Establishing the section of the river from which the river flows has caused immense difficulty for the common researcher because the necessary criteria are so rarely found in one place. There are no unambiguous rules, but in classifying rivers hydrologists typically take into consideration the size of the flow or quantity of water that passes a given point in one second. Moreover, they measure its length, the size of the river basin, the steepness of the channel and other less important elements.
Since the times of Humboldt, the source stream of the Amazon was believed to be the Marañón. In 1934 Peruvian Gerardo Dianderas put forward the argument that the Ukajali was the true source. That thesis later gained approval among geographers and, more importantly, was accepted by the Geographic Society in Lima, which emphasized that the river “actually carries less water, but is supported by traditions immortalized in the history and culture of the region.”
In later years in the Cordillera Chila, in the province of Cailloma in southern Peru, there were many explorers who formulated various controversial hypotheses concerning the source without a foundation in hydrological research of any kind. French explorer Michel Perrin claimed in 1953 that the source could be found on the Huagra Mountain, while English journalist Nicholas Asheshov and parachutist John Ridgway believed that the mountain in question was Minaspata and yet others pointed to the Vilafro Lake or the Huarajo stream.
In 1969 Prof. Carlos Peñaherrera del Águila, claimed that the location under discussion was located in Nevado Mismi. Two years later cartographers from National Geographic Magazine identified on maps that the farthest point from the mouth of the Amazon, and therefore the place where the river was born, was Nevado Mismi, the place mentioned by Peñaherrera . There the source of the Carhuasanta stream can be found. A photographer from the same publication, Loren McIntire, reached this spot and without taking any measurements of the streams in the vicinity of the source “sealed” the hypothesis of the magazine with her stamp of approval. Soon she propagated the localization, although it never gained acceptance from the appropriate Peruvian institutions.
Over two years of intensive research, my companions spent a great deal of time on in-depth analysis and interpretation of the water phenomenon shown on radar images and taken from the air at various periods of time. Very costly satellite photos with greater resolution commissioned for this purpose provided more opportunities for interpreting changes in the humidity of the terrain. This allowed them to collect basic material for field research.
Why would anyone want to organize a costly expedition to the farthest reaches of the world in search of „white spots” if it can be done from space? Today’s satellites are actually able to control every square meter of the Earth’s space. However, pictures of astounding resolution, frequently richer in information than topographical maps, can serve only as valuable comparative or supplemental material. They can inspire scientists to continue research efforts, but in themselves rarely form the basis for discovery. Today, much like hundreds of years ago, the irreplaceable actor in the exploration of the Earth is man, his talent for research, passion and patience, entrepreneurial spirit and endurance.
In the summer of 1966 we arrived at the research site. On July 16 the expedition „Amazon Source ‘96” reached its base camp not far from Cailloma, at an elevation of 4,800 meters above sea level and 200 kilometers from Cuzco.
It was very cold, the thermometer indicating just a few degrees above zero. Adding insult to injury a strong, gusty wind froze the marrow in our bones. Silence and loneliness dominate in this vast valley, covered sparsely in vegetation and surrounded by the unearthly peaks of the Andean Cordillera, whose majesty pales only when compared to that of the Himalayas. The landscape is unsettling and at the same time startlingly beautiful. This corner at the end of the world, windswept and tormented by heavy rain and hailstorms, is also bathed by a sun that is able to transform human skin into parchment. It is akin to a lost world that has not changed since the beginning of creation.
The primary focus of our detailed research is measuring the streams in the upper section of the Lloqueta River, an extension of the Apurimac. A spider web of delicate water streamlets represents an unusually complicated hydrological situation. We have to measure their length and the average discharge of water, the volume of water passing by a fixed point along the river in a given amount of time. Only in this way, by eliminating one stream after another and moving methodically upstream, will we be able to locate the stream that gives the Amazon its start.
The first task is a reconnaissance of the Carhuasanta ravine. Soon we discover that its „competitor” the Apacheta contains two times its flow. The latter river is also more important than the Sillanque and Ccaccansa. Admiral Faura underlines that it has less of a descent, the valley larger and at a lower elevation, as well as the fact that where it encounters other streams it maintains its previous direction.
