick-off a bit over there. In fact scientists working there have said they fear the volcano is getting close to reaching "Critical Degassing Pressure", which is the point at which the pressure is so high, that all the liquids mixed in the magma start to return to gaseous state and form bubbles known as vesicules, which will force all the magma and everything out into an eruption. Just like when you drop your Fanta and open it too soon. 

So Is The Home Of Pizza And Pigeons About To Be Blown Off The Face Of The Earth?

Naples is one of most densely populated places on the planet, and approximately 500'000 people are living atop this fiery time bomb. Hence it could all go very badly wrong if this thing does decide to blow anytime soon; and rather helpfully scientists said in their assessment "There will be another super volcano eruption..." without actually saying when, which would be useful. 

Whilst the Sun makes it sound like any old Herbert could pop across to Italy, see the ground inflating and declare an imminent eruption, alas volcano monitoring is not that simple. The methods are predominantly looking at seismic signals which allude to rock cracking and magma rising beneath the surface, checking for miniscule changes in the height and width of the ground, and monitoring increases in gases and heat being given off. There are several 'lab volcanoes' around the world that are constantly monitored for these changes, and they have roughly taught volcanologists the signs of eruptions nearing.

 Unfortunately, it is by no means a predictable process with lots of false alarms and lots of random eruptions with no signs beforehand - volcanoes are sneaky and sometimes they will creep up out of nowhere, and sometimes they get bored halfway and go back to sleep. Just last year everyone started panicking because Yellowstone was unusually active (hint: it is always active), and all the animals started moving out, which is normally a very bad sign. All those Doomsday Prepper lunatics were rubbing their hands until it just stopped suddenly, and then they had to go back to stacking their 5000 toilet rolls in their basement. 

So Naples Is Safe For Now?

*Shrug* Most likely yes, but unless you're the real-life That's So Raven, no one can predict the future.We know that pressure builds over time, and more pressure means increased likelihood of eruption, but that relationship is not linear and so you cannot predict anything from it, other than the longer between the eruption the more likely they become generally. Campi Flegrei erupted on a small scale in the 1500's so is unlikely to go again any time soon. His American cousin erupted 640'000 years ago, but the pattern seems to indicate an eruption every 1 million-ish years, so we have a good 350'000 years to wait potentially. 

Whilst I would be more than happy for thousands of Italian pigeons to be instantly incinerated, it seems highly unlikely at the mo'; despite what the Sun says. Hopefully you enjoyed this week's proper geog topic, because stuff blowing up is always exciting. See you next week!

P.S - Please also appreciate how straight-forward and epic sign language is, as evidence in the Gif below:

Dead Dinosaurs and Underwater Abysses

Not Geography Geography Lesson 13

Dead Dinosaurs and Underwater Abysses 

Apologies that it has been many, many weeks since I have posted but I had to revise for exams for my actual degree so that I can afford to buy several dogs when I'm a real adult. But now I'm back, with a blog - inspired by Chris Packham of all people - about the Chicxulub meteor impact and the formation of the Yucatan's 'Ring of Cenotes'. 

Chicxulub Is A Weird Word

Chicxulub is actually Maya for 'tail of the devil', taken from the native language of the Yucatan where the meteor struck approximately 65 million years ago,  marking the end of the Cretaceous period of history. It is estimated to be the biggest meteor to ever have impacted our planet, measuring a rather mind-boggling 100km in diameter, and creating a crater nearly double that size. The impact was the equivalent of 100 megatons of TNT and not surprisingly then, it also marked the end of the dinosaurs. The ones which were not directly killed by the impact, the enormous tsunami it generated, or the fact that everything within hundreds of miles was on fire, were killed by the change in climate caused by the ash and particulate matter thrown into the atmosphere blocking the sun. If you have seen Walking With Dinosaurs then you will know that it was the season finale of nightmares.  

Researchers only discovered the crater in 1991, which seems strange because I think even I, who is the worst 'dad-looker' in the world and regularly can't find the milk in the fridge, would notice a 200km impact crater. But over time it has been buried under over a kilometer of sediment, and was originally thought to be an ancient volcano. Only when examining material for boreholes at the site and scanning it with RADAR did researchers realise something very big and very bad had happened.

Cenotes Is Also A Weird Word

A cenote is a large freshwater sinkhole up to 100m deep, formed by the erosion of limestone rock by acidic groundwater. The word is taken from Maya for 'well' (not as exciting as 'tail of the devil'...). There are over 6000 cenotes of various sizes in the Yucatan Peninsula of SE Mexico, and have been utilised as a vital water source for thousands of years by the areas populations. They are also super beautiful features, in a 'very lovely to look at but all kinds of horrible beasts are probably lurking in there and I will stay on the ground thanks' kind of way. 

Only in the past century have scientists begun exploring and documenting the cenotes, and who can really blame them for avoid swimming into the abyss.... But they have found that the water in the cenotes is not actually still, and is flowing very very slowly into other cenotes, meaning that they are all connected by an enormous network of underground caves. They could be one of the largest and most intricate karstic (systems created by acidic erosion of limestone rock) systems in the world. Scientists have also found sacrificial items including gold, jewelry, figurines and human skeletons in the cenotes, which supports evidence that the Mayan civilisation associated them with powerful gods, and had strong cultural connections to the wells. 

How Is Chicxulub Connected To The Cenotes?

There are 900 cenotes of particular interest to scientists, which are all located along the Southern rim of Chicxulub crater. They believe that the rim and side of the crater created a barrier which trapped groundwater and forced it back into the rock, encouraging erosion and the formation of the cenotes. Hence being named the Ring of Cenotes.  

Hence, without the meteor there would be no crater and no cenotes in that area, and the native populations would have been unable to survive. So on one hand the meteor wiped out the dinosaurs and nearly every living thing on Earth, but also facilitated the creation of these amazing and terrifying freshwater wells; give and take then. 

So far only a handful of the ring have been fully mapped and explored, but they already are appearing to be highly important for the survival of surrounding ecosystems and boast an enormous variety of biodiversity (another reason to admire from the surface in my book). I hope you enjoyed this rather delayed post, and see you next week!