'Tiger stripes' underneath Antarctic glaciers slow the flow

Catherine Zandonella in News at Princeton: Narrow stripes of dirt and rock beneath massive Antarctic glaciers create friction zones that slow the flow of ice toward the sea, researchers at Princeton University and the British Antarctic Survey have found. Understanding how these high-friction regions form and subside could help researchers understand how the flow of these glaciers responds to a warming climate.

Just as no-slip strips on flooring prevent people from slipping on a wet floor, these ribs or "tiger stripes" — named in reference to Princeton's tiger mascot — provide friction that hinders the glaciers from slipping along the underlying bed of rock and sediment, the researchers report online in the journal Science.

Researchers at Princeton University and the British Antarctic Survey used mathematical modeling and data from satellites and ground-penetrating radar to infer the existence of stripes or ribs (in red) indicating areas of high friction between the glacier and the underlying bedrock. These high-friction ribs slow the movement of ice toward the sea. The image on the left is the Pine Island Glacier and the image on the right is the Thwaites Glacier, both in West Antarctica. (Image courtesy of Olga Sergienko, Program in Atmospheric and Oceanic Sciences)

The researchers discovered these tiger stripes, which occur in large, slippery regions under the glaciers, using mathematical modeling based on data from the National Snow and Ice Data Center and the British Antarctic Survey. The work was conducted by Olga Sergienko, an associate research scientist in Princeton's Program in Atmospheric and Oceanic Sciences, and Richard Hindmarsh, a scientist at the British Antarctic Survey.

...Studying the bottom of these glaciers is next to impossible due to the inability to see through the ice, which is over a mile-and-a-half thick. Instead, the researchers used satellite measurements of the ice velocity and ground-penetrating radar collected from airplane flyovers to detect bedrock and surface topography, as well as field observations. Using the data, Sergienko created a mathematical model that calculated what happens inside the glacier as it flows along the bedrock. The model predicted the formation of the tiger stripes or ribs, which Hindmarsh had theorized some years earlier...

Researchers at Princeton University and the British Antarctic Survey used mathematical modeling and data from satellites and ground-penetrating radar to infer the existence of stripes or ribs (in red) indicating areas of high friction between the glacier and the underlying bedrock. These high-friction ribs slow the movement of ice toward the sea. The image on the left is the Pine Island Glacier and the image on the right is the Thwaites Glacier, both in West Antarctica. (Image courtesy of Olga Sergienko, Program in Atmospheric and Oceanic Sciences)