Methane beneath Svalbard may be an underestimated climate risk

Hundreds of gas flares in the fjords

In 2021, UNIS master's student Nil Rodes and researcher Peter Betlem (now at NGI) chartered a small research vessel. Their goal was to conduct the first natural gas surveys in Isfjorden since 2015. Expectations were low, as the published scientific literature indicated that very few gas seeps had been documented in that area. However, data from a 2015 research cruise led by MARUM (The Center for Marine Environmental Sciences at the University of Bremen) suggested otherwise. With simple instruments and measurements funded by the Research Council of Norway's Arctic Field Grant, Betlem, Rodes, and their team confirmed that the fjord was indeed full of gas seeps.

“We found hundreds of flares across the entire fjord. The geological system beneath Svalbard is far more active than we previously thought,” says Betlem.

The findings not only challenged the existing literature but also raised a series of fundamental questions that had not been previously addressed. Betlem describes it like this:

“We saw hundreds of flares, but we had no idea what was driving them. How deep was the gas coming from? How much was escaping? Was there temporal variation? And why did some flares pulse and disappear within hours?”

A system in constant change

The research team also lacked answers to whether the variations were linked to temperature, pressure changes, potential gas hydrate dissociation, or specific structures in the bedrock. These knowledge gaps necessitated further investigation, and the proof-of-concept study led to a joint MARUM-UNIS research cruise in September 2023. This time, on board Germany’s Heincke research vessel – the same vessel as in 2015 - to systematically survey Svalbard’s western fjords for the identification of further seepage evidence. Building on the data from all three surveys, Rodes recently initiated a PhD project that investigates the extent of seepage and the reasons behind the dramatic variation in methane emissions.

“We know that there is a lot of gas, and we know that it escapes into the fjords. But we still don’t know what actually controls the variability across the fjord,” says Rodes.

The fjords reveal what we cannot observe on land

Rodes' PhD is part of an international collaboration, including NGI, UNIS, MARUM, UiT - The Arctic University of Norway, and the University of Barcelona. The goal is to understand what the fluctuations in the fjords can tell us about the processes unfolding beneath the permafrost on land.

“The geology is the same, and the petroleum system is the same. Having said that, it is challenging to measure gas escape directly on land,” Rodes explains.

In the fjords, however, the researchers can literally observe the bubbles escaping from the fjordbed. This active seepage allows testing hypotheses about pressure, temperature, gas hydrates, and faults and fractures that may act as pathways for gas migration.

“The fjords act as a natural laboratory. They help us understand conditions beneath the permafrost without drilling or excavating into the tundra,” says Betlem.

How much does this matter for the climate?

Methane has 25 times more greenhouse gas effect than CO2. In deep fjords, some of the methane dissolves and reacts with oxygen in the water, breaking down, and thus little of it reaches the atmosphere, if at all. However, in shallower areas, such as those closer to shore, the opposite occurs: methane may escape directly into the air because it doesn't have time to dissolve in the water column.

Today, researchers estimate that methane emissions from groundwater springs formed after glacial retreat (so-called glacial forefields) already correspond to around ten percent of Norway’s annual emissions from the energy sector (Kleber et al., 2023).

“We know that methane exists beneath the permafrost on land; numerous boreholes have confirmed it. The big question is how a weakening permafrost barrier will affect potential leakage pathways”, says Betlem.

A research challenge that cannot wait

This is not about the entire permafrost system collapsing at once. Even in a rapidly warming Arctic, the thickest permafrost layers in the mountains are expected to remain intact for centuries (Peng et al., 2023). The real risk lies elsewhere: in the localized weaknesses that can form long before the main body melts.

“In Svalbard’s valleys, the permafrost is relatively thin and young, locally only a few thousand years old (Gilbert et al., 2018), and therefore much more vulnerable to warming and degradation,” says Betlem.

Here, minor breaches (so-called taliks) in the permafrost can form over the course of years or decades, faster even in front of retreating glaciers. Such early openings may create new pathways for methane to rise to the surface and, in the worst case, trigger reinforcing local processes (Hodson et al., 2025; Kleber et al., 2023).

“Once cryosphere degradation begins to break up the permafrost lid, the process can reinforce itself and set off a chain reaction. This is what we are trying to understand before it happens,” he explains.

For Rodes, the PhD project is ultimately about giving both scientists and society a stronger foundation for decision-making.

“When we understand the fjords better, we can also understand what might happen on land, and what we risk in a rapidly warming Arctic,” Rodes concludes.

References:

Birchall, T., Jochmann, M., Betlem, P., Senger, K., Hodson, A., & Olaussen, S. (2023). Permafrost trapped natural gas in Svalbard, Norway. Frontiers in Earth Science, 11. https://doi.org/10.3389/feart.2023.1277027

Gilbert, G. L., O’Neill, H. B., Nemec, W., Thiel, C., Christiansen, H. H., & Buylaert, J.-P. (2018). Late Quaternary sedimentation and permafrost development in a Svalbard fjord-valley, Norwegian high Arctic. Sedimentology, 65(7), 2531–2558. https://doi.org/10.1111/sed.12476

Hodson, A., Kleber, G., Platt, S., Kalenitchenko, D., Hensgens, G., Fynn, T., Senger, K., Tveit, A., Øvreås, L., Ten Hietbrink, S., Hollander, J., Ammerlaan, F., Damm, E., Römer, M., Fransson, A., Chierici, M., Delpech, L.-M., Pirk, N., Sen, A., & Redeker, K. (2025). Methane in Svalbard (SvalGaSess). SESS Report 2024. https://doi.org/10.5281/zenodo.14425572

Kleber, G. E., Hodson, A. J., Magerl, L., Mannerfelt, E. S., Bradbury, H. J., Zhu, Y., Trimmer, M., & Turchyn, A. V. (2023). Groundwater springs formed during glacial retreat are a large source of methane in the high Arctic. Nature Geoscience, 16(7), 597–604. https://doi.org/10.1038/s41561-023-01210-6

Peng, X., Zhang, T., Frauenfeld, O. W., Mu, C., Wang, K., Wu, X., Guo, D., Luo, J., Hjort, J., Aalto, J., Karjalainen, O., & Luoto, M. (2023). Active Layer Thickness and Permafrost Area Projections for the 21st Century. Earth’s Future, 11(8), e2023EF003573. https://doi.org/10.1029/2023EF003573

Rodes, N., Betlem, P., Senger, K., Römer, M., Hodson, A., Liira, M., Birchall, T., Roy, S., Noormets, R., Smyrak-Sikora, A., Olaussen, S., & Bohrmann, G. (2023). Active gas seepage in western Spitsbergen fjords, Svalbard archipelago: Spatial extent and geological controls. Frontiers in Earth Science, 11. https://doi.org/10.3389/feart.2023.1173477