Invited perspective: What lies beneath a changing Arctic?

As permafrost thaws in the Arctic, new subsurface pathways open for the transport of groundwater, energy, and solutes. We identify different ways that these subsurface changes are driving observed surface consequences, including the potential for increased contaminant transport, modification to water resources, and enhanced rates of infrastructure (e.g. buildings and roads) damage. Further, as permafrost thaws it allows groundwater to transport carbon, nutrients, and other dissolved constituents from terrestrial to aquatic environments via progressively deeper subsurface flow paths. Cryohydrogeology, the study of groundwater in cold regions, should be included in northern research initiatives to account for this hidden catalyst of environmental and societal change. the underpinnings of many of these water-related changes lie beneath the depths of these investigations. Thawing of ancient permafrost is opening new subsurface pathways for groundwater flow (Walvoord and Kurylyk, 2016), thereby altering fluxes and distribution of water, energy, and solutes that can be observed at the Earth's surface. Scientific advances in predicting future climate change require integration of subsurface processes within a broader understanding of change in the Arctic, herein broadly defined to include Arctic and subarctic regions. We argue that groundwater is a catalyst of change in Arctic regions, and we call for a more prominent inclusion of cryohydrogeology, the study of groundwater in cold regions, in transdisciplinary research initiatives.

Automated summary

As permafrost thaws in the Arctic, new subsurface pathways open for the transport of groundwater, energy, and solutes, leading to increased contaminant transport, modification to water resources, and infrastructure damage. Groundwater is a catalyst of change in Arctic regions and cryohydrogeology should be more prominently included in research initiatives to understand these environmental and societal changes.