Oxford Sparks

[MUSIC]

Emily Elias: Volcanoes aren’t just above ground. There’s a whole world of volcanic activity under the sea. But observing them can obviously be tricky for researchers who have this like tiny habit of needing to breathe. So why not get a robot involved? On this episode of The Oxford Sparks, Big Questions Podcast, we are asking how can robots investigate underwater volcanoes?

[MUSIC]

Emily: Hello, I’m Emily Elias, and this is a show where we seek out the brightest minds at the University of Oxford, and we ask them the big questions. And for this one, we found a researcher who got in a boat and went for a cruise around Santorini, all in the name of science.

Sofia Della Sala: I’m Sofia Della Sala, I’m a researcher in the Department of Earth Sciences at the University of Oxford, and I like to call myself a volcanologist, but I guess technically I’m a volcanologist in training. I like to study all things volcanoes and their environments.

Emily: Okay, so you recently came back from a research trip to Santorini. Can you just sort of set the scene for me? What is volcanic activity like in Santorini?

Sofia: So Santorini, and most people will probably know it as like a luxury tourist destination. It’s like, oh, I’m going to go sit on the beach, drink a cocktail, watch the sunset. But actually, it’s an active volcano. So when you’re jetting off on your holidays, you are very much in a volcanic zone. It’s not super active right now in the sense of we’ve not had an eruption since the 1950s, but we have had two kind of like seismic crises, I guess you could call them like seismic events. One was in 2011, 2012, and then one has just, or as I guess fading out now, just happened in February 2025.

So it’s definitely got activity, even if the lava is not spewing out as people typically think of activity around volcanoes. So it’s quite a well-studied system in terms of in the geology world, even though I feel like in kind of wider society, people are not always super aware that it’s a volcano. And it’s kind of been studied well, but also not well, but I don’t know how to describe it. It’s been then historically people have gone back to it multiple times to try and tease out new information.

But there’s been I think a bit of a disconnect in the kind of wider geosciences, everyone’s kind of gone and done something specific, but there’s not necessarily been much interconnection where that’s kind of I think started recently, and it’s super exciting to see how the volcanic system is connected to the hydrothermal system, to the tectonic system, which is where the kind of earthquakes originate from and all of that. So it’s patchwork, sort of like research bits that haven’t quite been like linked together into like one big narrative.

Emily: You can go back to February because you were supposed to go on this trip before all of this sort of activity started kicking off again. And there was a state of emergency that was declared in Santorini right before you’re supposed to go, how did that affect your trip?

Sofia: Yeah, it was quite a whirlwind before heading off. And a lot of details weren’t sorted until some like the week before really. It meant that there was a lot of uncertainty, but it also offered us an opportunity to really understand the system better. So I’m so grateful that the expedition did go ahead, even though I was meant to go on the land before the expedition, the expedition was a cruise. So it took all place on a boat, but I was meant to actually go to the island itself. And that I decided not to do that portion because we were still feeling magnitude five earthquakes. And a lot of the population, a lot of the people who lived in Santorini had left the island. So I felt like if the people know best, you know the people who lived there, they are the experts.

Emily: Local on this one, not a great time to go hang out.

Sofia: Yeah. So I decided to just go straight to the boat. So it did affect that side of things, but thankfully the data and the science was not affected. So we still managed to go to land to do what we needed to do whilst on the cruise. So all we have all the data. And actually the fact that this cruise was in March, not in February. So it was kind of on the tail end of the seismic crisis, meant that we had such a unique opportunity to gain data that really you can’t otherwise get, you know, these expeditions are years in the making. You can’t just charter a boat and head off to try and get some data. So it was offered us an opportunity to gain data that we have never been able to collect before, which will hopefully be able to allow us to be better informed in the future. It’s kind of one of those like lightning striking sort of opportunities where yes, it’s a crisis, but once in a lifetime opportunity to gain this data that you desperately want.

Emily: Can you just like walk me through what you were doing on the cruise? What kind of data were you after?

Sofia: So we were specifically focused on the hydrothermal system. And this is when sea water gets sucked under the Earth’s crust essentially and heated up by magma before then coming back to the surface as hot springs. So some people might have been fortunate enough to go swimming in some lovely hot springs around the world. That’s essentially hydrothermal activity. And that’s what we were focusing on because it’s the kind of lesser studied aspect of this system. And we were hoping it would be able to give us some insights into the volcanic activity and also into potential kind of tectonic earthquake activity as well relating all of these different moving parts.

So in order to do that, we were a really interdisciplinary team led by Isabelle Yao from the National Oceanography Centre. We had geophysicists, geochemists, sedimentologists, volcanologists, honestly any kind of geoscientists under the sun was on that boat and it really meant that we could tackle the question from all angles. So we had a lot of seismic instruments that we deployed and would be silly not to considering the seismic crisis. But what I was specifically mostly involved in was in the work with the remotely operated vehicle, which is essentially a robot that we send down to the seafloor, and it has cameras. So it’s like our eyes on the seafloor and we can go exploring, which is really, really cool. And we, with that robot, collected samples, took measurements, essentially anything that we can’t do because we can’t spend hours at the seafloor as humans. So we kind of use technology to help us do that.

Emily: What does this robot look like, describe it for me?

