The Paraná River is South America’s second largest, and the river
and its tributaries are important transportation routes for landlocked
cities in Argentina, Paraguay, Bolivia, and Brazil. This astronaut
photograph shows a 29-kilometer (18 mile) stretch of the Paraná,
downstream of the small city of Goya, Argentina (just off the top left
of the image).
The Paraná River ranges up to 3 kilometers wide along the reach
illustrated in this image. The main channel is deep enough to allow
smaller ocean-going ships to pass north to the capital city of Asunción,
Paraguay, fully 1,200 kilometers (745 miles) inland and well out of the
The river’s dark brown shading indicates a heavy load of muddy
sediment; smaller side channels also carry this mud. Numerous lakes are
typical on active floodplains, and appear here as irregular bodies of
water. Some appear brown, indicating that they probably have been
refilled during recent rises and floods of the active channels.
The Paraná floodplain occupies the entire image; it is so wide—18
kilometers (11 miles) in this view—that its banks are not visible.
Numerous curved, meandering channels are the most prominent
characteristic of the floodplain, indicating prior positions of the
river and its channels. As riverbeds move laterally by natural
processes, they leave remnants of their channels, which appear as lakes
and finally fill with mud. This is an excellent image for illustrating
these meander forms.
From a geological standpoint, it is interesting that almost all of
the old channels are similar in curvature to today’s side channels.
However, almost none of them seem to show prior positions of the main,
wide Paraná channel.
Other astronaut photographs show examples of meandering—on the Rio Negro of southern Argentina, the Mamore River of Bolivia, and the Amazon River of western Brazil.
Astronaut photograph ISS027-E-11058
was acquired on April 9, 2011, with a Nikon D2Xs digital camera using a
400 mm lens, and is provided by the ISS Crew Earth Observations
experiment and Image Science & Analysis Laboratory, Johnson Space
Center. The image was taken by the Expedition 27 crew. The image has been cropped and enhanced to improve contrast. Lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab
to help astronauts take pictures of Earth that will be of the greatest
value to scientists and the public, and to make those images freely
available on the Internet. Additional images taken by astronauts and
cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by M. Justin Wilkinson, NASA-JSC.
- ISS - Digital Camera