Interview: "Retreating ice sheets can impact subsurface fluid migration and destabilize gas hydrates"

In this interview, iC3 postdoc Peter-Lasse Giertzuch discusses his research on ice sheet dynamics and subsurface fluid processes, their impact on the carbon cycle, and his passion for outdoor activities like kayaking and skiing.

Can you briefly describe yourself and your research ?
My name is Peter-Lasse Giertzuch, I'm a postdoc at the iC3 Polar Research Hub. My research focuses on subsurface fluid processes in high-latitude continental margins like Greenland and Antarctica. Specifically, I study how the dynamics of ice sheets—such as their advancement and retreat—affect subsurface fluid migration. This includes groundwater movement, which can influence land and ocean ecosystems, and free gas and hydrates that may destabilize and release gases into the ocean. These processes have significant implications for the global carbon cycle and climate systems.

Credit: Peter-Lasse Giertzuch

Why is it important to study these processes?
It’s important because, while we have a rough idea of what’s happening, there are still many research gaps. For example, the retreat of ice sheets could alter subsurface fluid migration, impacting groundwater, ocean ecosystems, and carbon release. Groundwater release could affect the biosystem of the ocean, while destabilized gas hydrates could release free gas into the Arctic Ocean, influencing the total carbon budget. To better understand our past and model our future, we need to identify the feedback mechanisms involved. My research uses geophysical data to investigate these topics.

How are you conducting this research?
Most of my work involves analyzing geophysical data, like seismic data and borehole logs, which means I spend a lot of time processing data on the computer. For example, I work with seismic data collected using air guns and hydrophones. The data I’m currently analyzing comes from a three-kilometer-long streamer with hydrophones generating vast amounts of data. My job is to process and analyze this data to extract meaningful insights.

I’ve also participated in research expeditions and was part of a research cruise across the North Pole with the i2B project, which focused on paleoclimate reconstruction in the Arctic Ocean. I worked with the ship’s sub-bottom profiler to study subsurface structures. These experiences have been invaluable, and I hope to join future expeditions, such as a potential cruise to Antarctica.

Credit: Tim Kalvelage

What did you work on during your PhD?
I completed my PhD at the Federal Institute of Technology in Zurich, where I studied fluid migration using radar waves. My research was part of a geothermal energy research project in the Swiss Alps. I used radar waves to visualize fluid migration pathways in fracture networks, using saltwater as a tracer. Although the scale and type of waves differ, the concept of wave-matter interaction remains consistent across my work.

What are the biggest challenges you face in your research?
One of the challenges I face is my limited background in geosciences, as my earlier studies were more physics-focused. This makes interpretation tasks more demanding, but I rely on the expertise within iC3 to bridge these gaps. Collaboration is a key strength of iC3.

If you had an unlimited budget for your research, how would you allocate it?
Instead of financing a specific project, I would focus on restructuring the academic system to prioritize continuity and stability in research. Short-term projects and frequent transitions often lead to a loss of know-how and inefficiencies. The reasons for this short-term system are mostly a lack of funding and project-based budgets. More and more working hours need to be spent on acquiring project funding instead of advancing science, and a lot of knowledge and scientific potential is lost. I believe these inefficiencies often cost more money than the system saves. So, I’d use budget to transform current academic working structures, allowing scientists to spend more time advancing science, ultimately saving money long-term.

You have been a debate trainer and even won awards for debating—how have these skills contributed to your scientific career?

Debating has been a great help in my scientific career, especially in structuring logical arguments and presenting ideas effectively. As a trainer and active debater, I learned to build compelling arguments, set clear premises, and support them with evidence—skills that closely align with writing scientific papers. The ability to create coherent argumentation chains has been invaluable in research, from forming hypotheses to presenting findings. Beyond that, debating has enhanced my communication skills, allowing me to engage more effectively with both scientific and non-scientific audiences, making complex ideas accessible and persuasive. 

Could you describe an ideal day off?
I enjoy outdoor activities like kayaking, skiing, hiking, and working on or riding my motorbikes. I've always loved the sea and in Switzerland I fell in love with the mountains, too. In Tromsø, I have it all.

Credit: Peter-Lasse Giertzuch

Peter-Lasse Giertzuch is a postdoc working at the iC3 Polar Research Hub in Tromsø, the capital of the Arctic. To find out more about his work, please check out his list of publications, or contact him by email.

If you are interested in joining the friendly iC3 team as a postdoc, read this.