Venting About Volcanoes

As our lives increasingly shift online, and computers continue to take over the planet, hackers and spammers and other dodgy operators are finding progressively more ingenious ways to separate us from our cash. And their latest ruse is to steal your electricity; not directly - but, instead, by getting your computer doing lots of power-hungry complicated calculations, the results of which they then sell to make money for themselves leaving you pay the power bill. And they’re hiding the system that does this in normal webpages and even online adverts so it’s really easy to fall victim without even realising. They call it “cryptojacking” and Chris Smith spoke to Chris Folkerd from web hosting company UKFast...

Chris F - My name is Chris Folkard. I’m the Director of Enterprise Technology here at UKFast.

Cryptojacking is the latest trend. Last year we saw a lot of cryptolocker where people were using cryptography to lock people’s machines and then extract payment. This year it’s changed to using their computers to generate money automatically rather than trying to get customers to pay.

Chris S - So this is the whole concept of mining for Bitcoins isn’t it?

Chris F - Yes.

Chris S - I suppose we should explain first of all what actually is cryptocurrency and how does it work?

Chris F - Cryptocurrency has been around for the last ten odd years and it’s a different way of representing currency. Traditionally it’s gold coins, it was something that you could handle. Nowadays people are moving to a more electronic form. There’s no inherent value to cryptocurrency; it’s got a value because people have decided it does. And all it is is a small package of information that can uniquely prove as yours and you can subdivide and trade with other people, and that’s all done with cryptography.

Chris S - Where do you get Bitcoins from? How are they made or minted?

Chris F - The easiest way for people to get them is to now buy them online. There’s exchanges where you can by your cryptocurrency. All they are is, effectively, a payment from a computer as a thank you for processing some work. So a Bitcoin is known as a distributed ledger, so it’s basically an account book and your PC will get a thank you for processing a part of that ledger and validating that it’s true. But as there’s more devices mining for it the maths behind it gets harder and harder so the value goes up because you have to do a lot more work to get the same reward.

Chris S - One statistic I saw was that actually mining for Bitcoins - so doing these computer calculations - leads to emissions of more CO2 from data centres than the whole of the country of Ireland!

Chris F - There’s been a lot of speculation around that. It certainly is a CO2 intensive operation. If you look at people who are doing it semi-professionally nowadays, they have extremely large numbers of arrays that are doing calculations all the time and that does utilise a huge amount of electricity.

Chris S - So if you can’t afford to either meet that electricity bill, build a big enough computer, or run a big enough computer the simple answer is you basically steal someone else’s computer indirectly via planting something on their machine that does those calculations on their machine without them knowing and does the work for you and sends you the results. Is that basically what’s happening?

Chris F - Yeah, pretty much. The electricity costs are now at a point where there is a tradeoff between whether it’s actually worth mining some of these currencies. So now it is very much use someone else’s resources, steal their electricity and then get the coin for free.

Chris S - How are people doing this?

Chris F - There’s two main methods that people have started to adopt. They are getting you to open an email that opens up an application that cryptomines, and that sits in the background on your PC doing that. Most people don’t notice it other than the fact it will slow your PC down. There’s now a trend in the last six months to doing it in browser, and this is the bit that’s got slightly more troublesome because it’s so easy to exploit.  And that is where websites are installing something called “Javascript.” It’s a bit of software inside their webpage that runs in the background and it uses your spare CPU cycles to generate the coin for them.

Chris S - Oh god, that’s really sneaky! So by visiting a website you don’t even realise you’re actually trying to earn some money for the website owner and it’s basically your electricity bill that’s paying for that?

Chris F - Yep. Recent scans of the web found about 33,000 sites already, and that’s just well known sites that have started doing it in the background...

Chris S - Wow! When you say “well known” as in the kinds of sites that your average web user would visit?

Chris F - Yeah. They’re not necessarily going to be the high brand name ones, but a lot of the ones where you’re getting content for free. So free services are sometimes now subsidising themselves with some coin mining.

Chris S - And it doesn’t compromise the website performance?