Sofia: I think it looks quite cute, other than maybe it’s red and yellow. It’s like a big box, it’s kind of cube shaped and it has these two mechanical arms on either side that the pilot will control to pick up things or to pick up instruments. And then it has tray at the bottom, kind of at the same height as the arms because the arms need to grab things from the tray. And in that tray you can kind of, it’s a customisable robot, build your own. You can add any sort of thing that you want.

So we sometimes on our dives had fluid samplers in the tray because we wanted to collect fluids from the hydrothermal vents. Other times we had what we call push cores, which are essentially these plastic tubes that we can then push down into the seafloor to collect material that we call sediment. Or sometimes we have gas samplers to collect any gases coming from the hydrothermal vents. Or we have a temperature probe to measure the temperature of the sediments or fluids or anything else. So it’s really customisable to your own aims that you have.

And we did 22 dives in total, which is, that’s a lot of dives.

Emily: Incredible.

Sofia: Some of them were lasting like 12 hours. So it was like lots of hours working with this robot. And so it really means that every dive was also quite unique. You could customise it to your needs, also based on the location in which you were diving. So that was pretty cool.

Emily: And I mean like that robot, you’re not just like walking into a shop and buying a robot that can go underwater. That thing has got to take some serious years to develop.

Sofia: Absolutely. It also comes with its whole own team. There’s the ROV, a really operated vehicle team with pilots and engineers. Like as a scientist, we do not touch the robot. Like I do not go near that thing. I do not operate it. I do not drive it. We are just like the little voices in their ears saying go left. I think I see a hydrothermal vent. And it’s the pilots and the engineers who really carry that whole operation. So they’re absolutely invaluable. And the robot itself goes through so much maintenance and care at the National Oceanography Centre. And we were so lucky to be able to bring it on board. And it’s so much painstaking planning and organisation. And yeah, let’s not forget money. This has to be funded and we’re so, Isabelle was so incredibly good at being able to secure that funding so that we could carry out this expedition. But the ROV team are fantastic. And they’re also poor them. Sometimes we made them traverse the Caldera for six hours and saw nothing and saw for them as well. And sometimes we would say, look, there’s bacteria. They come exciting. It’s bacteria. And they’d be like, okay, yeah, bacteria. They go on other cruises where they see octopuses and go and see the incredible deep sea. And we were excited by some flocks of bacteria because it meant that we were maybe near a hydrothermal spring. Yeah, different vibes for different people, you know?

Emily: Well, exactly. Some people are all about the multicoloured fish and stuff.

Sofia: Me. I like some mud.

Emily: It sounds like you have a lot of data to analyse. What are some of the questions that you are looking for in it?

Sofia: So related to the activity, a question that my team more rightly is looking at is whether there we can see any geochemical changes before the seismic activity and after the seismic activity. And do we see any differences in the gas compositions coming out of these vents or the fluids? And that sort of thing. So that was one kind of aim that slightly changed given the seismic crisis. That was not necessarily something that we had anticipated needing to look at. But obviously, an opportunity calls and we will take it. And then more broadly, understanding just the geochemistry of the system in general. It’s never that any data has not been published on this system, like the fluids from the vents or even like a lot of the gases and stuff like that. So just understanding what the chemistry is telling us because then we can compare it to other systems worldwide and see what makes the system unique. Or maybe it’s very similar chemically to other systems and that will make us understand it more as well because then we have more data from other systems and how they have acted in the past to be able to inform how this one may act.

Emily: So would you want to go back and do something like this again where you’re on a boat losing your mind for hours and hours and hours, sending out a little robot, was this like, I don’t want to say it. Fun?

Sofia: Well, it’s a very particular type of fun. I will admit that. I am, but no, of course. It’s being able to see something that is kind of unseeable, you know, like who can get to see the sea floor like hundreds of metres below the surface. Like it’s very few people in the world can say that they have been able to do that. And I think there’s something extremely special in that privilege and there’s also something like a connection. I’ve been reading about the system, Santorini, its hydrothermal system, its volcanic eruptions and studying samples from there for two years. But to actually see it with my own eyes has brought a whole new dimension to my project and to my connectedness with my research and giving me like a real surge of motivation to get to the bottom of it all and find the nitty-gritty details.

So even just at that aspect, I think at any future projects I do, being able to really get up close and personal with the subject matter is at least for me personally, quite an important aspect of the research and that might not be for everyone. But definitely I would, I would not say no to another cruise, although now that I know what it’s like, I can be a little bit more prepared, you know, you’re on a boat not touching land for a month, the vegetables run out, it’s like, it’s a whole kind of vulgar, yeah.

Emily: I had a colleague once tell me going on a work trip, however much underwear you think you need to pack, double it.

Sofia: Oh my gosh, 100% agree, I thought I brought like excess underwear and I was doing so many washes, I was like every, like I was like why am I constantly in the laundry room, I don’t understand.

Emily: This podcast was brought to you by Oxford Sparks from the University of Oxford with music by John Lyons and a special thanks to Sofia Della Sala.

Tell us what you think about this podcast, we are on the internet at Oxford Sparks where you can go to our website, OxfordSparks.ox.ac.uk.

I’m Emily Elias, bye for now.

[Music]