Deep within Greenland’s ice sheet, radar images reveal strange plume-like structures distorting layers deposited over years.

Now, more than ten years have passed since then, their discoveriesscientists think they have figured out the cause of these structures, but it’s really troubling. Modeling shows that plumes match convection surprisingly well. That is, upward transport of swirling heat is more commonly associated with burning. stirring of lava beneath the earth’s crust.

“The discovery that heat convection can occur within an ice sheet is a little counter to our intuition and expectations. But ice is at least a million times softer than Earth’s mantle, so the physics work out.” says glaciologist Robert Roe. He holds a Ph.D. from the University of Bergen, Norway.

“It’s like an exciting freak of nature.”

Greenland’s ice sheet, which covers 80% of the island, is one of the largest reservoirs of frozen water on Earth and is predicted to have a major impact on sea level rise. melt into the sea. Understanding the physics inside an ice sheet is essential to predicting how it will change over time.

This is why scientists use ice-penetrating radar. Radio waves pass through the ice and are reflected differently when they encounter the inner layer (snow that fell a long time ago and was compressed by more snow on top of it). Each of these layers has its own characteristics. For example, they have slightly different acidity levels and different dust, ash, and chemical content.

in 2014 paperScientists have described the strange structures these radar images reveal deep in the ice of northern Greenland. These large upward buckling features were independent of the topography of the underlying bedrock. present a puzzle Researchers have I’ve been trying to resolve it ever since..

Initiatives so far Mechanisms have been suggested, such as glacier meltwater freezing on the underside of the ice sheet. Moving from slippery areasmay be responsible for the structure. However, there was one idea that remained untested. Heat convection may occur within the ice sheet.

To test this idea, Lo and his colleagues turned to computer modeling. They created a simplified digital slice of Greenland’s ice sheet and asked a simple question: If the ice base is warmed from below, could convection form structures that match what radar sees?

They modeled a 2.5-kilometer (1.6-mile) thick slab of ice using a geodynamic modeling package typically used to simulate convection within the Earth’s mantle. They tweaked variables such as snowfall rate, ice thickness, ice softness, and the speed at which the ice moved across the surface.

Under the right conditions, the model began to generate plume-like upwelling. This was a rising column of ice that folded in the layers above it, creating a shape very similar to that seen in radar images.

The model shows that plumes form only when the ice near the base is warmer and significantly softer than standard assumptions, suggesting that if convection is the cause, the actual ice at the base of the northern Greenland ice sheet may also be softer than previously thought.

On the other hand, the heat required to generate these convective upwellings in the model is match the heat constantly flowing from the earth, generated by Radioactive decay of elements in the Earth’s crust and decay due to residual heat from Earth’s formation as the Earth gradually cools over billions of years.

This effect is small, but over time it can accumulate under a giant slab of insulation enough to warm and soften the ice above it.

“We usually think of ice as a solid substance, so the discovery that parts of the Greenland ice sheet actually undergo heat convection and resemble a pot of pasta is both wild and fascinating.” climatologist Andreas Born says: PhD from the University of Bergen.

Related: The world’s deepest gas hydrate, teeming with life, discovered off the coast of Greenland

Now, that doesn’t mean the ice is slimy. It is still solid ice and only flows on timescales of thousands of years. Also, this is not always the case melts quickly. Further research into the effects of convection on ice physics and ice sheet evolution is needed to determine what this means for the future.

“Greenland and its nature are truly special. The ice sheet there is more than 1,000 years old and is the only ice sheet on Earth with a culture and a settled population on its margins.” the law says.

“The more we learn about the processes hidden inside the ice, the better prepared we will be for the changes that will occur on coastlines around the world.”

This study cryosphere.