Chris F - It does. And that’s where a lot of users are pushing back. There’s been some instances where it’s been the website owner that’s been publishing the Javascript, and that has had an impact. It can dramatically slow down not just your browsing experience for that, but if you’ve got any other tabs open as well, them as well. But what we’ve also seen is some people surreptitiously putting them into adverts. So the ones that pop up on your webpage, they will be doing the mining but it drags the performance of the main website down as well. And that can be unknown to the website owner because they’re not necessarily controlling their adverts.

Chris S - How would a person listening to this diagnose that they may have this problem?

Chris F - The biggest telltale sign is your PC will slow down. Unfortunately, that’s not unique to cryptojacking, that could be anything. But if you notice that everything’s started to run very slowly, either when you’ve got specific tabs open or where you've got an application open you can just go into “task manager” have a look at your CPU and it will show that it’s pegged at 100 per cent.

Chris S - Is it relatively easy to treat?

Chris F - Yes. That’s the good news is that a lot of the cases that are out there now are easily picked up by antivirus software. They will either block it automatically or tell you that the threats’ present; at the same time it stops these problems...

How does a material developed for NASA spacesuits get onto stadium roofs back here on Earth? Here's Stuart Higgins...

Stuart - What happens when the science and technology of space comes Down to Earth?

Welcome to Down to Earth from the Naked Scientists. The mini series that explores the spinoffs from space technology that are being used on Earth. I’m Doctor Stuart Higgins.

This episode: how materials used in spacesuits developed for NASA for the Apollo missions continue to be used in stadium roofs around the world.

January 27th, 1967. A fire breaks out during testing of the Apollo I command module. The first of the missions aiming to take astronauts to the moon. Spreading rapidly through the flammable materials inside the spacecraft the fire kills the three astronauts onboard.

The tragedy led NASA to search for new fireproof materials for their spacesuits. Nylon had been used throughout the command module but had melted during the fire and the existing spacesuits failed to provide adequate protection.

A solution was proposed by two companies working with NASA. A new kind of fabric based upon woven glass fibre and coated with a non-stick plastic polytetrafluoroethylene, otherwise known as teflon. The called the new material “Beta Cloth” and it formed the outer shell of the updated spacesuits giving ten times greater fire resistance compared to what had been before.

And while spacesuit materials have moved on since the Apollo era, beta cloth found a new lease of life back on Earth as construction material. Walter Bird, an aeronautical engineer, realised the potential of beta cloth as an architectural building material, and in 1956, formed a company to take the tech further. The company specialises in tensile structures where the building materials are continuously held in constant tension.

They’re most commonly seen today as the curving tent-like roofs on structures like the O2 stadium in London, and many other sports stadiums around the world.  The tightly woven glass fibres give the material its structural integrity, while the teflon coating reduces the ability of dirt and grime to stick to the roof allowing most of it to wash off when it rains.

The teflon polymer is made up of a long chain of carbon atoms each attached to atoms of fluorine. The configuration of electrons in the fluorine atom make it highly electronegative meaning it can strongly attract other electrons towards it. It’s the incredibly strong bond between carbon and fluorine atoms in the plastic that gives the useful non-stick properties.

Also when used in beta cloth, teflon’s white colour has the advantage of helping to reflect sunlight stopping things getting too warm inside buildings. The flexibility and strength of the material, along with its rapid installation, allows architects to explore different and interesting designs in their structures and has furthered its use.

So that's how a material originally developed for spacesuits for Apollo astronauts has become a widespread building material throughout the world.

Volcanoes have been in the news a lot recently, with eruptions in Hawaii and Guatemala; so this week we’re taking a look at the impact that volcanoes and eruptions can have on the environment, technology and our lives. Chris Smith spoke to volcanologist Jessica Johnson from University of East Anglia for a quick 101; what actually is a volcano? 

Jess - A volcano happens because there is magma under the ground. Magma is made up of molten rock and gas and small crystals of rock, and that magma is going to be less dense than the surrounding crust, the surrounding rock, and because it’s less dense it tries to get to the surface. Once it gets to the surface it erupts as lava, as an explosion of gas, ash, and that’s what we call an eruption of a volcano.

Chris - What powers a volcano? Where does it get this heat from?

