۴ý

Skip to main content

Antarctic ice sheets can retreat by up to 600 metres a day during warming periods: study

Landsat 8 image depicting the highly dynamic SCAR Inlet Ice Shelf, Antarctic Peninsula, and sea ice production offshore. ©NASA/USGS, processed by Dr. Frazer Christie, Scott Polar Research Institute, University of Cambridge) Landsat 8 image depicting the highly dynamic SCAR Inlet Ice Shelf, Antarctic Peninsula, and sea ice production offshore. ©NASA/USGS, processed by Dr. Frazer Christie, Scott Polar Research Institute, University of Cambridge)
Share

Massive ice sheets are capable of shrinking at a rate that is significantly faster than previous thought — 20 times faster, depending on the period of climate warming and the state of the seafloor, according to a new study.

Researchers pored over high-resolution images of the seafloor and found that in the past, a massive ice sheet retreated by up to 600 metres a day during one of the most significant warming periods of Earth’s history.

The study, , looked at data pertaining to a former ice sheet that extended out from Norway until it retreated around 20,000 years ago, at the end of the last Ice Age.

“Our research provides a warning from the past about the speeds that ice sheets are physically capable of retreating at,” Christine Batchelor, with Newcastle University, “Our results show that pulses of rapid retreat can be far quicker than anything we’ve seen so far.”

In order to track the path of a long-gone ice sheet, researchers looked at incredibly detailed images of the sea floor which showed more than 7,600 ridges that marked the sheet’s path.

Called “corrugation ridges,” these patterns in the sea floor are less than 2.5 metres in height and can be as close as 25 metres apart or as far as 300 metres. According to scientists, these ridges were formed by the tides as the edge of the ice sheet moved, with each low tide depositing seafloor sediments into a ridge. Since the tide came in and out twice a day in this area, scientists were able to measure how far the ice sheet had retreated in a day by looking at the ridges in pairs of two.

Researchers found that this specific ice sheet, which was more than 30,000 square kilometres in size, had retreated at a speed which ranged from 50 to 600 metres a day.

It’s a rate of ice sheet collapse that is much faster than any ice sheets see from satellites or estimated based on Antarctica land mass changes.

This information helps to inform models which lay out how the globe’s ice sheets could change in future warming events. It’s invaluable to know what degree of warming could cause such a rapid retreat of ice sheets as the planet continues to warm due to human-driven climate change.

The circumstances of this ice sheet’s retreat were far different than today, as this was at the end of an Ice Age. But it still provides insight on how ice sheets are capable of shrinking quite rapidly.

“This shows how rates of ice-sheet retreat averaged over several years or longer can conceal shorter episodes of more rapid retreat,” Julian Dowdeswell, a professor at the Scott Polar Research Institute at the University of Cambridge and study co-author, said in the release. “It is important that computer simulations are able to reproduce this ‘pulsed’ ice-sheet behaviour.”

Looking at images of the seafloor for this study also gave researchers an insight into how the seafloor itself plays a role in ice sheet retreat. Researchers observed that the periods of fastest daily retreat occurred where the seafloor was flattest, meaning the ice sheet would’ve experienced the least amount of challenge to its movement, and could almost just float along.

“An ice margin can unground from the seafloor and retreat near-instantly when it becomes buoyant,” Frazer Christie, a co-author with the Scott Polar Research Institute, said in the release. “This style of retreat only occurs across relatively flat beds, where less melting is required to thin the overlying ice to the point where it starts to float.”

So how likely are we to see ice sheets retreating at this rapid pace in the coming years? According to researchers, it could soon occur in parts of Antartica. One specific glacier in Antarctica, the Thwaites Glacier, has recently pulled back close to a relatively flat area of seafloor.

“Our findings suggest that present-day rates of melting are sufficient to cause short pulses of rapid retreat across flat-bedded areas of the Antarctic Ice Sheet, including at Thwaites,” Batchelor said. “Satellites may well detect this style of ice-sheet retreat in the near-future, especially if we continue our current trend of climate warming.” 

CTVNews.ca Top Stories

BREAKING

BREAKING

Four people are dead and another is in hospital following a fiery crash in downtown Toronto that happened overnight on Lake Shore Boulevard.

The president and CEO of New Brunswick-based Covered Bridge Potato Chips is taking an 'extended leave of absence' after being charged with domestic violence this past weekend.

BREAKING

BREAKING

Quebec’s Bureau of Independent Investigations (BEI) is investigating after police in Gatineau, Que. shot and killed a man who allegedly stabbed an officer during an investigation.

Local Spotlight

He is a familiar face to residents of a neighbourhood just west of Roncesvalles Avenue.

A meteor lit up our region's sky last night – with a large fireball shooting across the horizon over Lake Erie at around 7:00 p.m.

Residents of Ottawa's Rideauview neighbourhood say an aggressive wild turkey has become a problem.

A man who lost his life while trying to rescue people from floodwaters, and a 13-year-old boy who saved his family from a dog attack, are among the Nova Scotians who received a medal for bravery Tuesday.

A newly minted Winnipegger is hoping a world record attempt will help bring awareness for the need for more pump track facilities in the city.

A Springfield, Ont. man is being hailed a 'hero' after running into his burning home to save his two infant children.

Hortense Anglin was the oldest graduate to make her way across the platform at York University's Fall Convocation ceremony this week. At the age of 87, she graduated with an Honours degree in Religious Studies.

Looking for a scare with good intentions this Halloween season? The ghosts and ghouls of Eganville, Ont. invite families to tour the Haunted Walk at Lekbor Manor.

The image of a sleepy Saskatchewan small town with 'not a lot going on' is a well-known anecdote. However, one Saskatchewan company is hoping to change that – and allow communities both on and off the beaten path to share their stories and advertise what they have to offer.