Estimating permafrost distribution using co-located temperature and electrical resistivity measurements

Abstract

Assessing the lateral and vertical extent of permafrost is critical to understanding the fate of Arctic ecosystems under climate change. Yet, direct measurements of permafrost distribution and temperature are often limited to a small number of borehole locations. Here, we assess the use of co-located shallow temperature and electrical resistivity tomography (ERT) measurements to estimate at high-resolution the distribution of permafrost in three watersheds underlain by discontinuous permafrost. Synthetic modeling shows that co-located temperature and ERT measurements allow for supervised classification schemes that provide 60% higher accuracy compared to unsupervised methods. Linking resistivity and size of the identified permafrost bodies to surface observations, we show that tall vegetation (>0.5 m) and gentle slopes (<15°) are related to warmer and smaller permafrost bodies, and a more frequent occurrence of taliks.