The Yellow Sulfur Pyramids of Canada

Alberta, Canada, has some of the world's largest pyramids. But these weren't megastructures built by ancient peoples for the honor of their leaders, to connect the afterlives of pharaohs with the gods, or to provide a special place of worship for their people. These pyramids are made entirely of yellow elemental sulfur!

Sulfur is currently being harvested in large quantities due to its recovery from tar sand oil and gas in operations in the northwestern U.S. and western Canada. Once the sulfur is removed, the oil and gas companies can try to sell it, but sulfur is down in the markets right now and that means a lot of sulfur is just being stored, in a process called "blocking", where large blocks of elemental sulfur are produced and then stored.

Blocks of sulfur, 25 feet tall (credit: Gord McKenna)

One place where blocking has gone rampant is near the tar sands of Alberta, Canada. As of 2012, oil and gas extraction of sulfur in this region accounted for roughly 1.5 million tons per year of sulfur. At that time, 600,000 tons were being blocked each year. That led one company, called Syncrude, to start building The Great Sulfur Pyramids of Alberta!

These giant pyramids of sulfur blocks can be easily seen in satellite images. Andrew David Thaler, writing in Southern Fried Science, calculated from images and data that the largest of the sulfur pyramids was at 2,840,000 cubic meters in volume back in 2012 (it's continued to grow since then). In comparison, the Great Pyramid of Giza is only 2,580,000 cubic meters in volume. With the current rate of growth of the Great Sulfur Pyramids of Alberta, they're on track to become the largest human-made structures ever (by volume). Here's a comparison of bases of the Great Pyramid and the largest of the sulfur pyramids:

Comparisons, from Southern Fried Science

Those are some huge pyramids! I think I'll have to throw a visit to these pyramids on my travel list. Just to see those large, yellow structures of sulfur would be intriguing, even if their presence is due to the fact that we're now pushing the limits on extraction of hydrocarbons from the Earth.