Widespread permafrost degradation seen in high Arctic terrain

Widespread permafrost degradation seen in high Arctic terrain
Due to record summer temperatures in recent years, high Arctic polar terrain is changing. Credit: Melissa Ward Jones

Rapid changes in terrain are taking place in Canada's high Arctic polar deserts due to increases in summer air temperatures.

A McGill-led study 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 located at approximately 80 °N. The research focuses on a particular landform (known as a retrogressive thaw slump) that develops as the ice within the melts and the land slips down in a horseshoe-shaped feature. The presence of these landforms is well documented in the low Arctic. But due to the extremely in high Arctic polar deserts (where average annual ground and air temperatures are -16.5 °C/2.3 °F, and -19.7 °C /-3.46 °F, respectively), and the fact that the permafrost is over 500 metres (or about 1/3 of a mile) thick, it had been assumed this landscape was stable. But the McGill-led research team found that this has not been the case.

"Our study suggests that the warming climate in the high Arctic, and more specifically the increases in summer air temperatures that we have seen in recent years, are initiating widespread changes in the landscape," says Melissa Ward Jones, the study's lead author and a Ph.D. candidate in McGill's Department of Geography.

Widespread permafrost degradation seen in high Arctic terrain
Scientists from McGill University have been mapping the high Arctic polar deserts for almost thirty years. In the past few years, as the permafrost melts, they have seen an increase and spread of landslide-like features in an area where they had believed extremely cold temperatures would ensure the stability of the land. Credit: Melissa Ward Jones

The research team noted that:

  • There has been a widespread development of retrogressive thaw slumps in high Arctic polar deserts over a short period, particularly during the unusually of 2011, 2012 and 2015;
  • That the absence of vegetation and layers of organic soil in these polar deserts make permafrost in the area particularly vulnerable to increases in summer air temperatures;
  • Despite its relatively short duration, the thaw season (which lasts for just 3-6 weeks a year) initially drives the development of slumps and their later expansion in size, as their headwall retreats; and
  • Over a period of a few years after the initiation of slumps, study results suggest various factors related to terrain (e.g. slope) become more important than air in maintaining active slumps.
In recent years, high summer temperatures have started melting the ice in the permafrost. As a result, land forms are changing unexpectedly. Credit: McGill University

"Despite the cold polar conditions that characterize much of the high Arctic, this research clearly demonstrates the complex nature of ice-rich permafrost systems and climate-permafrost interaction," adds Wayne Pollard, a professor in McGill's Department of Geography and co-author on the study. "Furthermore, it raises concerns about the over simplification of some studies that generalize about the links between global warming and permafrost degradation."

Explore further

A slippery slope: How climate change is reshaping the Arctic landscape

More information: Melissa K Ward Jones et al, Rapid initialization of retrogressive thaw slumps in the Canadian high Arctic and their response to climate and terrain factors, Environmental Research Letters (2019). DOI: 10.1088/1748-9326/ab12fd
Journal information: Environmental Research Letters

Provided by McGill University
Citation: Widespread permafrost degradation seen in high Arctic terrain (2019, May 23) retrieved 22 August 2019 from https://phys.org/news/2019-05-widespread-permafrost-degradation-high-arctic.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Feedback to editors

User comments

May 23, 2019
But, but, but... Warming denialists have been saying for more than a decade now that the Earth has entered into a new glacial period and that the sun is going out and we are all going to freeze to death unless we fill the air with industrial pollution.

They wouldn't be lying, would they?

Why would they lie?

May 23, 2019
Funny how they use the word degradation for something that's good. Less permafrost is a good thing.

And V4V you're insane, just claim they are Russian bots already you lunatic.

May 23, 2019
It's beyond amusing, just how stupid the AGW Cult believe their Chicken Littles are.
That entire region is above a geothermal hotspot.

May 24, 2019
Moreover, why are banks still giving out 30 year mortgages in Miami? According to the alarmist BS, Miami will be underwater in less than 30 years. But banks seem to think they're full of chit too.

May 26, 2019
It wouldn't surprise me that these AGW Cult morons trampling about doing their "research", damage the thin, fragile vegetation thus making it vulnerable to runoff.

May 26, 2019
In Alaska, we once had Obama talking to a Native Village near the coast explaining how global warming was responsible for the rise in their Ocean level. Problem was, their ocean levels are actually falling in Alaska, because, as the glaciers melt and pull back from the last ice age, they weigh down less heavily on the land and it rises faster than the ocean levels rise, causing the waterline to fall.

What's more, it's not getting much warmer in the Arctic. Didn't it just snow in Arizona, in late May? Can they give it a rest?

This is all about fooling middle class and poor people into believing they should bear the loss of goods and services resulting from peak oil. Until the folks pitching this nonsense start talking about banning private jets and capping all the old and new oil drilling sites that are leaking methane (a much bigger greenhouse gas than CO2), even the rich people selling this stuff don't believe it.

It's a croc of bankster crap.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more