Generating a new approach to calculating earthquake hazard

“Growing up on the Jurassic Coast – halfway between Axminster and Lyme Regis –­ has meant I’ve always been interested in geology.”

To look at a landscape and read a story that has been happening over hundreds of thousands, or even millions, of years has intrigued Dr Zoë Mildon ever since she was a child looking at fossils on the beach at Lyme Regis. “Geology has really changed the way I see the world. I can't now look around and just see a hill – I look at it and I see a story and a history.”

Thanks to the passion of her schoolteachers – and enjoying watching Iain Stewart documentaries ­– Zoë’s interest in the hazard side of geology began to take shape. This motivated her to study Natural Sciences at the University of Cambridge and specialise in geology, following this up with a PhD looking at earthquakes and faults in central Italy at University College London. It was during this time at UCL that Zoë got a taste of teaching, demonstrating classes in the lab and the field. “Having that opportunity to teach made me realise how much I enjoyed it. I love when you're talking to a student about a concept and there's that moment where it just clicks with them.”

“My parents have become more interested in geology since I became a geologist. They often ask me to explain the rocks or a landscape when we’re out, or they send me photos from their holidays.” 

Zoë comes from a family of teachers and now shares similar circles with them as a lecturer in Earth Sciences at the University, a post she began in 2018. “Teaching is a way of communicating my passion and enthusiasm. I also really enjoy public engagement and outreach, because alongside teaching you are inspiring the next generation to take the science further and find solutions to some of the challenges we face.”

Earthquakes are Zoë’s main passion, particularly looking at and understanding how, where and why do they happen and the hazard they pose to local communities. Her research has taken her across the globe – from spending four months in Sendai in Japan, one of the areas hit by the 2011 Tōhoku earthquake, to Italy, Pakistan and China.

Closer to home, Zoë loves the outdoors and enjoys hiking on Dartmoor and surfing, but also likes to indulge in baking and a bit of swing dancing. “Plymouth is within a really beautiful part of the world and having lived in London the pace and the quality of life here is so much better than what I had before.” The University takes advantage of its location and the natural resources and environments we are blessed with.

“When I look at other universities and where they go on field trips so many come to the South West. We have so much good geology on our doorstep – the Jurassic Coast UNESCO World Heritage Site and the English Riviera UNESCO Geopark are only a short drive away.”

Zoë is a strong believer in being a role model for STEM subjects and showing that geology is not just looking at rocks. 

“I very rarely look at rocks for my research. Most of my work is done either outdoors in the field or by modelling on my computer.” 

Part of Zoë’s role is to be visible as a female scientist and to showcase what she does to inspire the next generation. “Girls tend to be put off science by the age of six or seven and it's seen as a boys subject still. Geology itself isn't really taught in schools very often. Students only get a little taste of it through learning about the rock cycle, dinosaurs, volcanoes and earthquakes.”

Since joining the University, Zoë has taken part each year in Girls into Geoscience created by colleagues Dr Sarah Boulton and Dr Jodie Fisher – an outreach initiative to provide crucial role models for aspiring female scientists across the Earth Science spectrum, as well as promoting diversity and equality in the field. “Girls into Geoscience is fantastic because it gives girls a taste of what there is in geology, but also allows girls to meet each other – a lot of them say they're the only girl in their geography or geology class.”

In addition to her teaching, Zoë was thrilled to recently become a UK Research and Innovation Future Leaders Fellow, which ensures she gets to spend at least the next four years focusing on an individual research project she calls Quake4D. A project worth £1.1 million, it unites geology, physics and computer modelling to develop new approaches to understanding and calculating earthquake hazard. This stands as Zoë’s proudest achievement to date.

The Future Leaders fellowship is different to most other funding streams because their ethos is very much about investing in the research, but also the researcher. It was a big moment for Zoë because the science behind it had gone through several different evolutions since an initial proposal in 2017. 

“It was a real high point. I’m pretty sure I cried when I got the email to say that I'd been successful, and had to get my husband to check that I had read the email correctly.”

Quake4D is about trying to understand earthquakes, not just in three spatial dimensions, but also in time – hence the four dimensions part of the name. The main aim of Zoë’s project is to address a current problem that there is within earthquake hazard research.

To currently work out what the hazard to an area might be geologists would typically look at a few different data sets, such as ‘what earthquakes have been recorded in the recent past?’, ‘where are the faults?’, ‘how big are they?’, ‘how fast are they moving?’ Crucially most of this information is typically quite incomplete because historical records have not been kept for very long anywhere in the world.

People routinely model faults and earthquakes in numerical simulations. However, typically they assume that faults are very simple – which is not what we actually see in nature. “When I go into the field I can see that these faults are not straight lines at the surface, they curve and they change in their direction.” What Zoë’s PhD research showed is that those curves and those bends and changes actually affect how those faults may generate earthquakes. “If you don't include the geological complexity you're going to potentially miss out on the science.”

What we do know is that there are places in the world where we get earthquakes that we are surprised by. The 2011 Tōhoku earthquake in Japan was much bigger than anybody thought it could be. The 2003 Bam earthquake in Iran happened on a fault that nobody knew existed. While the 2016 Kaikōura earthquake in New Zealand was one of the most complicated faults ever recorded. 

“We can't just sit around and wait for more earthquakes to see what else happens because, firstly, we'd be waiting a really, really long time and secondly, it would be a humanitarian crisis if we just did nothing.”

Geology as a science is challenging because data is often quite disparate and separate. For example, if a chemist needed to collect more data they could do more experiments. Or if a biologist needed more biological samples they could go and collect or grow more in a lab.

“With geology we can only observe what is there. This means geologists tend to be quite flexible and creative thinkers because you're having to deal with separate data sets to make up a story.”
This is where Quake4D fits in, combining very traditional geological observations with cutting-edge physics-based numerical simulations.

Zoë next to a fault line in the Maiella National Park in southern Abruzzo, Italy

Zoë next to a fault line in the Maiella National Park in southern Abruzzo, Italy

Zoë is going to build a computer-based earthquake simulator that will be able to take all the geological information that we use to understand earthquakes and make a physics-based simulation that essentially spontaneously generates earthquakes. Zoë can then use this data to look over longer time scales to search for patterns that we can't see in nature.

Italy will be the first focus of this research because it’s an area that Zoë is familiar with and has some of the best data sets on faults. 

“The idea is to work in the best area of the world to develop this approach and then take that to other areas in the world where there isn't as much data available. There's a lot of evidence to show that the best way of reducing earthquake damage is to prepare for earthquakes, by working out where big earthquakes can happen, making buildings earthquake-proof and educating local people and governments.”

Zoë acknowledges the contribution and support of her colleagues and collaborators and believes mentorship is really important within academia. Without them she doesn’t think she would have been able to steer Quake4D through its initial rejections. “Asking for advice and building a support network for yourself is what makes us resilient.”

Potentially running until 2028, the main goal of Zoë’s fellowship is to make sure the research will have real, tangible links to the people and organisations that are actually going to benefit from the research.

Putting data sets from a different country or a different region into the model and then for it to just stay on my computer won’t help anybody. I want to build links to take this model and talk to risk insurance companies, to civil protection organisations and even change government policy.


<p>2016 earthquake damage in Amatrice, Italy<br></p>
2016 earthquake damage in Amatrice, Italy
<p>Zoe visiting a site after the 2016 Kumamoto earthquake<br></p>
After the 2016 Kumamoto earthquake in Japan
<p>Zoe conducting fieldwork in central Italy<br></p>
Conducting fieldwork in central Italy

Photography credits: Dr Zoë Mildon and Dr Lucy Campbell