|The Source of the Amazon
The search for the most distant extent of the Amazon river system has been a subject of interest for centuries. Finding the ultimate "source" of a great river is problematic, as there are many ways to define this point. Very often the source is defined by measuring flow rates of different tributaries and following the route upriver along the routes of greatst flow. However, many hostorical definitions of river sources were made without measuring flow rates. The route to the source was chosen by deciding which "looked" like the dominant tributaries. In this work, the "source" of the Amazon is defined as the point at which water must flow the greatest distance to flow into the Amazon River.
The Rio Lloqueta, a small river in the Andes Mountains, is located in southern Peru about 130 kilometers north of the city of Arequipa. Its watershed covers an area of about 100 square kilometers at altitudes up to 5300 meters. This area is the most distant catchment of the Amazon River system. The five main tributaries of the Lloqueta, named Carhuasanta, Silanque, Apacheta, Calomarco, and Ccaccansa, reach almost to the summits of the continental divide. The peaks include Nevado Mismi and Quehuisha.
Field Team Next to Laguna McIntyre
Preliminary field work was performed in July 1997 to visit the Lloqueta
and obtain accurate positions of the river and its tributaries. Portable
GPS receivers were used to collect these data. In July 2000, researchers
returned to the Lloqueta to perform GPS surveying to obtain accurate
position data on the Lloqueta and its tributaries.
Click here to see more images of
the 2000 field expedition.
Maps and Images
Click here to see the maps produced
from this field work.
The three-dimentional views graphically demonstrate the physical structure
of the Lloqueta basin. The first view shows Quebrada Caruasanta and
the perennial ice cover of Nevado Mismi. An overview of the entire
southern part of the Lloqueta drainage basin was also created. GPS data
were draped over the images. A topographic map including the GPS data
collected during field work was also created.
The five main tributaries of the Lloqueta were accurately mapped. Of the
five, Carhuasanta had the greatest length with consistant water flow. The
Apacheta can have longer surface flow, but this stream has been observed
to become dramatically shorter in dry years. The most distant bodies of
standing water are Ticlla Cocha and Laguna McIntyre on Nevado Mismi.
For more information, please contact:
Andrew K. Johnston
National Air and Space Museum
Center for Earth and Planetary Studies