Research will boost knowledge of melting Antarctic glaciers and sea-level rise

LAWRENCE — Sea-level rise is likely to be among the harshest consequences of global climate change. Higher oceans would spell catastrophe for coastal habitats and hundreds of millions of people around the world.

But the rate and extent of sea-level rise are challenging for researchers to gauge. The science of measuring and predicting the behavior of glaciers and polar ice sheets — one driver of rising oceans — is complex.

“Over the past 15 years, glaciologists have done a much better job measuring the current contribution of ice sheets and glaciers to sea level rise,” said Leigh Stearns, assistant professor of geology at the University of Kansas. “However, there are large uncertainties when it comes to predicting how glaciers will behave in the future. We still have a lot to figure out in terms of how and why glaciers change in different climates.”

Now Stearns has won a prestigious Faculty Early Career Development award from the National Science Foundation to better understand the dynamics of glaciers in Antarctica and how they will contribute to sea-level rise in different climates. She is studying the glaciers using an interactive numerical flowline model.

“A numerical flowline model is a relatively simple mathematical model that is based on conservation laws,” said Stearns. “These models are based on physical process but allow us to explore what happens under different climate scenarios. For example, we can measure how glacier speed will change if air temperatures increases by specific amounts.”

Stearns said that glacier response to environmental conditions vary across the Antarctic Ice Sheet, and her research using a numerical flowline model should shed light upon the reasons for this.

“It will allow us to better understand how glaciers change over time,” she said. “In particular, we’re interested in understanding why some glaciers are very sensitive to climate changes and others don't seem to be.”

The KU researcher’s focus will encompass glaciers across the continent.

“We're interested in almost all Antarctic glaciers, because we want to know what dictates their unique behavior,” said Stearns. “In terms of sea level rise, glaciers that are currently moving the fastest and have the largest catchment basins are important ones to understand first.”

Following her training as a geologist, Stearns quickly became interested in glacier dynamics and ice sheet mass balance. To better study and understand Antarctic glacier dynamics, Stearns has trekked to the continent nearly 15 times in the past 15 years.

“Glaciology is a rapidly growing field and allows me to do interdisciplinary research on a societally-relevant topic,” she said.

The NSF grant will allow Stearns to educate a new cohort of researchers entering the study of ice-sheet dynamics. Her team will build a Dynamic Antarctic Model that will be an online version of the flowline model. According to the grant proposal, students will gain an increased “comprehension of glacier dynamics, numerical models and applied mathematics by allowing users to manipulate model parameters and rapidly observe the effects.”

“We want to give students the opportunity to use real data and models to explore how glaciers change,” said Stearns.