Jess - The thing that’s actually causing the magma, the melting of the rock,t could be due to decompression. Where the rock is coming to the surface it has less pressure on top of it and that causes it to melt. Or it could be a chemical reaction with the addition of water. When you add water to a rock it lowers the melting point and that might melt the rock. Or it might be a bit hotter than the surrounding area and that might also melt the rock.

Chris - Apart from the hot rock that we can see, what else is issuing that we can’t?

Jess - Mostly gases. There are lots of different gases that come out of the magma at different depths as well. The gases that we usually associate with the eruptions are carbon dioxide, sulphur dioxide, steam. And then if it’s an explosive eruption you might have tiny particles of the lava, which we call ash as well so that would also be caught up in the plume.

Chris - How do those gases get in there in the first place?

Jess - The gases are dissolved in the rocks and as the rocks melt and become less pressurised as they rise through the crust, different types of gases will come out of solution at different depths. So by looking at the gases we can tell how deep the magma is.

Chris - Why do volcanoes happen where they happen?

Jess - The Earth has a thin crust on the outside, which is what we live on. And that crust is split up into plates, which we call “tectonic plates” and they move around on the surface of the Earth. They move slowly, but some places they’re moving apart, some places they’re moving together, and some places they’re moving side to side. At places where they move toward each other or apart from each other, that’s where we’re likely to get volcanoes.

Chris - What triggers them to go off?

Jess - That’s a very good question. We don’t know exactly what causes an eruption to start when it does, but we do know that there are some triggers; for example if there’s a new batch of magma that gets pushed into the magma reservoir, that can cause a chemical reaction. Ultimately, gas is what drives most eruptions. If there is gas trapped under the ground then it will try to get out and that’s what causes an eruption.

Chris - How good are we at predicting or forecasting when an eruption might happen?

Jess - We’re okay. We’re getting better. We monitor volcanoes, particularly volcanoes that are near populated areas with seismographs, which measure motion of the ground. And so what we’re looking for there are small earthquakes because when the magma’s pushing its way through the rock, it will crack the rock and cause lots of small earthquakes so if we can monitor where those earthquakes are we can tell where the magma’s going. That magma might also deform the surface of the ground and so we can monitor that with satellites.

Chris - You can see that can you?

Jess - Yes you can. Absolutely. In fact, in Hawaii right now the surface of the caldera, because this magma has been withdrawn from the summit it’s subsided by tens of metres.

Chris - Really. So you can actually physically measure the ground buckling and changing shape...

Jess - Absolutely.

Chris - … as the magma moves in and out?

Jess - Yes, absolutely.

Chris - And those movements are then used to make predictions?

Jess - Yeah.

Chris - Anything else you can look for? What about gases coming out because if you’ve got magma and things moving, presumably the gas composition could change and you could look at that?

Jess - Yes, absolutely. As I said before, because the different gases come out of solution at different depths we can look at how much gas, which gas, and where those gases are coming out to tell us where the magma’s moving.

Chris - And what happened in Hawaii? Is that comparable with what happened in Guatemala?

Jess - Not really. It’s the same that there is magma underground that is trying to get out but they’re two very different volcanoes. In Hawaii, the magma is a lot runnier and a lot hotter; that allows the gas to escape and it allows the lava, once it’s out of the ground, to continue to be runny which means that we don’t get so many explosions.

Whereas in Guatemala, it’s a different type of volcano caused by water being dissolved into the rock and that’s what’s causing the magma and so there is more gas, the lava’s very sticky and that’s why the gas can’t escape, and pressure builds up and that’s why we get a big explosion. This sort of activity, volcanoes are quite local processes. There aren’t any connections between these two volcanoes.

Many of us remember being stuck and grounded in 2010, very long queues at airports with no-one going anywhere. In fact, it became the largest global air traffic shut down since World War II, and it happened because of an Icelandic volcano called Eyjafjallajökull. The ash from volcanic eruptions can cause catastrophic damage to aircraft engines. But how? And what can we do about it? Chris Smith spoke to Anna Young from the Whittle Lab in Cambridge University, and later Izzie Clarke spoke to the University of East Anglia's Jessica Johnson. Firstly, Chris asked, why is sand a problem for engines?

