Is Climate Change Making Siberian Soil Explode?

Explosive Craters and Hidden Methane: How Osmosis is Shaking up Siberian Permafrost

Most people think that geology is boring. They think of geology as staring at still rocks that do nothing but exist for hours at end. However, at home, we are fascinated by geology.

That’s because, well, we do have a background in paleontology. But most important, because we don’t see geology as a boring static science. On the opposite, we think of geology as one of the most dynamic and powerful sciences to study.

For example, our friend Carl has been studying how rivers form and disappear and how, given the right circumstances, this can completely change a landscape in as little as an afternoon. Has anyone seen the Old Faithful in Yellowstone National Park?

Let’s not talk about seismologists studying earthquakes. How can you not be mesmerized at the idea of a giant crack forming in a few minutes following an earthquake?! Miles over miles of changed landscape in the blink of an eye. Watch the video below if you don’t trust me!

And these phenomena occur all around us on a daily basis. For example, my father-in-law’s farm lost a quarter of a hectare overnight following a massive flood that changed the course of the river. The farm building itself was just a few meters away from the flood damage.

A few weeks ago, something happened underground on our street that created a crater of dirt and rocks. It felt as if the Earth had spilled something, and we haven’t found an answer yet. I wished I had taken a picture.

However, there’s something that people have been paying attention to for the last decade or so. Let’s go back to remote areas, shall we?

Siberia’s landscape holds more than frozen tundra; it conceals craters formed through explosive methane release, sparked by a surprising mechanism — osmosis. First noticed in 2014 on Russia’s Yamal Peninsula, these craters puzzled scientists, prompting a search for answers.

A new study published in Geophysical Research Letters suggests that climate change-driven pressure changes trigger these explosions beneath the permafrost, releasing methane gas. Yup, climate change is showing its ugly head again.

By exploring the interplay between geology and climate, researchers have shed light on an unusual process with serious implications for our warming world.

The Yamal Peninsula is an Arctic lowland region with a permafrost layer [ground that has been frozen for at least two years at a temperature of 0°C (32°F) or below] that stays frozen year-round. However, as the Arctic warms, the seasonal thawing of the active layer (the soil on top that melts and refreezes each year) penetrates deeper into the frozen ground.

This warming has been suspected to destabilize methane hydrates — a mix of water and methane frozen under high pressure — locked within the permafrost. But as Dr. Ana Morgado, one of the study’s authors, puts it, “there are very, very specific conditions that allow for this phenomenon to happen.”

It’s not just any warming; it’s a combination of heat, osmotic forces, and the unique nature of Siberian permafrost.

The research team started by exploring the mechanisms that could drive the observed explosions. They dismissed chemical reactions as the source, focusing instead on physical processes. Using a combination of field data, modeling, and laboratory experiments, they investigated how meltwater, salt concentration, and pressure dynamics within the permafrost interact.

They specifically honed in on the cryopegs — one-meter-thick layers of salty, unfrozen water — and the osmotic pressures that cause water to flow and build pressure within these cryopegs, eventually cracking the permafrost above.

The process behind these explosions starts with warming surface temperatures, which extend the seasonal thaw deeper into the permafrost. Normally, the permafrost is a mix of frozen soil, ice, and trapped gases. But within it lie cryopegs — highly saline, unfrozen water pockets.

Due to the difference in salt concentration between surface meltwater and cryopeg water, osmosis kicks in, drawing fresh water downward into the cryopeg. This osmotic action increases the pressure within the cryopeg.

Over time, the pressure inside the cryopeg increases to a point where the frozen soil begins to crack, and the cracks work their way up toward the surface. When these cracks finally reach the surface, the pressure within the cryopeg is rapidly relieved, destabilizing the methane hydrates that lie beneath. Methane gas is then released in a violent explosion, creating a crater. Tell me you aren’t mind-blown yet!

According to the study, this whole process can unfold over several decades, aligning with increased warming since the 1980s. Dr. Julyan Cartwright, a co-author of the paper, likened the build-up to “pumping up your bicycle tire until it blows up — that’s physics.”

And just like a tire, once the pressure reaches a critical point, the explosion is quick and forceful. See the diagram below for a more graphical explanation.

However, these explosions are more than geological curiosities. The release of methane gas is a climate concern. Methane is a potent greenhouse gas, and its release into the atmosphere accelerates warming, which then promotes further permafrost melt — creating a feedback loop.

As Dr. Cartwright notes, these craters aren’t formed by a single factor. Instead, they’re the result of a unique set of conditions involving the combination of heat, pressure, and the cryopeg’s saline environment.

The phenomenon, however, seems to be quite localized. “We’re talking about a very niche geological space,” Dr. Morgado points out, suggesting that the specific conditions necessary for these explosions aren’t widespread across all Arctic permafrost. Still, the implications for methane emissions and their contribution to climate change are significant, particularly in a region where methane hydrates are abundant.

While the findings emphasize the unique nature of these explosions, they also raise broader questions about the stability of permafrost and methane hydrates worldwide.

It might not be happening everywhere, but where it does, the amount of methane released is noteworthy. Dr. Morgado warns, “the amount of methane that’s being released could have quite a big impact on global warming.”

The study’s insights contribute to a better understanding of how Arctic warming interacts with regional geology to produce explosive methane release.

However, further research is needed to determine how often these events occur and their cumulative impact on methane emissions. For now, it’s clear that osmosis is more than just a process learned in school — it’s a driver of significant geological and environmental change in Siberia’s rapidly warming permafrost.

And yet another super-cool example of how fascinating and far from static Geology truly is!