THE Amazon basin covers more than 7 million square kilometres in South America and is one of the biggest and most impressive river systems in the world. But it turns out that – until now – we have only known half the story.

Brazilian scientists have found a new river in the basin – around four kilometres underneath the Amazon River. The Rio Hamza, named after the head of the team of researchers who found the groundwater flow, appears to be as long as the Amazon but up to hundreds of times wider.

Both the Amazon and Hamza flow from west to east and are around the same length, at 6000 kilometres. But whereas the Amazon ranges from one kilometre to 100 kilometres in width, the Hamza ranges from 200 to 400 kilometres.

An aerial view ... the Amazon river. Photo: AFP

The underground river starts in the Acre region under the Andes and flows through the Solimoes, Amazonas and Marajo basins before opening out directly into the Atlantic Ocean.

The Amazon flows much faster than the Hamza, however, draining a greater volume of water. About 133,000 cubic metres of water flows through the Amazon each second at speeds of up to five metres a second. The underground river’s flow rate has been estimated at about 3900 cubic metres a second and less than a millimetre an hour.

Source: The Sunday Morning Herald Read more