Researchers at Skoltech wanted to understand more about the effect of pressure and temperature on salt distribution in permafrost that contains hydrates and permafrost that doesn’t. Existing research does not model salt diffusion and transportation in permafrost thawing.
They simulated experiments reproducing the degrading permafrost in laboratory conditions by changing the temperature and pressure whilst observing changes to the salt – sodium chloride (NaCl). They varied the gas pressures between 0.1 to 4.0 MPa whilst keeping a constant negative temperature of around −6.0 °C.
They found that the gas pressure affects the sodium in frozen hydrate-bearing sand with salt transport increasing at lower pressures and pore hydrates losing stability in the simulated permafrost. This slows down the permafrost thawing effect. They also found that the pressure on hydrate-free sediment in the simulated permafrost wasn’t significant.
The Skoltech research team can use these results to create models of changes in salt transport and distribution whilst frozen hydrate-saturated sediment are affected by different gas pressures. This may help in their ability to predict permafrost thawing behaviour.
Chuvilin E, Ekimova V, Davletshina D, Krivokhat E, Shilenkov V, Bukhanov B, (2022), Pressure Influence on Salt Migration in Frozen Hydrate-Saturated Sediments: Experimental Modeling, Energy Fuels, American Chemical Society, available at https://doi.org/10.1021/acs.energyfuels.2c01282