Amazon Sediment Transport and Accumulation Along the Continuum of Mixed Fluvial and Marine Processes

• Published in: Annual review of marine science Vol. 13; no. 1; pp. 501 - 536
• Main Authors: Nittrouer, Charles A, DeMaster, David J, Kuehl, Steven A, Figueiredo, Alberto G, Sternberg, Richard W, Faria, L. Ercilio C, Silveira, Odete M, Allison, Mead A, Kineke, Gail C, Ogston, Andrea S, Souza Filho, Pedro W.M, Asp, Nils E, Nowacki, Daniel J, Fricke, Aaron T
• Format: Journal Article
• Language: English
• Published: United States Annual Reviews 03-01-2021; Annual Reviews, Inc
• Subjects: Accumulation; Amazon River; Brackishwater environment; continental shelf; Continental shelves; Environmental conditions; Environmental Monitoring - methods; Estuaries; Floodplains; Fresh water; Freshwater; Geologic Sediments - chemistry; Human influences; Humans; Inland water environment; mangrove shoreline; Mangrove swamps; Mangroves; Oceans and Seas; Perturbation; River mouth; River mouths; Rivers; Rivers - chemistry; Sediment; sediment accumulation; Sediment transport; South America; Tidal flats; tidal river; Tidal rivers; Tidal waterways; Tidal Waves; Tributaries; Water discharge; Water Movements; Wetlands; South America; continental shelf; sediment transport; Amazon River; sediment accumulation; mangrove shoreline; tidal river
• ISSN: 1941-1405; 1941-0611
• DOI: 10.1146/annurev-marine-010816-060457

Sediment transfer from land to ocean begins in coastal settings and, for large rivers such as the Amazon, has dramatic impacts over thousands of kilometers covering diverse environmental conditions. In the relatively natural Amazon tidal river, combinations of fluvial and marine processes transition toward the ocean, affecting the transport and accumulation of sediment in floodplains and tributary mouths. The enormous discharge of Amazon fresh water causes estuarine processes to occur on the continental shelf, where much sediment accumulation creates a large clinoform structure and where additional sediment accumulates along its shoreward boundary in tidal flats and mangrove forests. Some remaining Amazon sediment is transported beyond the region near the river mouth, and fluvial forces on it diminish. Numerous perturbations to Amazon sediment transport and accumulation occur naturally, but human actions will likely dominate future change, and now is the time to document, understand, and mitigate their impacts.