Anna - Basically, the ash is sand and sand can cause quite a lot of damage to the engine on its own, in the first place. But, because of its larger surface area, it can melt more easily and when it turns into glass in the hot parts of the engine that can cause really really big problems.

Chris - These are jet engines that we’re dealing with here, that’s what you work on. So can you just explain for people who are not familiar just explain very briefly how a jet engine works?

Anna - Sure. When you’re walking up to your plane the part you can see is the fan -  big set of spinning blades. And the job of the fan is to pull the air into the engine and about 90 percent of the air goes through the fan and then out through the nozzle at the back where it’s pushed out quickly, and that jet going backwards creates thrust to drive the engine forward.

Now the job of the rest of the engine is to use the other 10 percent of the air to drive the fan. So the air that’s not gone through the bypass goes into the compressor where it gets squeezed to a much higher pressure. And then it goes into the combustion chamber where we burn fuel to add energy.

Next we’ve got hot, high-pressure air and that goes through the turbine, which is another set of spinning blades that takes energy out of the air and uses that energy to spin the fan and the compressor. So the turbine uses hot air to drive the fan which produces thrust to drive the engine.

Chris - I went to a talk by someone from Rolls Royce and they summarised and said it’s suck, squeeze, bang, blow. It sucks air in at the front, squeezes it very hard and gets it hot, chucks a load of fuel in which burns, and then they extract energy at the back end having blown the gas stream out to then drive that fan. But I suppose one should point out that the gas stream in there is at very high temperature isn’t it? It’s like 1500 degrees C inside the engine when the fuel’s burning?

Anna - Yeah. At the entrance to the turbine the air is, as you say, about 1500 degrees, and that is hotter than the melting point of the turbine blades.

Chris - The engine’s running at a temperature beyond its melting point, so why doesn’t it melt?

Anna - What we do is we take some air from a cooler part of the engine from part way through the compressor, and we drill tiny little holes in the turbine blades and we blow that cool air through. That cool air creates a film that keeps the turbine just under its melting point basically.

Chris - Ah. So you’re protecting the surface of the blades with a very thin cushion of slightly cooler air so any incoming gases are sort of going to ride over the blade without touching it.

Anna - Yep.

Chris - If I chuck in whole bunch of sand and volcanic dust, what does that do to the system?

Anna - It’s likely to turn to glass because as well as being hotter than the melting point of the turbine blades, that part of the engine is hotter than the melting point of the ash. So we get glass which clogs up all of those little holes and then we  won’t have any cooling air and the turbine will melt.

Chris - Then you get a sort of ‘hot spot’ on the blade, and what will that do cause it to weaken or change shape, deform, distort?

Anna - Yeah. I think it’ll happen pretty quickly at that point and the blades will start melting so then you haven’t got a turbine to drive your fan. The other thing that happens is that air has to go somewhere, and where all the air from the rest of the compressor goes is the combustion chamber. So we have the wrong mix of fuel and air, so that can make the fire in the combustion chamber go out and then you’ve basically switched your engine off.

Chris - And then you lose power catastrophically?

Anna - Yeah.

Chris - Given that we know this, what can aircraft operators do to minimise the damage to their engines - just not fly?

Anna - Essentially, yes. In my lab we spend a lot of time simulating the flow of air through the engine. You could do that and people have done it where you add in the flow of the sand as well, but the problem is that is a very complex process and a very big calculation. So, probably by the time you’ve got your answer as to where the glass is going to form your volcanoes stopped erupting because you need such a big computer and you’ve got to leave it for so long.

Chris - But engineers can say “oh, don’t fly” when there’s a volcano, but pilots may not be able to avoid one if one suddenly goes off. So, under those circumstances, obviously they could try to avoid the ash cloud but there are potentially going to be particles going into the engine so what does that do, just shorten the lifetime of the engine?

Anna - Yeah. If it’s just a case of more straightforward sand which isn’t going to melt then the front part of the engine bears the brunt of that. If you’ve ever been on the beach on a windy day and the sand gets whipped up into your face and it stings, if you imagine doing that at 600 miles an hour that's what happens to the fan and the compressor, so the sand particles blast the blades.

