Note on the occurrence of saline fronts in the Ilha Grande (RJ) region

Miranda, Luíz Bruner de; Ikeda, Yoshimine; Filho, Belmiro Mendes de Castro; Filho, Nuno Pereira

doi:10.1590/s0373-55241977000200003

Cited by 10 publications

(2 citation statements)

References 5 publications

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“…The ratios 206 Pb/ 207 Pb for the Paraty Bay had shown a variation between 1.180 and 1.202 and can be compared to reported anthropogenic signatures in other studies in Brazil. The isotopic signatures of the Pouso Bay indicate [9]. The comparison of these values with data of the literature of studies in coastal areas in Brazil is shown in Figure 7.…”

Section: Discussionmentioning

confidence: 59%

Pb Isotopes Study in Recent Sediments from Paraty Bay (Rio de Janeiro, Brazil): Antropogenic Versus Oceanic Signatures

Geraldes¹,

Pereira²,

Villena³

et al. 2015

IJG

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We carried out Pb isotopes studies in sediments from Paraty Bay located in the SE area of the Rio de Janeiro State to discriminate the signature of metal contamination from domestic sewage, industries, shipyards and geogenic sources. The studied samples have been chosen in two sectors of the Bay, including the Paraty area and Juatinga Bay. Sample preparation procedures included: 1) drying and granulometric separations (200 mesh); 2) weighting; 3) complete dissolution and 4) Pb isotope analysis obtained by MC-ICP-MS (ratios 208 Pb/ 204 Pb, 207 Pb/ 204 Pb, 206 Pb/ 204 Pb). Preliminary results when plotted in the 207 Pb/ 204 Pb versus 208 Pb/ 204 Pb and 207 Pb/ 206 Pb versus 206 Pb/ 204 Pb diagrams showed three groups of signatures. The first group (samples PY-01, PY-03 PY-106 and PY-127) presented 207 Pb/ 206 Pb values in the range from 1.191 to 1.209. The isotope values may be interpreted as contribution of a pollutant sources of Pb not yet identified. The second group (PY-11, PY-13, PY-21, PY-22, PY-46, PY-51, PY-109 and PY-111) showed 207 Pb/ 206 Pb values in the range from 1.188 to 1.222. The last group (samples PY-123 and PY-135) presented higher 207 Pb/ 206 Pb values from 1.321 to 1.322 and probably represented oceanic signature. The Pb isotope data of the second group may be interpreted as the result of oceanic water and pollutant sources mixture from the continent. According to the literature the anomalous Pb signature is similar to anthropogenic source. The Pb isotope results here reported are coherent with the reported data from the continent area. We may conclude that significant isotopic differences in Pb signatures are consequence of anthropogenic Pb isotope signature. In this way, Pb isotope is an important tool to trace the changing sources of pollutant Pb (and other metals) in ocean environment.

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Section: Discussionmentioning

confidence: 59%

Pb Isotopes Study in Recent Sediments from Paraty Bay (Rio de Janeiro, Brazil): Antropogenic Versus Oceanic Signatures

Geraldes¹,

Pereira²,

Villena³

et al. 2015

IJG

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“…The significance of flows related to various forces has been widely acknowledged in studies, including factors such as local wind friction and density [32][33][34]. However, as noted by Kjerfve et al [35], for the Ilha Grande Channel, wind and ocean dynamics take on a paramount role in local hydrodynamics, accounting for 67% of the annual variation in sea levels.…”

Section: Introductionmentioning

confidence: 99%

Meteorological Signal on Hydrodynamics in the Ilha Grande and Sepetiba Bays: Lag Effects and Coastal Currents

Pereira,

Vinzón,

Gallo

et al. 2024

Hydrology

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On the southeastern coast of Brazil, the bays of Ilha Grande and Sepetiba are linked by the Ilha Grande Channel, where remarkably strong currents have been consistently observed. Tidal forces cannot explain the strength of these currents. Previous researchers have focused on investigating factors like baroclinic effects due to salinity differences or seiches between two basins without a conclusive answer. This study aims to elucidate the role of remote meteorological effects within this complex hydrodynamic system. A numerical approach with a coastal model nested within an ocean model was employed, enabling an in-depth examination of the intricate interplay between meteorological and tidal forcings. The study revealed a significant finding: the lag in signal propagation plays a pivotal role in determining how these signals impact the dynamics of the bays. The astronomical signal exhibits a minimal lag along the coast (1 min) and leads to water level differences between the sea and the coastline, resulting in the generation of tidal currents at the bay entrances. On the other hand, the remote meteorological signal, with a stronger signal lag along the coast (4.92 h), leads to the creation of a water level difference between the bay entrances, inducing significant fluxes along the narrow Ilha Grande Channel.

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Biodiversity and structure of marine sponge assemblages around a subtropical island

et al. 2020

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Note on the occurrence of saline fronts in the Ilha Grande (RJ) region

Cited by 10 publications

References 5 publications

Pb Isotopes Study in Recent Sediments from Paraty Bay (Rio de Janeiro, Brazil): Antropogenic Versus Oceanic Signatures

Pb Isotopes Study in Recent Sediments from Paraty Bay (Rio de Janeiro, Brazil): Antropogenic Versus Oceanic Signatures

Meteorological Signal on Hydrodynamics in the Ilha Grande and Sepetiba Bays: Lag Effects and Coastal Currents

Biodiversity and structure of marine sponge assemblages around a subtropical island

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