MAY 02, 2017 2:33 PM PDT

Measuring ice flow in the Antarctic Peninsula

A new study recently published in Geophysical Research Letters aims to clarify a dispute about a previous study’s misrepresentation regarding the Waster Palmer Land in Antarctica. The previous study, from the University of Bristol, published that the land mass was losing ice drastically fast – a 45 cubic-kilometer per year increase. But this new study, coming from researchers at the UK Centre for Polar Observation and Modelling at the University of Leeds, report that the number is actually three times smaller.

Photo: Phys

Lead author Dr. Anna Hogg, from the Leeds School of Earth and Environment, said: "Dramatic changes have been reported in this part of Antarctica, so we took a closer look at how its glaciers have evolved using 25 years of satellite measurements dating back to the early 1990s."

The earlier study used measurements of glacier thinning and mass loss from satellite measurements in order to come up with the number that the Leeds case has now denounced by saying that the degree of glacier speedup is far too small. In order to look more closely, the scientists from Leeds analyzed ice velocity over 25 years using satellite imagery to track changes in the speed of more than 30 glaciers since 1992. What they published represents an analysis of changing glacier flow in Western Palmer Land and proves that the region is losing ice due to increased glacier flow.

The study explains their findings: “More than 30 unnamed outlet glaciers drain the 800 kilometer coastline of Western Palmer Land at speeds ranging from 0.5 to 2.5 m/d, interspersed with near-stagnant ice. Between 1992 and 2015, most of the outlet glaciers sped up by 0.2 to 0.3 m/d, leading to a 13% increase in ice flow and a 15 km3/year increase in ice discharge across the sector as a whole.” The scientists found that the greatest flow increase was seen in glaciers that were grounded at depths more than 300 meters below the ocean surface. Watch the video in order to see a digital image. 

So, the long story short is that while the region is losing significant ice, it’s not quite as significant as first thought. Study co-author Professor Andrew Shepherd, from Leeds' School of Earth and Environment, explained: "Although Western Palmer Land holds a lot of ice -- enough to raise global sea levels by 20 centimeters -- its glaciers can't be responsible for a major contribution to sea level rise, because their speed has barely changed over the past 25 years. It's possible that it has snowed less in this part of Antarctica in recent years -- that would also cause the glaciers to thin and lose mass, but it's a not a signal of dynamical imbalance." Dynamical imbalance is the term that refers to ice loss due to increased glacier flow

The team plans to continue to monitor ice loss and glacier flow using satellites, with the aim of keeping an eye on climate change progess. Pierre Potin, ESA's Manager of the Copernicus Sentinel-1 Mission which was used in the study, said: "We will continue to use Sentinel-1's all weather, day-night imaging capability to extend the long term climate data record from European satellites."

Sources: Geophysical Research Letters, Science Daily

About the Author
Bachelor's (BA/BS/Other)
Kathryn is a curious world-traveller interested in the intersection between nature, culture, history, and people. She has worked for environmental education non-profits and is a Spanish/English interpreter.
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