We design the blades very carefully. The tolerance on them is around the width of a hair and then you’re blasting random bits off with sand, suddenly you don’t have nice, smooth shapes that you designed and the air won’t pass as smoothly through. So you start losing efficiency, you start using more fuel. If that’s a commercial plane that means you’ve got to pay more for your ticket, and you’ve probably got to start replacing bits.

Chris - Presumably, if you do end up with this sort of damage to the engine, this can be monitored and you could replace the blades that are worn?

Anna - Yes, yes you can. And one of the things that we do in our lab is we look at different forms of damage and see when is it bad enough that it needs to be replaced.

Chris - Yeah. So you basically know what the ‘safe’ threshold to operate on is?

Anna - Exactly.

Chris - Right then, better just stay on the ground in that case! That was Anna Young from Cambridge University.

Izzie - Jess Johnson is also here from University of East Anglia. What about other technologies? Can volcanic eruptions affect what’s going on at home as well?

Jess - They can, yes. People who live near volcanoes probably do have to deal with some of the issues associated with them on a day to day basis. Particularly if there is ash, it could be drawn into their electronic equipment. Your computer usually has a fan to cool in down in the same way that it could damage the jet engines, but not quite the same way. But the ash can clog up the computers, damage the computers, clog up air conditioning units and things like that.

Ash also acts in a very strange way when it gets wet. It gets quite heavy and almost cement-like and so if you have an accumulation of ash on your roof or on your gutters and then it gets wet then it can be very very heavy. There have been cases of people that have flat roofs, those roofs collapsing under the weight of the ash.

Izzie - My goodness. Obviously, if we have an eruption all of that gas and that ash can get redistributed over the globe so can that also then move onto other areas and perhaps impact people’s lives in other ways as well?

Jess - Yeah, absolutely. Depending on the size of the eruption the ash column can get into different layers of the atmosphere and be distributed. It can affect the climate and it can affect crops as well.

Chris - While we’re talking about gases and things, Jess, there have been reports in the past of volcanoes that are belching up gases which then, being heavier than air, flow down into valleys and settle in low points and asphyxiate people. Is that just apocryphal or does that happen?

Jess - That does happen, yeah. I think the famous example was in Cameroon where there was a bubble of CO2 that got released from a volcano that had a water lake inside it. And, yeah, because CO2 is one of the big gases that is released from volcanoes, and it is heavier than air, it does just settle in a valley and, yeah, people died because there wasn’t any air to breathe, there wasn’t any oxygen.

Chris - When you talked about mud just now I wondered if you were also going to talk about the manifestation that’s happened in Guatemala with mud flows?

Jess - Exactly.

Chris  Because one of the things that Izzie was talking about was the Iceland eruption and the fact that there was a lot of snow. And so you’ve got a lot of heat with a lot of snow which creates a lot of water so you get this toxic combination of mud formed because you’ve got ash with water and the whole thing turns into a big catastrophe?

Jess - Yeah. We call the “Lahars” and they’re a very common phenomenon. What happens is it can happen during the eruption if there is an eruption during a heavy rain or a monsoon. You can have water and the ash mixed together and cause a very fast flowing mud flow which can be very damaging. It can happen during the eruption, or it can happen at a later date if the ash has accumulated on the volcano and then there is an addition of water. So, ice melting or a rainy season or something like that, the ash can be remobilised, can cause big landslides and mudflows. And, as I said before, this stuff is like cement so it can be really really damaging.

Izzie - Absolutely. Now what about some of the gases that get into the atmosphere? We heard about global cooling and what are some of the problems with the gases that are released as well? Because we heard about asphyxiation, but can they poison crops and things like that?

Jess - They can, yeah. Sulphur dioxide, one of the main gases that’s released from a lot of volcanoes, when it mixes with water it causes sulphuric acid, and that can cause acid rain that can erode metal and can also poison crops and livestock. People who live downwind of Kallawaya, for example, will be very familiar with what they call “vog,” it’s volcanic fog made up of sulphur dioxide.