Without abandoning caution we reach the conclusion that the Apacheta is the section from which the Amazon springs. Now we have to reach its source. We climb slowly up the mountain path, which during the times of the Incas was one of the communication networks cutting across the Andes. With great effort we breathe the thin air that contains nearly half of the oxygen that is present at sea level. The great valley, which begins at the foot of the mountain chain, is gradually narrowing. This deserted land is harsh, inhospitable and barren of any traces of vegetation. Only the rocky stream bed, flooded when the water level reaches its peak, is covered in a delicate carpet of green. The Apacheta becomes increasingly flat and narrow. Its width does not exceed one meter.
Close to the pass on Nevado Quehuisha a green oasis can be seen that contrasts sharply with the gray barrenness surrounding it. We are at the source. In a marsh hidden by clumps of grass and tiny bushes an underground water source bubbles to the surface. GPS indicates our geographical coordinates: 15°31’05” S by 71°45’55” W, and an elevation of 5,170 meters above sea level. Strangely, of the glacier and eternal snows that are visible in aerial photos taken 20 years ago, there is no longer any sign.
The mother of all rivers is born inconspicuously. A delicate stream trickles its way among the rubble and gravel. A few dozen meters lower it resurfaces again and then winds along, like a snake, lazily down the slope. Farther on it becomes a wild mountain river and then transforms into a great water artery that flows through a wide channel across the largest alluvial plain on Earth, reaching the Atlantic Ocean six weeks later.
In our report we take into account that the Apacheta is no shorter than its „main competitor,” the Carhuasanta and can be found at the same elevation above sea level at the border of the main watershed. Moreover, the relative discharge, the volume expressed in liters per second per square kilometer of the basin, testifies to hydrological activity. In this respect the Apacheta has no equal. It is significant that our flow measurements were taken during the dry season at a time when the water level is at its lowest. The Quechua Indian accompanying us confirmed that the Apacheta carries water year round and, as the older generations say, it always flows from the same place.
On November 19, 1999 at a press conference held by the Geographic Society in Lima, its president Dr. Eduardo Bedoya Lazarte stated: „The expedition ‘Amazon Source ‘96’ proved conclusively that the Amazon gets its beginning in the Quehuisha mountains. Our objective is now to propagate this discovery among all geographic-cartographic institutes worldwide.” No other competitive thesis put forward by other explorers has ever been accepted by this competent institution.
In terms of length, the Amazon turns out to be longer than the Nile. The lengths of great rivers given to date in the literature were based on maps of varying accuracy. The Nile, examined on a map at a scale of 1:250,000, has a length of 6,468 km, while 6,671 kilometers at 1:100,000. The Amazon has been analyzed on a rather imprecise map (1:1,000,000), because no others were available, where its course is strongly generalized and where the smaller loops are invisible. On this map the river measures 6,516 km. In contrast to the linear course of the Nile, the South American river wends its way over countless bends in a meandering pattern. If the length of both rivers were evaluated at a scale of 1:100.000, there would be no doubt of the Amazon’s greater length.
The river current is constantly modeling new bends. As a result of bend migration and the overflow of meanders during the flood season, the Amazon changes the course of its channel. Short-cuts are always accompanied by an extension created by the formation of new loops. Brazilian scientists claim that the preeminence of the Amazon is unquestionable even in the rainy season when the river floods and frequently flows “cross-country,” shortening its own course.
Calculating its length is also encumbered by difficulties in defining the river’s course and its funnel-like exit into a delta equal in size to 1/3 of Italy, where its end is hard to identify. Prof. Azis Ab’Saber, a Brazilian geological authority, believes that „In light of hydrological and geomorphological complexity, both mouths of the Amazon, both northern and southern (differing by 302 km), should be treated equally. Since hydrology assumes that the source is the point farthest from the mouth, it is understandable that the length of the river should be measured from the longest branch near the mouth.” In 1984 famous oceanographer Jacques Yves Cousteau announced that the Amazon stretched over a distance of 7,025 km.
The definitive lecture in determining the length of the Amazon was given in 2005 by scientists from the Instituto Nacional de Pesquisas Espaciais, the Brazilian Institute of Space Research in Sao Jose dos Campos. Paulo Roberto Martini, while conducting teledetection research on its dimensions using the Landsat satellite, estimated that the river’s length amounts to 7,040 km, while that of the Nile at 6,857.