Earth Sciences in Conversation: Conall Mac Niocaill

Our Earth Sciences in Conversation series explores the lives and careers of members of the Department, showing readers the people behind our world-leading research. For this issue we sat down with Conall Mac Niocaill, Head of Department and Professor of Earth Sciences, to hear about the extraordinary twists that shaped his career, deep Earth mysteries still puzzling researchers, and why coprolite remains the undisputed king of outreach…

Interview by Charlie Rex

What or who inspired you to go into Earth Sciences?

I went to university in Galway to do a general science degree. Because I’d never come across geology at school, I had it in my head that I was going to do chemistry. I only started geology in my second year because I needed a third subject. Then we went on a field course to Connemara – the weather was absolutely abysmal. We were cold, wet and freezing, but I had this epiphany sitting on a hillside where I realised that if I stayed doing chemistry, everywhere I worked would probably look more or less the same, because labs are labs, wherever you go in the world. But if I continued down the geology route, everywhere I worked would look completely different. And, to be honest, I was never any good at drawing hexagons, so that more or less ruled out organic chemistry [laughs].

What was your favourite thing about growing up in Ireland?

I was actually born in Dublin, but we moved to Galway very early in my life, and I spent the first nine years living absolutely out in the sticks. I had an incredible amount of freedom. I could go out, run across fields, explore wherever I wanted, do stupid things and come home with cuts and bruises. That freedom to explore was probably the thing I appreciated most. I suspect children today don’t often get that same level of independence.

So you went to university in Galway. What happened after that?

In my third year at university, I became aware of the Erasmus scheme. At the time, geology students in Galway could either go to Brest in Brittany or Oviedo in Spain, and because I’d done French at school I decided to go to France. Brest itself wasn’t the prettiest place because it had basically been destroyed during the Second World War, but it was home to Ifremer, the French marine research institute. I spent the year there taking classes taught in French, which was quite an experience. I remember coming out of my first geochemistry lecture and telling my French classmates that I hadn’t understood a thing, and they just laughed and said they hadn’t either. Through the Ifremer connection we got to do all sorts of marine geophysics and seismic interpretation that we simply wouldn’t have had access to in Galway. After that, I went back to Ireland, finished my exams, and was offered a job with a large multinational energy company, who wanted to sponsor me through a Master’s in petroleum geoscience. Then I bumped into one of the professors on the stairs, who said there might be an opportunity to work with the Norwegian Geological Survey while registering part-time for a PhD. At the time, the energy sector was quite turbulent and jobs didn’t necessarily feel secure, whereas a PhD was something more useful in the long term. So in autumn 1991, I moved to Norway and started working in the geophysics group there. I did all sorts of things alongside the PhD, including airborne geophysical surveys and radiometric mapping.

Conall during his undergraduate days

And after Norway came America?

America was a bit of an accident, really. During my PhD I’d become interested in palaeomagnetic measurements, and there was a lab in Oxford run by Jim Briden and Elizabeth McClelland. I met them at a conference and they suggested I come over to Oxford occasionally to do measurements, which I did for a couple of weeks every January, partly because it got me out of the freezing Norwegian winters [laughs]. Towards the end of my PhD, we decided to apply for funding for a postdoc, but there was a bureaucratic disaster and the proposal missed the EU deadline. Then, out of the blue, I got an email from Rob Van der Voo in Michigan, who’d seen me give a presentation at a conference in Grenoble. He said he had some money left on a grant and asked if I wanted to come work with him. One of my colleagues in Norway looked at me and said, “You’d be an idiot to turn that down”. I submitted my thesis on the Friday and by Monday morning I was in Michigan starting my postdoc. Meanwhile, Oxford eventually got its act together and the EU fellowship was approved, so in 1996 I moved over here and have basically been here ever since. I became a departmental lecturer in 1998, gradually got more involved in teaching through Exeter College, and eventually the role evolved into an Associate Professorship and Tutorial Fellowship.

Was there a particular moment where you decided you wanted to pursue academia as a career?

It just happened gradually. There was never some grand master plan. I basically kept doing the next thing that looked interesting. I enjoyed one thing, then another opportunity appeared and I thought, “Well, that also looks interesting,” and I kept following those paths. I’m honestly the worst person in the world to ask for career advice because I’ve had extraordinary luck throughout my career. People backed me very early on, pushed me towards opportunities, suggested Erasmus, suggested Norway, connected me with opportunities in America. There’s definitely an element of survivor bias there too.

Etendeka, Namibia

Have there been particular mentors or role models who really shaped your path?

