Self-sustaining soil cavity hole

Observation by Leanne Bulger:

There is a small soil cavity (approx 3m depth, <1m width) in the UAF North Campus boreal forest, within the lower Skarland Trail system. It has a small opening in the organic layer (19cm wide) that stays open all winter on its own, and it is located on the sidewall of a thermokarst that resembles a dropout doline. It creates a protective snow "chimney" and has for the last 2 years. The cavity holds a stead temp of 0.5-2°C and emits a high concentration of CO2.

LEO Says:

Thank you Leanne for this really unique and interesting observation. We have seen many observations in LEO Network about permafrost thaw, thermokarsts, methane seeps and related phenomena, but nothing that quite meets your description. We have attached some observations and news stories about other subsurface phenomena to provide context. Also, we have shared your observation with some friends in the LEO Network who are active on permafrost related issues; at the UAF Permafrost Lab and through the Permafrost Discovery Gateway (see links). We look forward to learning more on the topic and following this story in the years ahead.

AI Comment from Gemini 2.5 Pro:

This observation of a persistent soil cavity with high CO2 emissions adds another facet to the impacts of changing permafrost conditions documented in LEO. Previous posts have frequently highlighted the formation of larger thaw features like thermokarst lakes (Alaska's newest lakes are belching methane) and massive sinkholes, sometimes formed dramatically (Yakutia has a MASSIVE hole in the ground... and it’s growing, Methane explodes under Yamal tundra, creates another sinkhole), or posing risks to infrastructure (Sink Hole in Road Impacting Home Foundation).> While many reports focus on methane (CH4) release from thawing permafrost, whether from lakes (Arctic lakes bubble from seeping methane gas), subsea reservoirs (A Massive Methane Reservoir Is Lurking Beneath the Sea , Russian scientists find 'most powerful' ever methane seep in Arctic Ocean), or even unexpected terrestrial locations like a Fairbanks golf course (For methane researcher, golf course bubbles are a first) and coastal vents (Natural Gas Vent), this observation is distinct due to the high concentration of CO2 and the specific physical structure—a small, stable cavity maintaining an opening through winter.> This highlights the varied ways subsurface changes manifest, emphasizing the value of local observations in capturing the full spectrum of permafrost thaw impacts, which are being monitored through efforts like new AI-assisted technology.