Canadians across the country mark Remembrance Day
Today Canadians will remember and honour the sacrifice of men and women in uniform who gave their lives in service of the country's values and principles.
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.â€
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.â€
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.â€
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.â€
Today Canadians will remember and honour the sacrifice of men and women in uniform who gave their lives in service of the country's values and principles.
Canada has announced changes to their visitor visa policies, effectively ending the automatic issuance of 10-year multiple-entry visas, according to new rules outlined by Immigration, Refugees and Citizenship Canada.
Toy giant Mattel says it 'deeply' regrets an error on the packaging of its 'Wicked' movie-themed dolls, which mistakenly links toy buyers to a pornographic website.
U.S. President-elect Donald Trump says that Tom Homan, his former acting U.S. Immigration and Customs Enforcement director, will serve as "border czar" in his incoming administration.
If Earth's astronomical observatories were to pick up a signal from outer space, it would need an all-hands-on-deck effort to decipher the extraterrestrial message. A father-daughter team of citizen scientists recently deciphered the message. Its meaning, however, remains a mystery.
Two nephews of the beloved Harry R. Hamilton share stories about his life and legacy.
Since the U.S. Supreme Court’s 2022 Dobbs decision eliminated the federal right to abortion, miscarriage management has become trickier and in some cases, deadlier.
The union representing some 1,200 dockworkers at the Port of Montreal has overwhelmingly rejected a deal with their employers association.
Rod Ashby was desperate to find his wife Kim Ashby after their newly built home in Elk Park, North Carolina, was swept away by Hurricane Helene’s floodwaters in late September and she went missing.
A congestion crisis, a traffic nightmare, or unrelenting gridlock -- whatever you call it, most agree that Toronto has a congestion problem. To alleviate some of the gridlock, the Ontario government has announced it plans to remove bike lanes from three major roadways.
For the second year in a row, the ‘Gift-a-Family’ campaign is hoping to make the holidays happier for children and families in need throughout Barrie.
Some of the most prolific photographers behind CTV Skywatch Pics of the Day use the medium for fun, therapy, and connection.
A young family from Codroy Valley, N.L., is happy to be on land and resting with their newborn daughter, Miley, after an overwhelming, yet exciting experience at sea.
As Connor Nijsse prepared to remove some old drywall during his garage renovation, he feared the worst.
A group of women in Chester, N.S., has been busy on the weekends making quilts – not for themselves, but for those in need.
A Vancouver artist whose streetside singing led to a chance encounter with one of the world's biggest musicians is encouraging aspiring performers to try their hand at busking.
Ten-thousand hand-knit poppies were taken from the Sanctuary Arts Centre and displayed on the fence surrounding the Dartmouth Cenotaph on Monday.
A Vancouver man is saying goodbye to his nine-to-five and embarking on a road trip from the Canadian Arctic to Antarctica.