Dr Grace Nield

Post Doctoral Research Associate

What do you do?

I am a Geoscientist and computer modeller specialising in the large-scale deformation of the Earth in response to changes in loading at the Earth’s surface, such as the melting of the Antarctic Ice Sheet.

I have been a researcher in Antarctic Science for almost ten years but have never set foot on the icy continent, preferring instead the comfort and warmth of my office.

How are you involved in this area of science? 

My research involves modelling solid Earth deformation in response to changes in the weight of the Antarctic Ice Sheet. As Antarctica loses ice, the weight on the Earth decreases and the surface of the Earth rebounds because the underlying mantle is readjusting to the new weight distribution.

Satellites are continuously measuring changes in gravity around the world, which is directly related to all mass change on the surface and within the Earth. This is one of the main ways we measure how much ice is melting in Antarctica – by measuring the mass change.

However, before we can estimate the mass loss just from ice, we need to correct the mass change from the underlying Earth’s readjustment; this is what my computer models output. We need to get this right to be able to accurately quantify current ice loss from Antarctica, and therefore its contribution to sea-level rise.

What do you love about this topic?

Computer modelling of the Earth is like solving a puzzle. There are lots of different pieces, but they don’t fit together in just one way. For example, we need to know how the Antarctic Ice Sheet has changed through time, the composition of the Earth’s interior, and how much the Earth’s surface is moving.

Putting these pieces together to make a picture then requires careful consideration. Does the picture look right? Would another piece with a different Earth composition fit better? Are there extra pieces like system feedbacks that weren’t considered before? This makes the work incredibly challenging but rewarding.

How does this work deliver real-world impact?

The work that I do forms part of assessments of current ice loss rates, and therefore contribution to sea-level rise from Antarctica. These estimates are then published in reports such as those from the Intergovernmental Panel on Climate Change (IPCC). Policy makers around the world can then use this information to plan for adaptations to sea-level change.