Pingos on Our Prairies

Spring, after the snow is gone and before the crops come up, is the best time to look for pingos.  What are pingos?  They are a geological formation fairly unique to the Canadian Arctic, but also known, in miniature form, to speckle the landscape in the Peace Country.

Pingos are cone-shaped mounds with cores of ice, formed when the pressure of subterranean water and expanding permafrost pushes up whatever lies above.  Sometimes the soil from the centre of the mound falls out to the edges, making a ridge around the outside of the cone.  Then, if the peak collapses, the formation looks like a doughnut.  It may fill with water to make a shallow pond in the spring.  Pingos are also called ice-cored hills or ice-shaped ring forms and patterns.

That’s about all that’s known about them, at least all that is easily found out.  Near Tuktoyaktuk you can see giant ice-cored mounds at Pingo Canadian Landmark, which was suggested for one of the Seven Wonders of Canada, but the neither the site nor the formations are well known.  Even to geologists, pingos are obscure.

Did you know that we have these rare formations right here near Spirit River?  If you’re a farmer, you’ve probably navigated around them.  There are a lot, and this excerpt from an article called Ice-Shaped Ring-Forms in Western Canada: their airphoto expressions and manifold polygenetic origins in Quaternary International (September 2000) lists several of note (although the coordinates may be  a little off and the pictures are tiny):

Fig. 3. (a) Large gently sloping circular plateau with encircling ring and shallow summit depressions. West of Eaglesham, AB. A21651-20, NTS 83M, Lat. 55°47′ Long. 118°03′. (b) Small doughnut-like mounds around and within a shallow lake, south of Eaglesham, AB. A21651-18, NTS 83N, Lat. 55°46′ Long. 118°50′. (c) Two low domal mounds with encircling concentric ring depressions. Northeast of Dunvegan, AB. AS 5516-222, NTS 83M, Lat. 55°57′ Long. 118°24′. (d) Low domal mound with narrow circular depression near the mound summit. The mound has affected bounding drainage incision (see, also, Fig. 3c). Southwest of Fairview, AB. AS 4314-138, NTS 84D, Lat. 56°02′ Long. 118°37′. (e) Large laccolith-like mound superimposed on a slightly larger round mound, encircling depression, summit breaches and small summit depressions. East of Rycroft, AB. AS 4088-135, NTS 83M, Lat. 55°47′ Long. 118°28′. (f) Group of round and oval mounds centred in moats and the beds of small drained lakes. Northwest of the town of Spirit River, AB. A 8099-98, NTS 83M, Lat. 55°49′ Long. 118°55′. (g) Airphoto showing the locations of several pingo-like mounds, 100 to 200 m in diameter, surrounded by moats and small drained lakes. Leaders point to several mounds, which are difficult to detect in 2-D at the airphoto scale. One mound (circled) has a star-like summit crater. North of Spirit River, AB. A 21651-26, NTS 83M, Lat. 55°48′ Long. 118°50′.

The article was written by J.D. Mollard.  If you want to read more, it will cost you $35.

If you use Google Earth have a look at those places mentioned, or just hover in the Eaglesham area.  You’ll see a strange, blistered landscape, with some doughnut-shaped formations. Are they thousands of pingos?  At least some of them are, and maybe future geologists will tell us more.

If you know any interesting things about the Peace Country, share it with everyone by posting an article on Town Spirit!  It’s so easy, you won’t believe it.  All you have to do is email your post, pictures, ideas or ads to townspirit@hotmail.com.

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One Response to Pingos on Our Prairies

  1. Anonymous says:

    Wow, that looks really odd on google earth! This is something I had never heard of before.

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