Holocene sea-level history along eastern-southeastern Brazil
Autor(a) principal: | |
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Data de Publicação: | 2003 |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Anuário do Instituto de Geociências (Online) |
Texto Completo: | https://revistas.ufrj.br/index.php/aigeo/article/view/6244 |
Resumo: | Relative sea-level curves have been delineated for several sectors of the Brazilian coast. In order to have homogeneous and consistent curves, very short segments of the coastline with the same framework are considered. To minimize systematic errors tied to the particular nature of an indicator, we use the maximum number of different indicators available from former positions of relative sea level. These sea-level curves show that, during the last 7000 years, the central Brazilian coast has been subjected to a submergence phase which lasted until 5100 14C yr BP (5600 cal yr BP), followed by a drop in sea level. This drop in sea level was not continuous but was interrupted by two high-frequency oscillations. The Salvador curve, the most detailed, can be used as a reference for the central portion of the Brazilian coastline. It is now presented with corrections for isotopic fractionation and reservoir effects as well as calibrations for astronomical ages. Additional supporting evidence for the existence of high-frequency oscillations is provided. They are of the same magnitude as is predicted for the future under greenhouse conditions. These data will help us to understand how the coastal systems will respond to these sea-level changes. |
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Holocene sea-level history along eastern-southeastern BrazilHolocene sea-level history along eastern-southeastern BrazilRelative sea-level curves have been delineated for several sectors of the Brazilian coast. In order to have homogeneous and consistent curves, very short segments of the coastline with the same framework are considered. To minimize systematic errors tied to the particular nature of an indicator, we use the maximum number of different indicators available from former positions of relative sea level. These sea-level curves show that, during the last 7000 years, the central Brazilian coast has been subjected to a submergence phase which lasted until 5100 14C yr BP (5600 cal yr BP), followed by a drop in sea level. This drop in sea level was not continuous but was interrupted by two high-frequency oscillations. The Salvador curve, the most detailed, can be used as a reference for the central portion of the Brazilian coastline. It is now presented with corrections for isotopic fractionation and reservoir effects as well as calibrations for astronomical ages. Additional supporting evidence for the existence of high-frequency oscillations is provided. They are of the same magnitude as is predicted for the future under greenhouse conditions. These data will help us to understand how the coastal systems will respond to these sea-level changes.Curvas de variações do nível relativo do mar foram construidas para diversos setores do litoral brasileiro. A fim de obter curvas homogênas, foram utilizados dados provenientes de setores relativamente curtos do litoral com características geológicas uniformes. Para minimizar eventuais erros sistemáticos ligados à própria natureza de um indicador o máximo de indicadores diferentes de antigas posições do nível relativo do mar foi utilizado. Essas curvas mostram que, no decorrer dos últimos 7000 anos, a parte central da costa brasileira foi submetida a uma fase de submersão, até mais ou menos de 5100 14C anos AP (5600 cal anos AP), seguida por uma fase de emersão. Esseabaixamento do nível relativo do mar não foi contínuo mas caracterizado por duas oscilações de alta freqüência. A curva de variação do nível relativo do mar construída no fim dos anos 70 na região de Salvador, que serve de referência para a parte central da costa brasileira, foi reconstruída depois de uma normalização e uma calibração das idades 14C. Por outro lado, informações complementares que convergem fortemente no sentido de sustentar a existência de oscilações rápidas do nível relativo do mar são analisadas. A comprovação da existência de oscilações rápidas do nível relativo do mar (da ordem do metro por seculo) nos últimos milênios constitue um elemento importante na compreensão da evolução futura da zona costeira. Efetivamente, a anlise dos efeitos dessas oscilações sobre a morfologia da zona costeira pode fornecer exemplos do que poderá acontecer em conseqüência de uma eventual elevação do nível do mar com amplitude e velocidade equivalente.Universidade Federal do Rio de