Siberian permafrost hole/blowout

[ArgonneForest]

PBS Nova re-airing the Siberian Blow Hole show again first week of April, wed here.

A very good video by PBS. Most concerning, they found a lake which probably leaks methane through a fault line crack - Easy Lake methane escapes probably through fault lines nearby and Alaska is very active in terms of seismicity. This undermines the notion that permafrost will be a gradual release. At least in the Alaska regions with high seismicity one may look for fault line methane seepage.

PBS: Arctic Sinkholes
https://earthclimate.tv/video/arctic-sinkholes/

It does no such thing to undermine the current thinking on the rate of permafrost emissions.

[morganism]

Siberia’s mysterious exploding craters may be caused by hot gas

Several enormous craters left by explosions have been spotted in Siberia over the past 15 years, and a new explanation links them to hot gas – and climate change

Deep, cylindrical craters in the permafrost of Siberia have puzzled researchers since they were discovered a decade ago. Researchers now propose that the distinctive structures are caused by a build-up of hot gas beneath the permafrost. Warming Arctic temperatures might then weaken the permafrost so much that the gas explodes through its surface.

“Climate change is likely the triggering factor, but it happens there because you have the thinning of the permafrost due to the gas,” says Helge Hellevang at the…

(paywalled)

https://www.newscientist.com/article/2412072-siberias-mysterious-exploding-craters-may-be-caused-by-hot-gas/

[vox_mundi]

A diagram, cropped from the study, explains the process by which the exploding craters could be formed. The natural gas building up over a layer of sediment is represented in purple.

https://www.businessinsider.com/mystery-siberia-exploding-craters-may-have-finally-been-solved-methane-2024-1?amp

[morganism]

Am wondering if the induced seismicity of a couple of those holes blowing may be shaking loose the cap layers on others. Would be pretty bad if a real quake liquefied the over burden.
 The underwater karst fields up by Denmark show large fields of blown holes, and they are under pressure from the water.

[morganism]

map from here   ...  https://www.researchgate.net/figure/Tectonic-map-of-the-Jurassic-structural-stage-of-the-West-Siberian-petroleum-province_fig1_328619604




https://www.researchgate.net/figure/Maps-showing-the-relocated-epicenter-of-the-1908-earthquake-in-the-Barents-and-Kara-sea_fig4_332965372

[vox_mundi]

Study Offers New Explanation for Siberia's Permafrost Craters
https://phys.org/news/2024-09-explanation-siberia-permafrost-craters.html



Mysterious craters that first appeared in the Siberian permafrost a decade ago were caused by climate change-driven pressure changes that explosively released methane frozen underground, a new study reports. The research offers a fresh take on the origins of the craters first sighted on Russia's Yamal Peninsula in 2014.

The new study finds that the region's unusual geology, coupled with climate warming, kickstarted a process that led to the release of methane gas from methane hydrates in the permafrost.

"There are very, very specific conditions that allow for this phenomenon to happen," said Ana Morgado, a chemical engineer at the University of Cambridge and one of the study's authors. "We're talking about a very niche geological space."

The research was published in Geophysical Research Letters.

... The Yamal Peninsula's thick, clayey permafrost acts as an osmotic barrier—and warming is changing it. This 180 to 300-meter (590 to 980-foot)-thick layer stays permanently frozen throughout the year. An "active layer" of topsoil above it thaws and re-freezes seasonally.

Interspersed throughout the tundra and sandwiched within the permafrost lie unusual, one-meter-thick layers of unfrozen, high-salinity water called crypogegs, kept liquid by a combination of pressure and salinity. Underneath the cryopegs sits a layer of crystallized methane-water solids, called methane hydrates, which are kept stable by high pressure and low temperature.

But warmer temperatures are destabilizing these layers. Climate change has caused the active layer to melt and expand downward until it reaches the cryopeg, releasing water that travels via osmotic pressure into the cryopeg, the researchers found.

