Massive "Doomsday Glacier" May Be More Stable Than Initially Feared - SciTechDaily

The study, published in Science, included simulating the demise of West Antarctica’s Thwaites Glacier, one of the world’s largest and most unstable glaciers.

The researchers combined the variables of ice failure and ice flow for the first time, finding that stretching and thinning of ice, as well as buttressing from trapped chunks of ice, may moderate the effects of fracture-induced marine ice cliff instability.

The new findings add nuance to a previous theory called marine ice cliff instability, which suggested that if the height of an ice cliff reaches a certain threshold, it can suddenly disintegrate under its own weight in a chain reaction of ice fractures.

The Thwaites Glacier in Antarctica—sometimes referred to as the “Doomsday Glacier”—is moving closer to this threshold and could contribute nearly 3 feet to sea level rise in the event of a complete collapse.

The research team also found that icebergs that crack and fall away from the main glacier in a process known as “iceberg calving” may actually stave off, rather than contribute to, catastrophic collapse.

Bassis notes that even if the glacier doesn’t catastrophically collapse, exposing a tall cliff could still trigger a retreat at a few kilometers per year—equal to the length of about 20 football fields— and resulting in a large contribution to future sea level rise.

While it’s clear that Thwaites and other glaciers are melting, the speed of their demise is of keen interest to coastal areas as they develop strategies to adapt and build resilience.

But predicting the retreat of glaciers is a mind-bendingly complex business, as they’re affected by the interplay of myriad factors—the stress and strain of billions of tons of shifting ice, changing air and water temperatures and the effects of flowing liquid water on ice, to name just a few.

“These important insights will inform future research into the retreat of Thwaites Glacier and other large outlet glaciers of the West Antarctic ice sheet that are vulnerable to retreat via ice cliff failure and marine ice cliff instability,” she saidJ

Bassis says the research team is already working to refine their models further by incorporating additional variables that affect glacial retreat, including how the shapes of individual glaciers affect their stability and the interaction between glacial ice and the liquid ocean around it.

Reference: “Transition to marine ice cliff instability controlled by ice thickness gradients and velocity” by J.

The study is part of the International Thwaites Glacier Collaboration.

The research was supported by the DOMINOS project, a component of the International Thwaites Glacier Collaboration, and by the National Science Foundation (grant number 1738896) and the Natural Environment Research Council (grant number NE/S006605/1).

A change in the understanding of how glaciers melt or what the contributions are to global warming do not change the fact of the melting and rate, the fact of global warming and rate.

June 17, 2021

June 17, 2021

June 17, 2021

June 17, 2021

June 17, 2021

June 17, 2021