Aerial view of The Meeting of Waters looking west, just after departure from Manaus, Brazil.
The Meeting of Waters (Portuguese: Encontro das Águas) is the confluence between the Rio Negro, a river with dark (almost black colored) water, and the sandy-colored Amazon River or Rio Solimões, as it is known the upper section of the Amazon in Brazil. For 6 km (3.7 mi) the river's waters run side by side without mixing. It is one of the main tourist attractions of Manaus, Brazil. The same also happens near Santarém, Pará with the Amazon and Tapajós rivers. This phenomenon commonly takes place in many regions of the world.
This phenomenon is due to the differences in temperature, speed and water density of the two rivers. The Rio Negro flows at near 2 km per hour at a temperature of 28°C, while the Rio Solimões flows between 4 to 6 km per hour a temperature of 22°C.