JaneiroMartin, Louis2003-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://revistas.ufrj.br/index.php/aigeo/article/view/624410.11137/2003_0_13-24Anuário do Instituto de Geociências; Vol 26 (2003); 13-24Anuário do Instituto de Geociências; Vol 26 (2003); 13-241982-39080101-9759reponame:Anuário do Instituto de Geociências (Online)instname:Universidade Federal do Rio de Janeiro (UFRJ)instacron:UFRJenghttps://revistas.ufrj.br/index.php/aigeo/article/view/6244/4841Copyright (c) 2003 Anuário do Instituto de Geociênciashttp://creativecommons.org/licenses/by/4.0info:eu-repo/semantics/openAccess2021-08-20T08:21:14Zoai:www.revistas.ufrj.br:article/6244Revistahttps://revistas.ufrj.br/index.php/aigeo/indexPUBhttps://revistas.ufrj.br/index.php/aigeo/oaianuario@igeo.ufrj.br||1982-39080101-9759opendoar:2021-08-20T08:21:14Anuário do Instituto de Geociências (Online) - Universidade Federal do Rio de Janeiro (UFRJ)false |
dc.title.none.fl_str_mv |
Holocene sea-level history along eastern-southeastern Brazil Holocene sea-level history along eastern-southeastern Brazil |
title |
Holocene sea-level history along eastern-southeastern Brazil |
spellingShingle |
Holocene sea-level history along eastern-southeastern Brazil Martin, Louis |
title_short |
Holocene sea-level history along eastern-southeastern Brazil |
title_full |
Holocene sea-level history along eastern-southeastern Brazil |
title_fullStr |
Holocene sea-level history along eastern-southeastern Brazil |
title_full_unstemmed |
Holocene sea-level history along eastern-southeastern Brazil |
title_sort |
Holocene sea-level history along eastern-southeastern Brazil |
author |
Martin, Louis |
author_facet |
Martin, Louis |
author_role |
author |
dc.contributor.none.fl_str_mv |
|
dc.contributor.author.fl_str_mv |
Martin, Louis |
dc.subject.none.fl_str_mv |
|
description |
Relative sea-level curves have been delineated for several sectors of the Brazilian coast. In order to have homogeneous and consistent curves, very short segments of the coastline with the same framework are considered. To minimize systematic errors tied to the particular nature of an indicator, we use the maximum number of different indicators available from former positions of relative sea level. These sea-level curves show that, during the last 7000 years, the central Brazilian coast has been subjected to a submergence phase which lasted until 5100 14C yr BP (5600 cal yr BP), followed by a drop in sea level. This drop in sea level was not continuous but was interrupted by two high-frequency oscillations. The Salvador curve, the most detailed, can be used as a reference for the central portion of the Brazilian coastline. It is now presented with corrections for isotopic fractionation and reservoir effects as well as calibrations for astronomical ages. Additional supporting evidence for the existence of high-frequency oscillations is provided. They are of the same magnitude as is predicted for the future under greenhouse conditions. These data will help us to understand how the coastal systems will respond to these sea-level changes. |
publishDate |
2003 |
dc.date.none.fl_str_mv |
2003-01-01 |
dc.type.none.fl_str_mv |
|
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://revistas.ufrj.br/index.php/aigeo/article/view/6244 10.11137/2003_0_13-24 |
url |
https://revistas.ufrj.br/index.php/aigeo/article/view/6244 |
identifier_str_mv |
10.11137/2003_0_13-24 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
https://revistas.ufrj.br/index.php/aigeo/article/view/6244/4841 |
dc.rights.driver.fl_str_mv |
Copyright (c) 2003 Anuário do Instituto de Geociências http://creativecommons.org/licenses/by/4.0 info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Copyright (c) 2003 Anuário do Instituto de Geociências http://creativecommons.org/licenses/by/4.0 |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal do Rio de Janeiro |
publisher.none.fl_str_mv |
Universidade Federal do Rio de Janeiro |
dc.source.none.fl_str_mv |
Anuário do Instituto de Geociências; Vol 26 (2003); 13-24 Anuário do Instituto de Geociências; Vol 26 (2003); 13-24 1982-3908 0101-9759 reponame:Anuário do Instituto de Geociências (Online) instname:Universidade Federal do Rio de Janeiro (UFRJ) instacron:UFRJ |
instname_str |
Universidade Federal do Rio de Janeiro (UFRJ) |
instacron_str |
UFRJ |
institution |
UFRJ |
reponame_str |
Anuário do Instituto de Geociências (Online) |
collection |
Anuário do Instituto de Geociências (Online) |
repository.name.fl_str_mv |
Anuário do Instituto de Geociências (Online) - Universidade Federal do Rio de Janeiro (UFRJ) |
repository.mail.fl_str_mv |
anuario@igeo.ufrj.br|| |
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1797053544398848000 |