I’ve been very lucky with mentors throughout my career. I had a really good chemistry teacher at school who first pushed me down the science route, and then all of my professors in Galway were hugely influential. There were only five faculty members covering the entire geology course, and what they managed to achieve with very limited resources was extraordinary. One person in particular, Dave Harper, who was a palaeontologist, was a big inspiration because he managed to maintain a genuinely international research profile while carrying a huge teaching load in a tiny Department.  Andrew Brock got me into Geophysics while Paul Ryan encouraged me to consider a PhD and set up a project with the Norwegian Geological Survey.  In Norway, I worked with Mark Smethurst, who supervised me there and encouraged me to try all sorts of different things, and then there was this wonderfully mad palaeomagnetist called Trond Torsvik whose lab I used, and he  encouraged me to think on a big scale. But more generally, the biggest inspiration has simply been being surrounded by really bright people with interesting ideas. That’s particularly true in Oxford. You’re constantly surrounded by people doing fascinating things, and that energy is infectious.

What are the big questions that drive your research?

To some extent, my research has evolved in the same way as my career; by following interesting things when they appeared in front of me. A lot of my earlier work in the 1990s was fairly classic palaeomagnetism: reconstructing where continents were, how terranes moved around, and how tectonic systems evolved. But then I also became interested in the field behaviour itself, trying to understand what the geomagnetic field was actually doing through time. In the 2000s I worked quite a lot with Gideon Henderson on geomagnetic reversals and excursions. Then later I pivoted into applications in volcanology, using magnetic methods to look at emplacement temperatures and eruption rates in things like the Deccan Traps and the Etendeka flood basalts in Namibia. More recently, I’ve been doing very detailed magnetic stratigraphy work in Iceland with Adrian Muxworthy at Imperial. Ultimately, all of that work feeds into a much bigger question: what does geomagnetic field behaviour tell us about what’s happening deep inside the Earth? Seismology gives you a snapshot of the present-day Earth, but geomagnetism gives you a window into what was happening ten thousand, ten million, or even a billion years ago.

Conall Drilling in Iceland, 2016

What’s one big question in your research that remains unsolved?

One of the really big unsolved questions is when the Earth’s magnetic field started and how it was powered. Related to that is understanding when the solid inner core began to grow. We know the Earth has this layered structure, with a solid inner core surrounded by the liquid outer core, but we don’t know exactly when that solid inner core first formed. The latest estimates suggest it may have begun surprisingly late in Earth’s history, somewhere around the late Precambrian. That timing is fascinating because it overlaps with major changes in atmospheric oxygen levels and the rise of multicellular life. So you suddenly end up with all these interconnected questions. Did the development of the magnetic field help stabilise the atmosphere by protecting it from the solar wind? Did changes deep inside the Earth influence oxygenation? And was there then some relationship between oxygenation and the rise of complex life? Those are enormous questions, and we’re still a long way from fully answering them.

What’s the most exciting or unusual sample you’ve ever worked on?

As an undergraduate, one of my professors, Paul Mohr, had previously worked with the Smithsonian Institute in Washington and had access to lunar thin sections from the Apollo programme. I still remember looking at those moon rocks under the microscope. They were the most pristine rocks I’ve ever seen. On Earth, water gets everywhere, so rocks are always altered in some way. But these lunar samples were perfect. The plagioclase and pyroxene were just unbelievably pure. That probably remains the coolest thing I’ve ever handled. Although, interestingly, children tend to disagree with geologists about what counts as cool. I once did an outreach session in a primary school and brought along a schist from Everest, a basalt from the bottom of the ocean, and a meteorite. The children were mildly interested in all of them. Then I pulled out a coprolite and said, “this is dinosaur poo,” and suddenly that was the greatest thing anyone had ever seen. The dinosaur poo absolutely stole the show.

Conall in Greenland, 2004

You’ve done a huge amount of fieldwork. Do you have a favourite fieldwork memory?

Probably northeast Greenland in 2004. It was one of the most extraordinary places I’ve ever worked. Getting there involved multiple flights, tiny propeller planes, and finally a helicopter ride into complete isolation. We were there in mid-summer, so there was 24-hour daylight, and we were probably 500 miles from anyone else on the planet. The combination of absolute isolation, incredible scenery, and astonishing geology was just magical. There were no phones, no emails, almost no contact with the outside world. You could just spend day after day immersed in these incredible rocks.

If you could study any period in Earth history firsthand, which would you choose?

