Researchers have identified the physical and chemical processes that drive the intrusion of salt into permafrost in the Arctic. The findings were reported by the press service of Skoltech through Geosciences and Energy and Fuels, highlighting a shift in how permafrost behaves under changing climate conditions.
Across the Arctic Ocean, large reserves of methane hydrates or clathrate deposits are known to exist. These compounds consist of methane molecules trapped within a lattice of water ice, a stable form that endures under the region’s low temperatures and high pressures, including those at the seabed. Global warming is destabilizing these hydrates, and the presence of salt further lowers the melting point of the ice. When hydrates thaw, substantial quantities of methane can be released, accelerating atmospheric warming and feeding a feedback loop that worsens climate change.
In a controlled program, Skoltech researchers examined multiple marine permafrost samples and observed that the introduction of salt speeds up the breakdown of methane-bearing deposits. Further experiments and modeling revealed that the decay rate depends strongly on the hydrostatic pressure exerted by ocean water on the frozen ground, with higher pressure altering the pathways through which salt ions penetrate and interact with the hydrates.
The team also explored how different salts and ions influence permafrost stability. Their results showed that ordinary table salt and magnesium chloride have a more pronounced effect on degrading methane hydrates than sodium sulfate or potassium sulfate, which exhibit a relatively gentler influence on dissolution rates. These distinctions help explain why some coastal regions might experience quicker permafrost thaw than others under similar warming scenarios.
Using the experimental data, researchers quantified how salt penetration changes permafrost temperatures. They found that specific ions such as sodium, magnesium, and chlorine create localized zones where phase transitions occur at both high and low temperatures. This understanding could enable better prediction of thaw patterns and support strategies aimed at mitigating and managing the consequences of permafrost loss in Arctic environments (Source: Skoltech press release).
In related climate considerations, experts note that Greenland’s ongoing ice sheet reduction contributes to rising sea levels. Projections indicate that continued melting could elevate global sea levels by significant margins, emphasizing the interconnectedness of Arctic thaw dynamics with broader oceanic and coastal impacts (Source: Skoltech press release).