Last update: August 25th, 2019 at 2:00 pm
Astronauts aboard the International Space Station use the Sun’s reflection point to reveal features that are otherwise difficult or impossible to see. Viewed from 290 kilometers (180 miles) above, Earth’s largest river, the Amazon, snakes its way through a floodplain that is more than 32 kilometers (20 miles) wide. Sunglint from the water surface shows the numerous lakes and side tributaries on the floodplain.
The extensive lakes have a longer history to tell. In response to falling sea level during the last Ice Age, the Amazon River cut a canyon tens of meters deep. Sea level rose again with rapid melting of the ice sheets, and to keep pace, the Amazon River bed also has risen. The rising river and bed have filled the canyon with vast quantities of sediment from the distant Andes Mountains in the process. The persistence of the lake depressions shows that this filling process is not yet complete.
Numerous lighter-toned patches of deforestation dot the left margin of the image. Small, bright red patches on either side of the floodplain are open-cast mines where the red soils that underlie the rainforest are exposed.