Permafrost Early Deformation Signals before the Norilsk Oil Tank Collapse in Russia

Despite the profound roles of surface deformation monitoring techniques in observing permafrost surface stability, predetermining the approximate location and time of possibly occurring severe permafrost degradation before applying these techniques is extremely necessary, but has received little attention. Taking the oil tank collapse accident in the Norilsk region as a case, we explored this concern by analyzing the permafrost deformation mechanisms and determining early surface deformation signals. Regarding this case, we firstly applied the Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technique to obtain its permafrost surface deformation rate, then utilized a sine model to decompose its interannual deformation and seasonal deformation, and finally compared the relationship between the topographic slope and deformation rate. Based on experimental results, we reveal that when the annual average temperature continuously increases at a rate of 2 degrees C/year for 2 similar to 3 consecutive years, permafrost areas with relatively large topographic slopes (>15 degrees) are more prone to severe surface deformation during the summer thaw period. Therefore, this paper suggests that permafrost areas with large topographic slopes (>15 degrees) should be taken as the key surveillance areas, and that the appropriate monitoring time for employing surface deformation monitoring techniques should be the summer thawing period after a continuous increase in annual average temperature at a rate of 2 degrees C/year for 2 similar to 3 years.

Automated summary

It is necessary to determine the approximate location and time of severe permafrost degradation before applying surface deformation monitoring techniques. This study analyzed the permafrost deformation mechanisms and identified early surface deformation signals using the case of an oil tank collapse in the Norilsk region. The results indicate that permafrost areas with large topographic slopes (>15 degrees) are more likely to experience severe surface deformation during the summer thaw period when the annual average temperature increases continuously at a rate of 2 degrees C/year for 2 to 3 years.