In 2011 geoscientist Andrés Ruzo went to the Amazon rainforest to investigate anomalies he’d noticed on a heat map. And as his canoe neared the mouth of the mythical “boiling river,” a shaman instructed him to put his hand in the water.
Covering more than 2 million square miles, Amazonia is the world’s largest tropical rainforest. Fed by a blazing sun, torrential rain and a labyrinthine river network, it is a vast wilderness filled with both danger and primeval wonder. Indeed, many ill-prepared travelers have met their end here.
Ruzo, a Ph.D. student at Texas’ Southern Methodist University, heard about the Amazon’s boiling river as a young boy in Lima, Peru. For years he had been rapt by the possibility of it existing.
The legend goes that the conquistadors were lured into the Amazon in search of El Dorado – a mythical city built from gold. The explorers, however, did not return with gold and glory. Instead, those who made it back described man-eating serpents, contaminated waters and, indeed, a boiling river.
This was just legend, or so Ruzo thought. But one day the Peruvian government invited to him to examine some heat maps they’d made. And according to their data, there were some extremely hot springs in the remote Peruvian Amazon.
Intriguingly, there was no explanation behind the heat anomalies. Hot springs are usually fed by volcanic systems, but there are no volcanoes in that part of the country. Despite this, the experts Ruzo consulted dismissed the possibility of the boiling river being real.
However, when Ruzo raised the topic at a family meal, his aunt told him that the legend was based on truth. She even claimed, in fact, to have swam in the river. And so, armed with his aunt’s anecdotes, Ruzo packed his bags and traveled – his aunt in tow – to the city of Pucallpa.
From Pucallpa it was a bumpy two-hour drive to the Pachitea River, an Amazon tributary. From there Ruzo and his aunt rode in a peke-peke – a motorized canoe – half an hour upstream to the mouth of the Boiling River. And it was then that the shaman’s apprentice told him to put his hand in the water.
It was as hot as bath water – but not boiling. Indeed, Ruzo later told a TED Talk audience that he had wondered whether the Boiling River was actually just a “warm stream.” But then his guide took him to a different section – one that was billowing with steam.
Testing the water with his thermometer, the geoscientist confirmed that the average temperature of the river was 187º F. “Dipping my hand into the river would give me third-degree burns in less than half a second,” he later told his TED Talk audience. “Falling in could easily kill me.”
In fact, the four-mile-long river is as hot as 207º F in some sections – hot enough to cook any animal. “So they fall in and the first thing to go are the eyes,” Ruzo added. “Eyes, apparently, cook very quickly. They turn this milky-white color.”
“The stream is carrying them,” the geoscientist continued. “They’re trying to swim out, but their meat is cooking on the bone because it’s so hot. So they’re losing power, losing power, until finally they get to a point where hot water goes into their mouths and they cook from the inside out.”
Naturally, the indigenous Asháninka who live in the area have long known about the Boiling River. According to local myths, its waters were “birthed” by a giant serpent spirit known as the Yucamama, or “Mother of the Waters”. Appropriately, the river’s ancient name is Shanay-timpishka, which translates as a “river that is boiled with the heat of the sun”.
Sometimes after heavy rain the water is cool enough to bathe in; though historically it has more often been avoided. Believed to be a place of immense spiritual energy, the Boiling River was hitherto visited only by the most powerful shamans. And the venerable Maestro Juan Flores is among them.
Allied with a jungle spirit called Mayantu, Flores manages the Mayantuyacu healing center on the river’s banks. He claims the river once cured a gunshot wound that doctors said would leave him permanently crippled.
With Flores’ permission Ruzo was able to conduct the first ever geoscientific investigation into the river. So, scientifically speaking, why was the river so hot? Initially, Ruzo feared that an oil spill or gas leak may have been responsible. However, he soon determined that the river was fed by rainwater.
Ruzo reckons that rainwater travels along underground faults before reemerging as super-heated hot springs. “As we have hot blood running through our veins and arteries, so, too, the Earth has hot water running through its cracks and faults,” he said in his TED Talk.
In fact, the Boiling River may well be the world’s largest thermal river. But it is currently under threat. With the rapid development of Pucallpa, some locals have plundered the forest for lumber, converting it to cattle pasture in the process.
In order to raise the river’s profile Ruzo has authored a book entitled The Boiling River: Adventure and Discovery in the Amazon. Also, fearing that geothermal energy companies may use his research, the geoscientist has withheld his Ph.D.’s publication until the river’s protection is state-guaranteed.
“At a time when everything seems mapped, measured and understood, this river challenges what we think we know,” Ruzo said in his TED Talk. “It has forced me to question the line between known and unknown, ancient and modern, scientific and spiritual. It is a reminder that there are still great wonders to be discovered.” And with any luck, the wonder of the Boiling River will be protected for future generations.