The #Batagay or #Batagaika crater in Siberia often referred to as the "Doorway to the Underworld" or the
"Gateway to Hell" is a
#permafrost #megaslump in Yakutia, Russia.

Dimensions vary by source, but the site covers around 192 acres (78 hectares)
and stretches two thirds of a mile (one kilometer) in length.

Logged of trees in the 1960s, its walls reach a depth of around 180 feet (55 meters)
and expose 650,000 years of geologic history.

Since first spotted in the 1960s by surveillance satellites, the crater has grownfrom an insignificant gully to a massive depression at an accelerating rate.

According to Sarah Cadieux, Sr. Lecturer and Associate Director of Environmental Science of Rensselaer Polytechnic Institute,
the crater area increased by almost three times from 1991 to 2018.

The Batagaika crater isn’t a crater at all,
it’s a #retrogressive #thaw #slump, a type of terrain called #thermokarst that occurs in areas underlain by permafrost.

No longer cooled by forest cover, the slump has become a self-sustaining #feedback #loop,
a portion of the ecosystem which has tipped into a new state.

This is not an isolated case, but rather a rapidly growing problem in the Arctic as
💥it warms three to four times the rate of the rest of the planet since 1979.

Called Arctic or polar #amplification, this phenomenon is a well established fact measured by instruments,
confirmed in climate computer models,
and reinforced by paleoclimate records.

Powerful anecdotal evidence occurred in the scorching heatwave of 2020 that saw the Russian town of Verkhoyansk
which lies north of the Arctic Circle hit a stunning 38° C (100.4° F) on June 20.

2020 also saw overall temperatures in the Siberian basin rise to nearly 11° F above normal,
shocking scientists and releasing #ancient #methane
not from ancient organic material,
but from #limestone.

Elevated methane in wetlands was expected, but not from #outgassing #rock.

A year later in 2021 Europe’s climate change service Copernicus Sentinel satellites recorded 118° F (48° C) in the Sakha Republic of Arctic Siberia,
and records continue to fall with temperatures over 100° F in 2023 as reported by CNN.

@gdeihl

https://geoffreydeihl.substack.com/p/permafrost-maybe-not

Permafrost? Maybe Not.

Has the Arctic tipped?

Sane Thoughts for Insane Times
Trends in Satellite Earth Observation for Permafrost Related Analyses—A Review

Climate change and associated Arctic amplification cause a degradation of permafrost which in turn has major implications for the environment. The potential turnover of frozen ground from a carbon sink to a carbon source, eroding coastlines, landslides, amplified surface deformation and endangerment of human infrastructure are some of the consequences connected with thawing permafrost. Satellite remote sensing is hereby a powerful tool to identify and monitor these features and processes on a spatially explicit, cheap, operational, long-term basis and up to circum-Arctic scale. By filtering after a selection of relevant keywords, a total of 325 articles from 30 international journals published during the last two decades were analyzed based on study location, spatio-temporal resolution of applied remote sensing data, platform, sensor combination and studied environmental focus for a comprehensive overview of past achievements, current efforts, together with future challenges and opportunities. The temporal development of publication frequency, utilized platforms/sensors and the addressed environmental topic is thereby highlighted. The total number of publications more than doubled since 2015. Distinct geographical study hot spots were revealed, while at the same time large portions of the continuous permafrost zone are still only sparsely covered by satellite remote sensing investigations. Moreover, studies related to Arctic greenhouse gas emissions in the context of permafrost degradation appear heavily underrepresented. New tools (e.g., Google Earth Engine (GEE)), methodologies (e.g., deep learning or data fusion etc.) and satellite data (e.g., the Methane Remote Sensing LiDAR Mission (Merlin) and the Sentinel-fleet) will thereby enable future studies to further investigate the distribution of permafrost, its thermal state and its implications on the environment such as thermokarst features and greenhouse gas emission rates on increasingly larger spatial and temporal scales.

MDPI

The risk of releasing ancient #carbon from thawing permafrost is at the heart of this afternoon session at #AGU23.

Part of "#Climate Change Impacts on Ground #Ice, #Thermokarst Processes, Geocryohydrology, and Ecosystem Dynamics of #Permafrost Regions I"

🔗🗓️ https://bit.ly/3Np5gff

#SciComm #EnvironmentalScience

Climate Change Impacts on Ground Ice, Thermokarst Processes, Geocryohydrology, and Ecosystem Dynamics of Permafrost Regions I Oral

