Hydrodynamic controls on the distribution of surface sediments from the southeast South American continental shelf between 23°S and 38°S

Nagai, Renata Hanae; Ferreira, Paulo Martins; Mulkherjee, Swapna; Martins, Maria Virgínia Alves; Figueira, Rubens César Lopes; Sousa, Silvia Helena de Mello e; Mahiques, Michel Michaelovitch de

doi:10.1016/j.csr.2013.09.016

Cited by 64 publications

(44 citation statements)

References 31 publications

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“…Additionally, the chemical signatures of rivers, aeolian dust, and topsoil samples have been analyzed to estimate the potential riverborne and windborne inputs to the Patagonian littoral (Gaiero et al, 2004(Gaiero et al, , 2007. However, most of the coastal studies, as well as the sampling campaigns, have been conducted in the northern region of the ACS and especially in the Río de La Plata estuary at ~35°S (e.g., Nagai et al, 2014). This focus leads to a disproportionate amount of information available for the north compared to the other coastal and inner shelf areas of Argentina.…”

Section: Introductionmentioning

confidence: 99%

Quantifying Sources and Transport Pathways of Surface Sediments in the Gulf of San Jorge, Central Patagonia (Argentina)

Desiage¹,

Montero‐Serrano²,

St‐Onge³

et al. 2018

Oceanog

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Section: Introductionmentioning

confidence: 99%

Quantifying Sources and Transport Pathways of Surface Sediments in the Gulf of San Jorge, Central Patagonia (Argentina)

Desiage¹,

Montero‐Serrano²,

St‐Onge³

et al. 2018

Oceanog

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“…The Río de la Plata (RdlP) estuary is fed by the Paraná and the Uruguay rivers and drains into the southwestern Atlantic Ocean (SWAO), forming the second largest estuary system in South America (Bisbal, 1995;Acha et al, 2003). The RdlP is the main source of continental freshwater and sediments entering the SWAO Krastel et al, 2011Krastel et al, , 2012Razik et al, 2013;Lantzsch et al, 2014;Nagai et al, 2014). In this sense, the RdlP provides an average annual suspended sediment load of 79.8 × 10 6 t yr −1 (Depetris et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

“…The SAMS is known to be a poleward displacement of the Intertropical Convergence Zone (ITCZ), and it is associated with a wet season that begins in the equatorial Amazon and propagates rapidly eastward and southeastward during austral spring (García and Kayano, 2010). The SAMS is closely associated with the South Atlantic Convergence Zone (SACZ; Carvalho et al, 2004), which is a main component of the SAMS (Nogués-Paegle et al, 2002;Almeida et al, 2007). The SACZ is an elongated NW-SE band of convective activity that originates in the Amazon Basin, which extends above the northern RdlP drainage basin, and has its southernmost limit in the adjacent SWAO (Carvalho et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Variability in terrigenous sediment supply offshore of the Río de la Plata (Uruguay) recording the continental climatic history over the past 1200 years

