[1] It is located on Prince Albert Peninsula in the northwestern part of Victoria Island[A] in Canada's Northwest Territories.

[2] The 25 km (16 mi) wide structure was discovered in 2010 by Brian Pratt, professor of geology at the University of Saskatchewan, and Keith Dewing of the Geological Survey of Canada during an aerial survey of the region.

[3] The structure is estimated to have formed between 450 and 430 million years ago, during the Ordovician period, based mainly on paleomagnetic analysis.

[5] The desert-like landscape of impact structure like Tunnunik can be useful in understanding the geology of other rocky planets such as Mars.

^[A] Not to be confused with the unconfirmed Victoria Island structure in California, United States.