Boggling Baikal

Lake Baikal isn’t just the deepest lake in the world; it’s also the oldest. Most lakes clog up with sediment and disappear after about 50,000 years or so, but at over 2 million years of age, with over four miles of sediment accumulated at the bottom of the lake, Baikal is still going strong. And still more than a mile deep.

The lake holds about one fifth of the world’s fresh water. If you were to drain it, it would take all the world’s rivers (assuming you could re-route them to pour into the Baikal basin) one year to fill it back up.

Or, you could take the water out of the five North American Great Lakes and use them to refill the lake—that would just about do it.