Whitecourt
Key facts
- Country
- Canada
- Diameter
- 36 m
- Age
- about 1,100 years
- Location
- 54.00° N, 115.60° W
A small, round, tree-filled crater about 36 m across and a few metres deep in the boreal forest of Alberta.
The Whitecourt crater, in the forests of west-central Alberta, is one of the smallest and youngest meteorite craters known in Canada. It is only about 36 m across, but it is very well preserved, a round hollow in the forest floor surrounded by spruce and aspen.
The impact. About 1,100 years ago an iron meteorite struck the ground here. It was probably about 1 m across. The impact dug out a bowl about 36 m wide and a few metres deep. Trees later grew inside it, and the crater became hidden in the forest, unknown to scientists until the twenty-first century.
Discovery. In 2007 the crater was brought to scientists' attention and quickly confirmed as an impact crater. Searches with metal detectors found many fragments of the meteorite in and around the crater, mostly buried in the soil. The meteorite is an iron of group IIIAB, a common type. Most of the fragments are jagged shrapnel, formed when the meteorite shattered on impact.
Dating the crater. The crater's age was measured using radiocarbon dating of charcoal and organic material found beneath the ejecta, the soil thrown out by the impact. Material buried by the ejecta must have been there before the crater formed, giving a maximum age of about 1,100 years. That makes Whitecourt one of the youngest craters in North America.
A protected site. In December 2008 the Government of Alberta designated the crater a Provincial Historic Resource, protecting it by law. It is illegal to search for or remove meteorites from the site. The site is managed to protect both the crater and the forest around it, and anyone hoping to visit should check current access arrangements first.
Why it matters. Whitecourt is an example of the smallest kind of crater that iron meteorites can make. Small iron meteorites are usually slowed to their terminal speed by the atmosphere and land without making a crater. Only those that are large enough, roughly a metre or more across, keep enough of their speed to blast out a crater. Studying sites like Whitecourt helps scientists understand the boundary between meteorites that simply land and those that explode on impact.
Finding young craters. Whitecourt also shows that young impact craters can remain hidden in forested regions. Many more small craters may lie undiscovered under forests, especially in places like Canada and Siberia. New techniques, such as airborne laser scanning, which can map the ground beneath trees, may help to reveal them.
Did you know?
Whitecourt was unknown to science until 2007.
It is protected as a Provincial Historic Resource, so meteorite hunting there is illegal.
The crater was made by an iron meteorite probably about a metre across.