21 October 2010

The Meeting of Waters

Manaus in Brazil is the largest city in the Brazilian state of Amazonas.  Every year thousands of tourists arrive in the town but no sooner are they there than they jump on to a boat.  The reason?  The city is the closes to a phenomenon known as The Meeting of the Waters or in Portuguese, Encontro das Águas.

Two rivers meet at Manaus – the Rio Negro and the Amazon (or as it is known in the area, Rio Solimões).  The confluence provides us with a rare spectacle – the two rivers contain water which is colored in very different ways.

The Rio Negro has dark water, almost black while the Amazon’s waters are a sandy color.  If they simply met and merged that would be one thing.  However, the waters run side by side for almost four kilometers without merging.  Here is the reason why the tourists of Manaus head for the boats.

There are three reasons for this strange confluence.  The two rivers contain water which differ in terms of the speed at which it travels, density and temperature.  The Amazon flows quickly, at up to six kilometers and hour whereas the Negro is slower at 2km per hour.

That is not all.  The Negro has a temperature of 28 degrees Celcius while the Amazon has a much lower temperature, at 22 degrees.  The combination of these three factors force the water apart for four kilometers and provide us with another of nature’s many wonders.