Re: Image comments for Impact crater, northern Canada. Photo taken from Space Shuttle Columbia (1983)
Lake Manicouagan, northern Québec.
"The meterorite that created this crater hit so hard that ejecta ended up... in Great-Britain! This impact, 214 millions years old, has probably done a lot of damage. It is believed it was a 5-km meterorite.
Biologists have noticed a massive extinction of animal and plant species which occured about 200 million years ago. It is after that exctinction event that reptiles, and among them the dinosaurs, could establish themselves as the dominant species on our planet.
Today, lake Manicouagan is the scar of this prehistoric cataclysm. The ring-shaped lake is in fact a crater, 100 km in diameter. The crater, like the rest of Québec territory, has been subjected to intense erosion following the passing of glaciers. Lake Manicouagan, through the river of the same name, empties into the St-Lawrence river 483 km further south. It is on this powerful river that Hydro Québec has built several hydroelectric powerplants, one of which being the world's largest multi-arch dam, the Daniel-Johnson dam (aka Manic-5)."
source (in French):
Note -- This photo is also available, larger and in more colors and spectra, on the NASA Earth Observation site.
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