In Antarctica ice, hunt for climate change clueshttps://indianexpress.com/article/technology/science/in-antarctica-ice-hunt-for-climate-change-clues-global-warming-south-pole-5006479/

In Antarctica ice, hunt for climate change clues

Scientists measure ice rise dynamics over 4 weeks, say it can throw light on how ice flows into ocean

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The researchers’ camp on Blåskimen Island in Antarctica. Photo provided by study authors. (Vikram Goel)

It is a piece of a larger puzzle that begins with an ice rise in East Antarctica. Vikram Goel, 28, says he is not answering any big questions yet but is hopeful that what he has researched will be a step towards a larger understanding of how ice sheets in the region will behave with change in climate.

Goel is a PhD scholar, one of two students on a Ministry of Earth Sciences scholarship, to study at the Norwegian Polar Institute in Tromso. He has now co-authored a study in The Cryosphere, “Glaciological settings and recent mass balance of Blåskimen Island in Dronning Maud Land, Antarctica” — the result of measurements and data collection over four weeks spent on the field.

Blåskimen Island is an isle-type ice rise, which has thickened, Goel says following the observations and GPS measurements. An ice rise is a clearly defined elevation in an otherwise flat ice sheet.

“It is like a small dome on the surface,” Goel tells The Indian Express. “There are several ice rises across Antarctica, and they play a very important role in understanding the dynamics of ice sheets. It can throw light on how ice flows into the ocean and the speed with which the ice moves around it. Ice rises are valuable since they store information about the past and they remain in one place,” Goel says.

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All the information collected during the project will help feed in data points to calibrate a model that can replicate past information and forecast some aspects of the future, Goel says. says. It also provides information such as an indication of the position of the ice sheet — whether it was behind or over the rise — besides how far out the ice sheet was in the past, and how the flow will evolve as temperatures rise.

“In this paper, we have shown proof that this particular ice rise is definitely thickening. We have also shown a strong contrast in the surface-mass balance,” Goel says.

The “net ice added to the surface every year”, he explains, can provide information on the snow is distributed over the ice rise. “This information points to a good site from which an ice core — a column of ice — can be recovered. This will hold information about the past and will give us some idea of how far back we can go,” Goel says.

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GPS measurements on the field. Photo provided by study authors. (Vikram Goel)

He explains the significance of studying an ice rise. “Ice rises are very small but a very important part in ice flow models. However, they are often neglected. In the past, most ice sheet models use satellite data which are not so high-resolution to get an accurate picture of ice rises,” he says. “Investigating ice rises can add to existing information by adding high-resolution images to big models. It will form part of a bigger study on the evolution of the region. It will provide a much better idea on how the region evolved.”

Goel refers to a joint study by India and Norway conducted 1,000 km east of the ice rise he studied. This team of researchers is studying four or five such ice rises.

The team that studied Blåskimen Island, “one of the larger isle-type ice rises at the calving front at the intersection of Fimbul and Jelbart ice shelves on the Dronning Maud land coast”, has gone into the topography of the ice rise with GPS measurements.

The research paper states that the “ice rise was found to be dome-shaped with a summit at 350m above the adjacent ice shelf” and provide coordinates of its elevation and the speed with which ice flows from the summit towards the flank. “We found good agreement in the spatial patterns of stake-measured surface mass balance between 2013 and 2014, and radar-measured surface mass balance between 2005 and 2014,” the study notes, adding this combined with a range of parameters showed that “Blåskimen Island has been thickening over the past decade.” The authors also conclude that “on larger timescales, we speculated that the summit of the ice rise has been stable within several kilometres at least in the past 600 years, but no longer than several millennia.”

For Goel, the study is a starting point to answer more questions.

“At present, I am studying ice flow models – modelling ice flow inside the ice rise,” he says over the phone from Goa, where he is writing up his second paper from the National Centre for Antarctic and Ocean Research.

He reflects on the time he won the scholarship in 2014. “I was very excited to go but my parents worried about safety,” he says. “It was my supervisor [who is a co-author on this study] who said to me, ‘You will be safer there than you will be in Delhi traffic’.”