But there isn't enough space in the cryopeg to hold the extra meltwater forced in by osmosis, so pressure builds. The increasing pressure creates cracks in the soil that travel upward from the cryopeg toward the surface. The pressure gradient then reverses: the cracked soil causes a sudden drop in pressure at depth. That pressure change damages the methane hydrates below the cryopeg, which causes a release of methane gas and a physical explosion.

The lead-up to the explosion can last for decades, the study found. That timeline aligns with increasing climate warming starting in the 1980s.

Ana M. O. Morgado et al, Osmosis Drives Explosions and Methane Release in Siberian Permafrost, Geophysical Research Letters (2024)
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL108987

[vox_mundi]

Experimental Setup Simulates Arctic Methane Explosions
https://phys.org/news/2024-10-experimental-setup-simulates-arctic-methane.html

Russian researchers have developed an experimental setup that will help simulate gas-dynamic processes and predict explosions in Arctic soils.

... Skotlech's new apparatus is designed to perform experiments on frozen rock samples and to simulate a wide range of natural conditions by varying the ambient temperature and gas pressure according to a specified pattern.

The unique sample holder helps to compact the soil during the experiment and to measure changes in its linear dimensions and therefore porosity. The facility is equipped with acoustic sensors to detect changes in the ratio of ice, unfrozen water, and other phase components.

In this way, it is possible not only to measure gas permeability, but also to begin to study the complex processes that occur in real soil.

... "We have been studying explosions in the Arctic for 10 years and know almost everything about them. The rapid growth of a mound is the key indicator of an impending eruption. Of the two mounds we studied this year one exploded on August 30. Its growth rate was unusually high, more than 50 centimeters per year. Mounds can be monitored from space. We are currently looking at potentially dangerous spots in the Bovanenkovskoye field in Yamal," Bogoyavlensky said.



Igor Shkradyuk, the coordinator of the industrial greening program of the Biodiversity Conservation Center, said that while individual explosive events cannot be predicted, the increase in their intensity can be.

There are 6 billion tons of methane underground, hundreds of times more than in the atmosphere. As the ice thaws, emissions occur much more often than a decade ago, and the trend will continue. There are about 2,000 seeps at the bottom of the Arctic Ocean, and many more on polar islands. Their explosions can be compared to the detonation of a 10-ton TNT bomb, Shkradyuk added.

Evgeny Chuvilin et al, Gas flow in frozen hydrate-bearing sediments exposed to compression and high-pressure gradients: Experimental modeling, Cold Regions Science and Technology (2024)
https://www.sciencedirect.com/science/article/abs/pii/S0165232X24001915

[vox_mundi]

Thousands of Exploded Craters Discovered On the Kara Seabed
https://www.thebarentsobserver.com/climate-crisis/thousands-of-exploded-craters-discovered-on-the-kara-seabed/420773



“For the first time, via comprehensive aerospace research on the Yamal Peninsula, we have discovered 4992 zones of gas blowouts (explosions) in the form of craters… at the bottom of 3551… lakes and 16 rivers. In addition, we have identified another 669 zones of explosive degassing in the coastal zones of the Kara Sea”, - a study by a group of Russian scientists from the Oil and Gas Research Institute of the Russian Academy of Sciences reports, - “Taking into account the Yugorsky Peninsula and Bely Island, we have detected 6022 explosive degassing zones… including 905 offshore….”. According to scientists, the Sabetta district on the Yamal Peninsula is among the most gas-explosive.

http://eng.arctica-ac.ru/article/688/

... Methane emissions from the Yamal Peninsula and Western Siberia could potentially contribute to the greenhouse effect, but the Zeppelin Station, which monitors global atmospheric gases, hasn't detected anything catastrophic yet.

https://www.npolar.no/en/zeppelin/

Another reason why the formation of craters is a potential danger is the damage that gas explosions could cause to oil and gas infrastructure. While there is only one underwater gas pipeline in the Russian Arctic, in the southernmost part of the Kara Sea, Russia has many gas and oil pipelines on land.



“Widespread gas blowouts in the north of Western Siberia with the formation of craters on land and offshore can lead to emergencies and even disasters at oil and gas industrial facilities and to fires in the tundra,” the study concludes.