Glacial History Modifies Permafrost Controls on the Distribution of Lakes and Ponds

Accelerated Arctic warming is thawing permafrost and changing the distribution of lakes. Understanding the evolution of Arctic-Boreal lakes is critical to predicting climate feedbacks and monitoring ecosystems; however, previous research has found diverging lake area responses to permafrost thaw. Here, we demonstrate that permafrost controls on lake distribution are substantially modified by glacial history and geologic substrate texture. We present the new Alaska Lake and Pond Occurrence Data set (ALPOD), which shows a positive association between lake area and permafrost extent in unglaciated regions with fine substrate, but a negative relationship in postglacial areas. These spatial patterns indicate that thaw-driven lake area declines are concentrated in unglaciated regions, which we corroborate by showing that most documented decadal-scale lake area decreases occurred in unglaciated study sites. Overall, these findings provide potential mechanisms to explain previous disagreements in lake area trends and help constrain predictions of surface water change under further warming.

Duke Scholars

Author Sarah Cooley Earth and Climate Sciences