Meet the Team

How did you become a Deep Earth Explorer?

As a child in the Netherlands, I thought being a seismologist might be boring as I thought you would mostly sit around waiting for earthquakes to happen... I went to do a degree in geology as I liked sciences, but wanted to do something applied and observational. The course required many weeks of camping each year, which was a big plus. In my second year I learnt that Earthquakes are happing all the time and got introduced to all the interesting things that could be observed with earthquake waves – this inspired me to start doing research in seismology!

What are you working on right now?

In my research I am looking at the source of the volcanism that created the Galapagos Islands 3000 km down inside the Earth! I also supervise a number of research students, teach courses, communicate our science, and write research proposals to do new scientific projects in the future.

What's the favourite thing about what you do?

The Earth only gives us limited clues as to what is stored and happening inside it. Sometimes it feels like the Earth has set up a treasure hunt for us! I like that my work feels like piecing together the different parts to the puzzle, and I get to do so with a great team.

Best fact about our planet?

The inner core is growing out of the outer core adding millions of kilograms of solid iron a second, which sounds shocking, but this only amounts to about a millimetre of growth in size each year.

How did you become a Deep Earth Explorer?

Since I first came across these concepts in high school, I’ve always been fascinated by different geoscientific phenomena, such as heat transport processes in the Earth’s atmosphere and oceans, hydrology, carbon transport and storage or the rock cycle. Studying geophysics at university, I discovered the field of geodynamics and first learned about the convective flow of rocky mantle material powered by heat from the underlying core and its implications for conditions at the Earth’s surface, which I found to be an incredibly intriguing topic that I wanted to continue exploring. I especially loved that trying to better understand mantle convection meant learning not only about geodynamics, but also different fields like mineralogy, geology and seismology.

What are you working on now?

Imaging major seismic discontinuities around 410 and 660 km depth that occur due to changes in the mineral phase assemblage and associated material properties in the mantle transition zone. These discontinuities, which play an important role in shaping mantle flow dynamics and consequently impact material and heat transport between the Earth’s core and surface, are themselves defined by temperature and composition of the mantle and can be mapped using reflected and converted seismic waves. By constraining lateral variations in discontinuity depth, we may be able to better understand the geological evolution and present-day structure of the Earth.

What is the favourite thing about what you do?

The fact that, even though we are not able to look into the deep Earth directly, we are continuously improving our understanding of fundamental processes in the interior of our planet by linking theoretical models with observations from different geoscientific fields of research.

Best fact about our planet?

A lot of processes taking place at or close to the surface of the Earth like plate tectonics, volcanism, rifting, mountain building, sea level variations, sedimentation and drainage patterns, to name but a few, can be linked to and are affected by the extremely slow movement of rocks beneath our feet over millions and millions of years.

How did you become a Deep Earth Explorer?

Becoming a palaeontologist had always been my dream career since I was probably about five years old, while fossil hunting on Yorkshire’s Jurassic coast. After starting an undergraduate degree in Geology at ICL though I quickly realised that I was sorely missing the lack of maths and physics in the degree, which is how I stumbled upon Geophysics!

What are you working on now?

I am currently investigating the short-scale topography along the base of the Mantle Transition Zone (MTZ) by analysing travel-time, slowness, and back azimuth deviations in high-frequency PKPPKP waves, which travel through the outer core and reflect along the MTZ. I like to tell people that I’m looking at mountain ranges deep within the Earth.

What is the favourite thing about what you do?

Simply the opportunity to explore the hidden depths of our planet, which is simultaneously so fundamental to everything we know whilst also remaining so mysterious to us. Seismology provides a unique window into Earth’s interior structure, and into the dynamics that are taking place many hundreds / thousands of kilometres beneath our feet.

Best fact about our planet?

The Earth's inner core is hotter than the surface of the sun! The extreme heat drives the dynamic processes that shape the Earth's interior, and even influence geological phenomena on the surface too.

How did you become a Deep Earth Explorer?

Learning about volcanoes for a presentation in primary school planted the seed of geology in my head. This blossomed at university where I took a course in geology in first year and loved it immediately! Later in the degree, a series of projects made me increasingly interested in seismology and what is going on deep beneath our feet.

What are you working on now?

Mapping as much of the core-mantle boundary as possible for the presence of, and crucially the lack of, ultra-low velocity zones using diffracted shear waves. This would tell us about the driving forces behind their locations, giving clues about their origins and composition.

What is the favourite thing about what you do?

Since geology, and especially geophysics, is so much newer and smaller than the classical sciences, each person makes a big impact!

Best fact about our planet?

How interconnected everything is: the ultra-low velocity zones I study may be linked with mantle plumes, which in the deep past have fed magma to country-sized volcanic areas, leading to mass extinctions that have influenced the course of animal evolution.

How did you become a Deep Earth Explorer
I’ve always been deeply fascinated by the processes operating deep within our planet. Our world is delicately balanced, and this is reflected in the interactions between the atmosphere, biosphere, hydrosphere, cryosphere and geosphere. Without plate tectonics, these systems simply wouldn’t be able to interact, and life couldn’t exist in the way we know it today. I’m therefore interested in understanding what happens deep inside our planet and how these processes ultimately drive plate tectonics.

What are you working on now?
I am currently investigating ultra-low velocity zones (ULVZs) at the Earth's core–mantle boundary using diffracted P-waves and their postcursors. Using these higher-frequency waveforms allows us to complement earlier studies that used diffracted S-waves, providing new insights into the morphology, location and velocity reductions of ULVZs. Moreover, diffracted P-waves offer an opportunity to investigate scattering in the lower mantle and improve our knowledge of deep Earth heterogeneities. Building a clearer picture of the deep Earth is key to understanding how ULVZs may influence surface volcanism, mantle circulation and the planet’s long-term evolution.

What is the favourite thing about what you do?
I study structures the size of Olympus Mons — nearly 3,000 km beneath our feet — all from my office in Cambridge! It’s incredibly exciting to work with seismic data collected by stations across the globe, reflecting the international collaboration that seismology demands. Humans have never drilled deeper than about 12 km, but seismology allows us to explore far beyond this — I get to “look” all the way down to our planet’s core!

Best fact about our planet?
The outer core might be “leaking” upwards! The extreme velocity reductions observed within many ULVZs (up to -30–50% in shear-wave velocity) are far too large to be explained by thermal effects alone, suggesting a strong compositional component. One possible explanation is enrichment in iron: some models propose that small droplets of liquid iron from the outer core diffuse upward into the lowermost mantle, creating iron-rich patches that could account for the seismic anomalies associated with ULVZs.