This session solicits research on the impacts of climate change on ground ice and thermokarst dynamics, cryohydrogeology, and biogeochemical processes related to permafrost thaw. Ground ice stability is critical for permafrost dynamics as it controls thaw settlement and, therefore, thermokarst processes. As ground ice melts, new subsurface hydrological flow paths are formed, and thermokarst processes are triggered during and after phase change and land subsidence, altering the interactions between cryo-hydrogeological and biogeochemical processes from the site scale to the regional scale. These processes not only affect the geotechnical properties of infrastructure and plays a central role in periglacial landscape evolution but also dramatically modulate permafrost ecosystem carbon cycling. Monitoring and modeling the permafrost-thaw-induced thermokarst process and associated impacts on cryo-hydro-biogeochemistry and ecosystem carbon cycling are urgently needed for refining our understanding of the permafrost carbon-climate feedback. This session will address recent advances in the characterization of thermokarst, cryohydrological, and biogeochemical processes, in the understanding of the interactions between them, and in the various approaches available (e.g., in-situ, remote-sensing, process-based modeling, and machine learning approaches) to tackle related scientific questions. Specifically, we welcome studies that map, measure, characterize, and model permafrost ground ice stability, thermokarst dynamics, and their associated impacts on cryohydrological processes and permafrost carbon cycling across spatial scales.

AGU - AGU23
Tracking lake drainage events and drained lake basin vegetation dynamics across the Arctic - Nature Communications

The Arctic is dotted with lakes, including thermokarst lakes highly threatened by climate change. Here, the authors investigate 35 years of lake drainage events and related vegetation trends across the Arctic, finding differences between thermokarst and non-thermokarst lake drainage events.

Nature

https://www.counterpunch.org/2023/10/27/20000-toxic-sites-in-sagging-arctic-permafrost/

Exposed yedoma permafrost along an eroded #Arctic coast. Image courtesy of the #NationalParkService.

#Yedoma is an organic-rich (about 2% carbon by mass) #Pleistocene-age #permafrost with ice content of 50–90% by volume.
"The deposits formed due to a combination of aeolian, colluvial, nival, and alluvial deposition and simultaneous ground ice accumulation. [...] #thermokarst

https://www.sciencedirect.com/science/article/pii/S0012825217300508?via%3Dihub

#ClimateChange #GlobalBoiling #permafrost #toxicsites

New #research: Can we trace development stages and ecology of a #permafrost thaw lake throughout the Holocene? Using an innovative combination of sedimentary proxies (ancient #DNA, #diatoms, #XRF), @Iza_bai et al. show: Yes, we can!

Long-term evolution of Central #Yakutia's vital #alaas #thermokarst lakes is traced throughout past millennia. This may help understand future pathways of culturally important lake systems!

#sakha #siberia #alas #newresearch #aDNA #eDNA

https://doi.org/10.1007/s10933-023-00285-w

Permafrost-thaw lake development in Central Yakutia: sedimentary ancient DNA and element analyses from a Holocene sediment record - Journal of Paleolimnology

In Central Yakutia (Siberia) livelihoods of local communities depend on alaas (thermokarst depression) landscapes and the lakes within. Development and dynamics of these alaas lakes are closely connected to climate change, permafrost thawing, catchment conditions, and land use. To reconstruct lake development throughout the Holocene we analyze sedimentary ancient DNA (sedaDNA) and biogeochemistry from a sediment core from Lake Satagay, spanning the last c. 10,800 calibrated years before present (cal yrs BP). SedaDNA of diatoms and macrophytes and microfossil diatom analysis reveal lake formation earlier than 10,700 cal yrs BP. The sedaDNA approach detected 42 amplicon sequence variants (ASVs) of diatom taxa, one ASV of Eustigmatophyceae (Nannochloropsis), and 12 ASVs of macrophytes. We relate diatom and macrophyte community changes to climate-driven shifts in water level and mineral and organic input, which result in variable water conductivity, in-lake productivity, and sediment deposition. We detect a higher lake level and water conductivity in the Early Holocene (c. 10,700–7000 cal yrs BP) compared to other periods, supported by the dominance of Stephanodiscus sp. and Stuckenia pectinata. Further climate warming towards the Mid-Holocene (7000–4700 cal yrs BP) led to a shallowing of Lake Satagay, an increase of the submerged macrophyte Ceratophyllum, and a decline of planktonic diatoms. In the Late Holocene (c. 4700 cal yrs BP–present) stable shallow water conditions are confirmed by small fragilarioid and staurosiroid diatoms dominating the lake. Lake Satagay has not yet reached the final stage of alaas development, but satellite imagery shows an intensification of anthropogenic land use, which in combination with future warming will likely result in a rapid desiccation of the lake.

SpringerLink
#Yedoma is an organic-rich (about 2% carbon by mass) Pleistocene-age #permafrost with ice content of 50–90% by volume.
"The deposits formed due to a combination of aeolian, colluvial, nival, and alluvial deposition and simultaneous ground ice accumulation. [...] The substantial amount of ground ice in Yedoma makes it highly vulnerable to disturbances such as #thermokarst and thermo-erosion processes." https://www.sciencedirect.com/science/article/pii/S0012825217300508?via%3Dihub #climateChange #Siberia #Yukon #Alaska #zombie #Pandoravirus

#FieldworkFriday

Some impressions from my first trip to #Alaska in 2015.
😀 🤩

Wildfires and thick smoke in the interior along the Dalton Highway.
#Thermokarst #lake dynamics (expansion + drainage) and #polygons on the North Slope.