EPOW - Ecology Picture of the Week

Solifluction on the Slopes

Slope Solifluction, Karo La Glacier
Karo La Pass, Tibet

Explanation:  What are these strange-appearing ridges and lobes, on this high alpine slope?  We are at Karo La Glacier, at the Karo La Pass in southeast Tibet (sometimes spelled Karola).  We visited this place in a previous EPOW episode, regarding how much the glacial ice is receding under a warming climate.  And here is another part of that story. 

The lobes on the slope are the results of solifluction, where the underlying permafrost is intermittently thawing.  Gravity then causes slippage of the so-called "active layer," that upper portion of the soil profile that thaws annually.  Over time, under increased regional warming, the active layer gets deeper, meaning that the thawing occurs in greater depths.  

Location of Karo La Pass and Karo La Glacier in Tibet.

  

Solifluction (sometimes called gelifluction when it is next to a glacier) can be seen in other parts of the high alpine and high arctic environments.  

Following are some examples from arctic Alaska.  

Here is a patchwork of solifluction lobes in Noatak National Preserve in the Brooks Range of arctic Alaska:

Next is an example of broad slope solifluction slippage in Bering Land Bridge National Preserve:

And another example from Bering Land Bridge National Preserve, here shown encroaching on a river floodplain:

And here, a panorama of overlapping solifluction lobes on the slopes of Gates of the Arctic National Preserve:

Solifluction -- a form of geological mass wasting -- is a slow process, compared to our own sensory perception, but it can have major impact on landforms and traversability, particularly off-road "tundra travel" conducted by Native Alaskans when on hunting and fishing outings.   

And temporal changes in solifluction, particularly accelerating changes in lobe distribution and extent, could serve as indicators of the impacts of increased regional warming under climate change.  

Information:
    Benedict, J. B.  1976.  Frost creep and gelifluction features: a review.  Quaternary Research 6(1):55-76.
    Fiolleau, S., S. Uhlemann, I. Shirley, C. Wang, S. Wielandt, J. Rowland, and B. Dafflon.  2024.  Insights on seasonal solifluction processes in warm permafrost Arctic landscape using a dense monitoring approach across adjacent hillslopes.  Environmental Research Letters 19(4):044021.
    Kislov, A., A. Alyautdinov, A. Baranskaya, N. Belova, D. Bogatova, M. Vilulina, I. Zheleznova, and G. Surkova.  2023.  A spatially detailed projection of environmental conditions in the Arctic initiated by climate change.  Atmosphere 14(6):10.3390/atmos14061003.