This year has been a memorable one for great Amazonian discoveries. In posts published throughout the last 12 months, I waxed enthusiastic about fantastical phenomena ranging from glow-in-the-dark mushrooms  and exploding zombie ants  to never before contacted Indian tribes . However, 2011 was also memorable for the discovery of the Hamza River.
If you thought the Amazon was big, you haven’t seen the Hamza.
Chances are, however, that you won’t.
This is because despite the fact that the Hamza River is roughly as long as the world’s second longest river – not to mention much wider – the Hamza is a subterranean river.
Not unlike a (very deep) shadow, the Hamza follows the same East-West route taken by the Amazon as it flows 6,000 km (3,700 miles) from the Andes all the way down to the Atlantic Ocean. Only it does so at a depth of 4 km (2.5 miles) beneath its more visible alter rio.
Matters of profundity aside, there are other differences between the two rivers. First of all, the width of the Hamza, between 200 and 400 km (125 and 250 miles), is much greater than the Amazon, which ranges from 1 to 100 km (0.6 to 63 miles). Secondly, the waters of the Hamza travel through porous stones at a much slower rate (an estimated 3,900 cubic meters (13,000 cubic feet) per second) than the mighty Amazon (whose flow rate is 133,000 cubic meters (436,000 cubic feet) per second).
As a result, despite its size, the Hamza probably holds less than 3 percent of the water that flows through the Amazon, which claims the title as most voluminous river on the planet. (Just for reference, the Amazon’s discharge into the Atlantic in one day is enough to supply New York City’s freshwater needs for 9 years!)
The Hamza’s discovery was made by a team of Brazilian scientists led by Valiya Hamza and Elizabeth Tavares Pimentel of the Geophysics Department of Brazil’s National Observatory . Their results were based on data collected from 241 abandoned wells which had been drilled in the Amazon, during the 1970s and ‘80s, by Brazilian oil and gas giant, Petrobras  .
While the results of the scientists’ findings were recently presented at this year’s International Congress of the Brazilian Geophysical Society in Rio de Janeiro, studies are still in their preliminary stages. According to some critics, the Hamza’s massive size and slow speed means it’s unlikely to possess the continuous flow of a “real” river. Professor Hamza himself says official confirmation of his namesake river will only come in 2014.
Already, however, the findings are significant in that they show that the Amazon rainforest possesses not one drainage systems, but two – the Amazon and the Hamza. They also underscore how many amazing discoveries still remain to be made within the borders of the world’s largest and most biologically diverse rainforest.