Brazilian scientists on Thursday discovered a gigantic underground river thousands of feet below the world's second longest Amazon River.

Researchers from Brazil's National Observatory have found that a subterranean river, which is 6,000 kilometers long, flows 13,000 feet beneath the Amazon.

The river is named after Valiya Hamza, the scientist of Indian origin, who has been studying the Amazon region for more than 40 years. The discovery is part of the work for doctoral student Elizabeth Tavares Pimentel, under the guidance of Hamza.

The Amazon basin is one of the biggest river systems in the world and it covers more than 7 million square kilometers in South America.

The findings show that the Amazon River has two drainage systems: The surface drainage through the Amazon and the flow of groundwater through the deep sedimentary layers, the Hamza.

Hamza is said to be 3,700 miles long, flowing 13,000 feet below the Amazon. Both rivers flow from west to east, but the Hamza flows at only a fraction of the speed of Amazon. The width of the Amazon ranges from 1 kilometer to 100 kilometers whereas the Hamza ranges from 200 kilometers to 400 kilometers.

Hamza flows at a volume of about 3,090 cubic meters per second, as compared to Amazon which flows at a volume of about 133,000 cubic meters. However, the Amazon flows much faster than Hamza.

The river is believed to start from the Acre region under the Andes, and it reaches the sea at Foz do Amazons, flowing through basins of rivers Solimões, Amazon and Marajo before opening out directly into the depths of Atlantic Ocean.

It is likely that this river is responsible for the low level of salinity in the waters around the mouth of the Amazon, said a statement released by the National Observatory.

The latest findings are based on data analysis temperatures of 241 wells drilled by Petrobas in the 1970s and 1980s in the Amazon region. The results obtained allowed the identification of movement of groundwater in depths of 4,000 meters in this region.

Researchers based on the measured changes in temperature down the wells predicted the presence of the underground water by using a mathematical model.

Computer simulations show that the groundwater flow is predominantly vertical to about 2,000 feet deep, but changes direction and becomes horizontal at greater depths.

The river is formed of fresh water, but due to its great depth, its temperature is 30-35 degrees, which is much warmer than the tropically heated Amazon River, Irish Times reported.

Though the studies are in the early stages, Hamza expects to confirm the subterranean flow by the end of 2014.

Amazon is the second longest river in the world and has the largest drainage basin in the world. The bulk of Amazon, which accounts for about one-fifth of the world's total river flow, flows through tropical rainforest. The river merges in to the Atlantic Ocean in a broad estuary about 150 miles wide.

Here is the video explaining the amazing discovery of the underground river beneath Amazon: