Lake Agassiz Flood 9000 BCE

Canada once held an ancient glacial lake the size of the Black Sea, known as Lake Agassiz. Larger than all the Great Lakes combined, it remained trapped by an ice sheet until it broke around 9,000 years ago. When the lake drained, it unleashed enough water into the Atlantic to raise global sea levels by 3 to 9 feet, cool the Northern Hemisphere by about 3°C, and transform Britain into an island. Many believe it even fueled ancient global flood myths. Today, you can still see the beaches left behind by the vanished lake.

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