2016

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Abstract. The continental shelf adjacent to the Río de la Plata (RdlP) exhibits extremely complex hydrographic and ecological characteristics which are of great socioeconomic importance. Since the long-term environmental variations related to the atmospheric (wind fields), hydrologic (freshwater plume), and oceanographic (currents and fronts) regimes are little known, the aim of this study is to reconstruct the changes in the terrigenous input into the inner continental shelf during the late Holocene period (associated with the RdlP sediment discharge) and to unravel the climatic forcing mechanisms behind them. To achieve this, we retrieved a 10 m long sediment core from the RdlP mud depocenter at 57 m water depth (GeoB 13813-4). The radiocarbon age control indicated an extremely high sedimentation rate of 0.8 cm per year, encompassing the past 1200 years (AD 750–2000). We used element ratios (Ti  / Ca, Fe / Ca, Ti / Al, Fe / K) as regional proxies for the fluvial input signal and the variations in relative abundance of salinity-indicative diatom groups (freshwater versus marine-brackish) to assess the variability in terrigenous freshwater and sediment discharges. Ti / Ca, Fe / Ca, Ti /  Al, Fe /  K and the freshwater diatom group showed the lowest values between AD 850 and 1300, while the highest values occurred between AD 1300 and 1850. The variations in the sedimentary record can be attributed to the Medieval Climatic Anomaly (MCA) and the Little Ice Age (LIA), both of which had a significant impact on rainfall and wind patterns over the region. During the MCA, a weakening of the South American summer monsoon system (SAMS) and the South Atlantic Convergence Zone (SACZ), could explain the lowest element ratios (indicative of a lower terrigenous input) and a marine-dominated diatom record, both indicative of a reduced RdlP freshwater plume. In contrast, during the LIA, a strengthening of SAMS and SACZ may have led to an expansion of the RdlP river plume to the far north, as indicated by higher element ratios and a marked freshwater diatom signal. Furthermore, a possible multidecadal oscillation probably associated with Atlantic Multidecadal Oscillation (AMO) since AD 1300 reflects the variability in both the SAMS and SACZ systems.

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“…Beyond the oceanographic differences off northern and southern São Sebastião Island (MIRANDA; , larval fish assemblages also differ when analyzing these two subareas (KATSURAGAWA et al, 2014). It is also important to note that the mineralogy of the surface sediments between Cape Frio (23°S) and the mouth of the Plata River (38°S) is controlled by two oceanographic conditions: the Brazil Current (BC), supplying the shelf with clay minerals from equatorial regions, and the Brazil Coastal Current (BCC), transporting sediments from the Plata River (NAGAI et al, 2014). This sediment distribution shows that area between Itajaí (27°S) and São Sebastião Island (24°S) can be considered as a transitional zone between the dominance of the BC and the BCC (NAGAI et al, 2014).…”

Section: Iv4 Discussionmentioning

confidence: 99%

<i>Engraulis anchoita</i> (Clupeiformes: Engraulidae) eggs and larvae in the Southeastern Brazilian Bight: new perspectives from a historical data set (1974 - 2010)

Favero¹

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First of all I would like to thank both of my advisors, Prof. Mario Katsuragawa (IOUSP) and Prof. Jefferson T. Turner (SMAST-UMASS), for all of the support offered throughout these years. You both were so kind for sharing your knowledge with me, patient with all of my corrections, and very helpful in dealing with the bureaucracies involved in the double degree program. I would like also to thank my "third" advisor, the IOUSP technician Maria de Lourdes Zani-Teixeira, who sometimes was a second mother, helping not just with the research, but also with personal problems. I am extremely thankful to FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo), for funding my research project in Brazil (n° 2011/23332-3) and in the USA (n° 2014/00365-1). I thank the professors from USP and UMASS, for the great lectures, courses, and conversations, especially Prof. June Ferraz Dias (IOUSP), for being more than a professor, but also a friend, always ready to answer any question (professional or not!). Special thanks also to Prof. Ilson Carlos Almeida da Silveira (IOUSP) and Prof. Avijit Gangopadhyay (SMAST), for making the dual degree program possible and for helping me every time I had a problem or a doubt. It is impossible to cite all of the names here, but I thank all IOUSP and SMAST staff. The absence of your help would have made my work much harder.

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Hydrodynamic controls on the distribution of surface sediments from the southeast South American continental shelf between 23°S and 38°S

Cited by 64 publications

References 31 publications

Quantifying Sources and Transport Pathways of Surface Sediments in the Gulf of San Jorge, Central Patagonia (Argentina)

Quantifying Sources and Transport Pathways of Surface Sediments in the Gulf of San Jorge, Central Patagonia (Argentina)

Variability in terrigenous sediment supply offshore of the Río de la Plata (Uruguay) recording the continental climatic history over the past 1200 years

<i>Engraulis anchoita</i> (Clupeiformes: Engraulidae) eggs and larvae in the Southeastern Brazilian Bight: new perspectives from a historical data set (1974 - 2010)

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