It would have to be the late Precambrian, although technically I’d need a spacesuit because there wouldn’t be enough oxygen for me to survive. But it would be a fascinating period to witness because so many major transitions were happening simultaneously. You’ve got changes in atmospheric oxygen, changes in the geomagnetic field, the possible growth of the inner core, and the rise of multicellular life. It’s just an incredibly interesting moment in Earth history.

You’ve had a long and very successful career. What are you most proud of?

That’s actually a difficult question because hopefully the thing I’m proudest of still lies ahead. But if I had to define success, I think it would be being able to say that I made a positive difference to the people around me. If I’ve helped students in some way, supported colleagues, or left the places I’ve worked in a better condition than when I found them, then I’d regard that as a success.

Conall in Dorset, 2000

How have you seen Earth Sciences change over the years as a field?

Massively. It’s become much more quantitative, much more predictive, and much more connected to societal challenges. We live on a planet with finite resources and a growing population, and Earth Sciences now sits right at the centre of questions around water, energy, food security, natural hazards, and climate change. At the same time, we still need curiosity-driven science because that’s often where transformative discoveries come from. Silicon chips and lithium batteries both emerged from people simply trying to understand fundamental science. Universities need to support both things: curiosity-driven research and work aimed at solving major societal problems.

You’re a huge proponent of outreach. Why is that important to you?

For me, it comes back to making a difference to people’s life trajectories. I was lucky because going to university felt accessible to me, but for many people Oxford still feels remote and unattainable. Yet those are often the people for whom studying somewhere like Oxford can make the biggest difference. Historically, a lot of people came here because it was simply expected of them. I think Outreach matters because it opens up access to this intellectual environment to a much broader group of people who can then go on and do extraordinary things elsewhere.

What advice would you give to any budding Earth Scientists?

Be curious. Be open to things that don’t initially seem like your area. Don’t box yourself into a discipline because the Earth doesn’t recognise our disciplinary boundaries. Geochemists, geophysicists, palaeontologists, volcanologists, they’re all ultimately trying to answer interconnected questions about the same planet. If something interests you, follow it, even if it means learning something completely new.

Drilling in Svalbard, 2008

What’s kept you in Oxford for so long?

Partly inertia, if I’m honest! But also, one of the best pieces of advice I ever got came from Keith O’Nions, who said that if you’re going to move somewhere, it should be a genuine step forward from where you already are. And the truth is there are very few places in the world that are a step forward from Earth Sciences in Oxford. The Department has brilliant colleagues, brilliant students, great facilities, and it’s a nice place to live. So I stayed. I’m probably institutionalised at this point anyway [laughs].

Last year you were Junior Proctor. What was that experience like?

It was intense. You’re suddenly dropped into the very highest levels of university governance and have to learn an enormous amount very quickly. But that was also the most enjoyable part of it. You get this extraordinary window into how the university actually functions, from the very top all the way down to staff hardship committees supporting people who can’t afford to replace a broken fridge. One thing I took away from it was a much greater appreciation for the people working in the central university and in professional services roles. It’s easy for academics to think of “the centre” as some faceless bureaucracy, but actually there are a lot of really good people trying very hard to make things work inside an incredibly complicated institution. Universities simply wouldn’t function without them.

What are the best parts and biggest challenges of being Head of Department?

One of the best parts is that you suddenly get this much broader view of everything happening across the Department. You see all these fellowship applications, grant applications, and projects, and you realise just how much extraordinary work is going on. It’s genuinely inspiring. The challenges are mostly the unexpected things that suddenly appear and consume your time. Financial pressures are always there, but it’s often the unforeseen HR issue or governance problem that blindsides you. Ultimately, the challenge is making sure you do the right thing and leave the Department in a better place than when you found it.

The Dzereg Basin in Mongolia

What do you think makes a good leader?

I think leadership is really about creating an environment where everybody can do their best work. A Department is a team made up of academics, professional services staff, technicians, students, everyone. Not everybody is doing the same thing, but everybody’s work enables everyone else’s work. My role is basically to try and clear clutter out of the way so people can get on with what they do best. At interview, I described the role of Head of Department as being there to absorb the nonsense cascading down from above and the frustrations bubbling up from below so that everyone else can continue functioning, and I stand by that.

Finally, what’s your favourite piece of fiction that involves Earth Sciences?

There’s a brilliant Danish thriller called Miss Smilla’s Feeling for Snow by Peter Høeg. It revolves around a meteorite in Greenland that contains rare metals, and there’s effectively a race to get hold of it. The story was apparently inspired by a meteorite displayed in the courtyard of the Natural History Museum in Copenhagen. It’s a fantastic book and was turned into a film as well. Definitely worth reading.