One of the remarkable examples of volcano eruptions has to be Pompeii - the Roman City that was destroyed by the eruption of volcanic mount Vesuvius about 2000 years ago. Pompeii is particularly interesting because the volcanic ash ended up preserving the remains of the city and many of its inhabitants, providing a rich resource for scientists and archeologists today. And recently, the preserved remains of 2 more people have been unearthed in Pompeii archeological park. Katie Haylor spoke to archeologist Emma Pomeroy and volcano expert Jess Johnson...
Emma - So what they found are the remains of two individuals, as you said, they're two men, one seems to be older, perhaps between 30 and 40, and the other one younger. So in his late teens or early twenties. Now what they've actually found is, if you'd like, the void left behind by these men's bodies, when they were covered in ash. And then the bodies rotted away, the bones are still there. And so what they do when they find these voids, is pour in the material to take a cast of that hollow. By doing that, they can then see the actual shape of those people's bodies.
Katie - And Jess, how does a volcanic eruption end up freezing a city in time like this?
Jess - Well, one of the most deadly hazards from a volcanic eruption is called a pyroclastic density current. This is kind of like a flow, like an avalanche, but it's made up of volcanic ash, and boulders, combined with deadly gases, all at thousands of degrees, and traveling at hundreds of kilometres an hour. Very large pyroclastic density currents can create tens of metres of ash deposits. And in Pompeii, Mount Vesuvius had a large eruption, creating these pyroclastic density currents. In this case, probably the temperature likely killed the residents of Pompeii instantly, but then they were very quickly buried in the ash, as was the entire city. And so that is what preserved them.
Katie - Emma, what information can actually be gleaned from findings like this about, well, about things like what life was like for people in this ancient city?
Emma - A great deal. I mean, what's exciting about these individuals is, like I said, you've got the skeleton within these casts that they've been able to produce as well. So not only can we see the skeletal remains, and analyse them to look at things like age at death, whether individuals were male or female, and aspects of their life. So were they healthy? Did they suffer arthritis? All these kinds of questions. But then because we've got sort of the casts of their bodies as well, we can look at other things like what were they wearing? And in this case, the older man was wearing a woolen cloak, it looks like. And we can perhaps look at things that we can't tell very easily from the skeleton, what people's build and physique was like. And then you've got all the other evidence that gets preserved. So there's really remarkable sort of, everyday objects that come from Pompeii, including things like wooden furniture, and the remains of food, still in the bowls on tables, in some cases. It's really a whole host of evidence that actually, usually we don't get preserved in the archaeological record.
Katie - Now, Jess and Emma, I want to put this to you because on our forum, Peter's been wondering about volcanic ash. He says, the excavation of Pompeii must remove enormous quantities of this ash. So what do you do with it? How do you dispose of it? He reckons it might have a purpose as a soil improver. Emma, you probably deal with moving dirt and things around as an archaeologist. What happens to the stuff?
Emma - That's such a good question. And I'm actually really intrigued to know now what happens with the material from Pompeii. So usually in an excavation, we're usually removing just normal soil and sediment. And typically, unless the things that we're excavating are going to be left exposed for displays, such as Santorini or Pompeii, we actually fill back in the hole that we've excavated, partly to make it safe in some cases, sometimes because there's going to be new building work that takes place over the top, or sometimes perhaps to protect the remains that we have found for future generations. So quite often we actually put the material back. It's also important to remember that many archaeological excavations are not on the kind of scale that we're seeing in Pompeii. You know, it's really an amazing project that's been going on for such a long time. So that's a brilliant question. And actually in the case of Pompeii, I don't know, and would love to know.