Over the past few years, due to higher summer temperatures, scientists have seen an increase in landforms that are caused by melting ice in the permafrost.

Over the past few years, due to higher summer temperatures, scientists have seen an increase in landforms that are caused by melting ice in the permafrost. (Melissa Ward Jones/McGill University)

Permafrost degradation spreads in High Arctic

Share

Polar deserts in Canada’s High Arctic are undergoing rapid changes as increases in summer air temperatures lead to permafrost thaw, leaving giant horseshoe-shaped pockmarks on the barren terrain, according to a new study.

The study by McGill University researchers, published recently in Environmental Research Letters, presents close to 30 years of aerial surveys and extensive ground mapping of the Eureka Sound Lowlands area of Ellesmere and Axel Heiberg Islands, Canada’s northernmost Arctic islands, located at approximately 80 °N.

The research focuses on these horseshoe-shaped landforms, also known as thaw slumps, that develop when the ice within the permafrost melts and the land slips down.

While thaw slumps are very common in the lower Arctic latitudes, researchers had assumed the High Canadian Arctic, where average annual ground and air temperatures are -16.5 C and -19.7 C, respectively and the permafrost is over 500 metres deep, would be more immune to the effects of warmer temperatures, said Melissa Ward Jones, the study’s lead author and a PhD candidate in McGill’s Department of Geography.

“For a long time we thought that areas that permafrost areas that are closer to the thawing point… further south were the most sensitive to change because they were closer to that zero degree thawing point,” Ward Jones said in a telephone interview from Fairbanks, Alaska.

“But what my study is showing is that, no, these places aren’t immune to climate change.”

(click to listen to the interview with Melissa Ward Jones)

Listen
Scientists had not expected to see the spread of these landforms, known as retrogressive thaw slumps, in the high Arctic because of the extremely cold ground and air temperatures. (Melissa Ward Jones/McGill University)

Scientists had not expected to see the spread of these landforms, known as retrogressive thaw slumps, in the high Arctic because of the extremely cold ground and air temperatures. (Melissa Ward Jones/McGill University)

Even a slight increase in summer temperatures is enough to trigger a bigger permafrost thaw, she said.

Despite short Arctic summers, the thaw season, which lasts for just 3-6 weeks a year, leads to the development and expansion of slumps, which could have major implications for northern infrastructure, Ward Jones said.

“I think it’s a wakeup call that change is happening in these areas that are really far north,” Ward Jones said.

There has been a widespread development of retrogressive thaw slumps in high Arctic polar deserts over a short period, particularly during the unusually warm summers of 2011, 2012 and 2015, the research shows.

“When we see these widespread increases, these large jumps in numbers going from 100 active slumps to over 200 active slumps, that means something is going on bigger regional scale, so we’re linking this with increases in summer temperatures,” Ward Jones said.

McGill researchers have been studying the high Arctic polar deserts for close to 30 years, mapping the landscape within the Eureka Sound Lowlands, Ellesmere and Axel Heiberg Islands.

McGill researchers have been studying the high Arctic polar deserts for close to 30 years, mapping the landscape within the Eureka Sound Lowlands, Ellesmere and Axel Heiberg Islands. (Melissa Ward Jones/McGill University)

This happens because the terrain in Canada’s Arctic polar deserts has very little vegetation and organic cover to insulate it from increased summer temperatures, Ward Jones said.

“Where we are on Ellesmere Island permafrost is more in equilibrium with climate, so any increase in summer temperatures if you reach a new maximum summer temperatures, you’re going to have an increase in your thaw depth – the layer of soil at the surface that goes above zero every summer – and if you have ice-rich permafrost, which we do have in these areas, the ice within the permafrost is going to melt,” she said.

Wayne Pollard, a professor in McGill’s Department of Geography and co-author on the study, said their research clearly demonstrates the complex nature of ice-rich permafrost systems and climate-permafrost interaction.

“Furthermore, it raises concerns about the over simplification of some studies that generalize about the links between global warming and permafrost degradation,” Pollard said in a statement.

Share
Categories: Environment
Tags: , , , ,

Do you want to report an error or a typo? Click here!

@*@ Comments

Leave a Reply

Your email address will not be published. Required fields are marked *

 characters available

Note: By submitting your comments, you acknowledge that Radio Canada International has the right to reproduce, broadcast and publicize those comments or any part thereof in any manner whatsoever. Radio Canada International does not endorse any of the views posted. Your comments will be pre-moderated and published if they meet netiquette guidelines.

Netiquette »

When you express your personal opinion in an online forum, you must be as courteous as if you were speaking with someone face-to-face. Insults and personal attacks will not be tolerated. To disagree with an opinion, an idea or an event is one thing, but to show disrespect for other people is quite another. Great minds don’t always think alike—and that’s precisely what makes online dialogue so interesting and valuable.

Netiquette is the set of rules of conduct governing how you should behave when communicating via the Internet. Before you post a message to a blog or forum, it’s important to read and understand these rules. Otherwise, you may be banned from posting.

  1. RCInet.ca’s online forums are not anonymous. Users must register, and give their full name and place of residence, which are displayed alongside each of their comments. RCInet.ca reserves the right not to publish comments if there is any doubt as to the identity of their author.
  2. Assuming the identity of another person with intent to mislead or cause harm is a serious infraction that may result in the offender being banned.
  3. RCInet.ca’s online forums are open to everyone, without regard to age, ethnic origin, religion, gender or sexual orientation.
  4. Comments that are defamatory, hateful, racist, xenophobic, sexist, or that disparage an ethnic origin, religious affiliation or age group will not be published.
  5. In online speak, writing in ALL CAPS is considered yelling, and may be interpreted as aggressive behaviour, which is unpleasant for the people reading. Any message containing one or more words in all caps (except for initialisms and acronyms) will be rejected, as will any message containing one or more words in bold, italic or underlined characters.
  6. Use of vulgar, obscene or objectionable language is prohibited. Forums are public places and your comments could offend some users. People who use inappropriate language will be banned.
  7. Mutual respect is essential among users. Insulting, threatening or harassing another user is prohibited. You can express your disagreement with an idea without attacking anyone.
  8. Exchanging arguments and opposing views is a key component of healthy debate, but it should not turn into a dialogue or private discussion between two users who address each other without regard for the other participants. Messages of this type will not be posted.
  9. Radio Canada International publishes contents in five languages. The language used in the forums has to be the same as the contents we publish. The usage of other languages, with the exception of some words, is forbidden. Messages that are off-topic will not be published.
  10. Making repetitive posts disrupts the flow of discussions and will not be tolerated.
  11. Adding images or any other type of file to comments is forbidden. Including hyperlinks to other websites is allowed, as long as they comply with netiquette. Radio Canada International  is in no way responsible for the content of such sites, however.
  12. Copying and pasting text written by someone else, even if you credit the author, is unacceptable if that text makes up the majority of your comment.
  13. Posting any type of advertising or call to action, in any form, to Radio Canada International  forums is prohibited.
  14. All comments and other types of content are moderated before publication. Radio Canada International  reserves the right to refuse any comment for publication.
  15. Radio Canada International  reserves the right to close a forum at any time, without notice.
  16. Radio Canada International  reserves the right to amend this code of conduct (netiquette) at any time, without notice.
  17. By participating in its online forums, you allow Radio Canada International to publish your comments on the web for an indefinite time. This also implies that these messages will be indexed by Internet search engines.
  18. Radio Canada International has no obligation to remove your messages from the web if one day you request it. We invite you to carefully consider your comments and the consequences of their posting.

*