Hamza River

The Hamza River (Portuguese: Rio Hamza) is an unofficial name for what looks like a slowly moving aquifer in Brazil and Peru. It is about 6,000 kilometres (3,700 miles) long and lies nearly 4 kilometres (2.5 miles) deep. This amazing "river" was announced in 2011 during a meeting of the Geophysical Society in Rio de Janeiro.

The name Hamza River honors Indian scientist Valiya Mannathal Hamza, who works at Brazil's National Observatory. He has studied this area for forty years. The Hamza "river" and the nearby Amazon River are special because they flow at different levels deep inside the Earth, making a rare twin-river system.

Description

The Hamza River and the Amazon River are the two main water systems in the Amazon Basin. The Hamza River flows very slowly, about 3,000 cubic metres of water every second. This is only 3% of what the Amazon River moves. It runs from west to east, deep underground, almost 4,000 metres below the surface. It follows a path similar to the Amazon River. The Hamza starts in the Andes mountains and ends in the Atlantic Ocean, far beneath the ground. The water in the Hamza River has a lot of salt in it.

Unlike the Amazon, which can be up to 100 kilometres wide, the Hamza is much wider, ranging from 200 to 400 kilometres wide. But it moves extremely slowly—less than 1 millimetre per second. Scientists found the Hamza by studying seismic data and temperature changes deep in old oil wells.

Geology

Several geological factors helped create the Hamza River. The porous and permeable sedimentary rocks allow water to sink deep underground. East–west trending faults and the karst topography along the northern border of the Amazon basin may help supply water to the river. If the impermeable rocks stop the water, the land’s slope directs it toward the Atlantic Ocean.

Unlike the Hamza River, underground rivers in Mexico’s Yucatán Peninsula and the Puerto Princesa Subterranean River National Park in the Philippines formed because water dissolved the carbonate rock, creating underground river systems.

Research status and debate

Scientists found clues about the Hamza River using old temperature data from oil wells drilled long ago by Petrobras. They think there is a large flow of water moving very slowly deep underground. This water moves so slowly that it is hard to study directly. The scientists use the word "river" to help people understand, but it is not like a regular river you see on the surface.

They shared what they found at a big science meeting in Rio de Janeiro in 2011. At that time, they had not yet written about it in a science journal. The scientists said their work is still new and they hope to learn more about this hidden water flow in the years to come.