Profile

I grew up in Cardiff, and studied in various places throughout the UK before returning to Wales to work as a lecturer at Aberystwyth University. I sort of stumbled across geology as it wasn’t a subject which was taught at my school, but I was always interested in science, the natural world, and spending time outdoors, so it was great discovering a subject which combined all three. One of the real perks of studying ancient ice ages is that their record is spread all over the world, which creates some amazing travel opportunities, and means I can study some of the world’s coldest climates in some of the hottest places on Earth today (e.g. Death Valley). Outside of work I love reading, hiking, cooking, and spending time on one of Aberystwyth’s many beaches.

Enjoying a beautiful sunset over Aberystwyth’s South Beach

My work looks at the sedimentary record of glaciers and ice sheets, that is the material which is picked up, moved, dumped and pushed or squeezed beneath, within and in front of ice masses. Geology trains you to read rocks like a book, and in this sedimentary record you can read stories of when the ice was most extensive, when and how it melted, how much water was flowing at the base of the ice, how many times the ice masses shrank and grew, and all of this can tell you a lot about cold climates of the past, as well as help us predict what will happen to our glaciers and ice sheets in the future.

Picture on the left shows me in front of a modern glacier in the Austrian Alps which is rapidly melting back, exposing beautifully grooved and scratched rocks. The photo on the right shows glacial grooves left behind by 300 million year old glaciers in South Africa. The present really is the key to the past!

I’m particularly interested in a time period known as the Cryogenian (around 700 million years ago!) where we have evidence of glacial debris on almost every modern continent today, suggesting this was an ice age which affected the whole world! This was almost certainly the biggest and coldest glaciation in Earth’s history, but scientists are still actively debating how much of the planet was frozen at the same time, for how long, and how on earth we grew and melted such large ice sheets. Many scientsists argue for a ‘Snowball Earth’ climate state, where the whole planet was frozen at the same time for tens of millions of years, but my work argues that what we see in the rock record tells a different story…

Recognise this from Chris’s Christmas Lecture? This large boulder was dropped into mud and sand by a Cryogenian glacier, roughly 700 million years ago. These ‘dropstones’ provide excellent geological evidence of past glaciations. Today you can see them just outside of Death Valley National Park, in the blazing sunshine!

Most of my work is field-based, which means I travel all over the world to see and study the rocks where they appear on Earth’s surface today, and I’ve been lucky to travel to Namibia, Australia and the western USA on the hunt for these Cryogenian glacial rocks. A typical field day involves a hike to the rocks, and then taking lots of pictures with a camera and/or drone. I make lots of sketches and descriptions of the rocks, including very detailed drawings to scale called graphic sedimentary logs, and sometimes collect samples to look at thin slices of the rocks under a microscope when I get home. This can be extremely useful as some features are too small to see with the naked eye, and gives us extra information to support our field observations. My studies of these Cryogenian rocks show alternating periods where ice was growing and melting back, multiple times over the course of this glaciation, with lots of evidence of free-flowing meltwater, open ice-free oceans, and warm-based glaciers and ice sheets (like those in the Alps or Greenland today). So maybe more of a Slushball Earth, though I must admit that name doesn’t sound quite as exciting. Let me know if you have any better suggestions!

It can be useful to collect samples in the field to look at rocks in more detail. This picture shows Cryogenian glacial rocks from Namibia, where the small stones and pebbles have been stretched and squeezed as the ice rode over the top of the sediments. Look at all the beautiful colours of the minerals when you look at rocks under the microscope!

One of the great things about working at a university is no two days are the same, so it’s difficult to describe a typical day in some ways. Sometimes I’m teaching students in a big lecture theatre, sometimes it’s a hands-on practical in the lab, sometimes it’s out in the field either close to the uni or away on residential field trips. A big part of my job is scientific research, so I’ll spend time collecting data, writing up our results into academic papers, reading other people’s papers to learn about the latest discoveries, or attending conferences where scientists share these ideas in person (some of them with >15,000 scientists all in one place!). There are usually lots of meetings too, with students who are conducting their own research or want some help with their studies, with my colleagues to plan various activities in the department, and with my research collaborators who are spread all over the UK and beyond.

I work in the Department of Geography and Earth Sciences at Aberystwyth University. We’re lucky to enjoy a pretty incredible view from my office and many of our teaching rooms, and some truly unbeatable sunsets too.

Outside of term time I will often try to fit in at least one field trip to collect some new research material, and the days here are very different again. I often work in desert and semi-arid environments, where temperatures can get pretty high, so the days tend to start fairly early in the morning, and sometimes involve taking some time off in the shade mid-day until the temperatures drop again. These days are much more physically active, usually involving a 5+km hike to the rocks, the whole day exploring mountain ridges or creek beds looking for the best and most interesting rock exposures, and relaxed evenings by the camp fire or refuelling for the next day. Usually this type of fieldwork takes you far off the beaten track, and you get to see places and meet people you would probably never come across as a tourist, so getting to know the local area is a big part of these trips too, and we usually try to squeeze in some geotourism when we can e.g. Grand Canyon or Arches National Park.

A typical field day for me involves lots of hiking and scrambling over rocks, often in beautiful settings. This picture was taken near Death Valley, California. I’m stood on Cryogenian glacial rocks, and modern sand dunes can be seen in the background. People drive dune buggies all over these dunes so it wasn’t always the most peaceful setting!