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Amazon river: environmental factors that control its dissolved and suspended load
Science (New York, N.Y.)
|June 30, 1967
Summary
Physical weathering in the Andes Mountains dictates the Amazon River's suspended solids composition and discharge amounts. This process impacts both wet and dry seasons, controlling riverine and mouth outputs.
Area of Science:
- Geochemistry
- Hydrology
- Sedimentology
Background:
- The Amazon River is a major global sediment and solute transporter.
- Understanding the factors controlling its discharge is crucial for global biogeochemical cycles.
- The influence of Andean weathering on Amazonian sediment and solute loads requires detailed investigation.
Purpose of the Study:
- To analyze the composition and quantity of suspended solids and dissolved salts discharged by the Amazon River.
- To determine the primary environmental controls on these discharges.
- To assess the seasonal variations (wet and dry) in riverine and mouth outputs.
Main Methods:
- Systematic sampling of the Amazon River, its mouth, and 16 tributaries.
- Analysis of physical weathering processes in the Andean source region.
- Chemical and physical analysis of collected water and sediment samples.
Main Results:
- Physical weathering in the Andes Mountains is the dominant factor controlling Amazonian discharge.
- Both the composition of suspended solids and the amounts of dissolved salts and suspended solids are directly influenced by Andean weathering.
- Seasonal variations (wet and dry) do not alter the fundamental control of Andean weathering.
Conclusions:
- Andean physical weathering is the key driver of the Amazon River's sediment and solute discharge.
- The river's output is a direct reflection of its mountainous headwater environment.
- This finding has significant implications for understanding sediment transport and chemical weathering on a global scale.
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