Analysis of seafloor depth anomalies between the ascension and St. Helena Islands, South Atlantic
Autor(a) principal: | |
---|---|
Data de Publicação: | 2007 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Revista Brasileira de Geofísica (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X2007000500011 |
Resumo: | Observed seafloor depths from 12 kHz bathymetry coupled with seafloor spreading magnetic anomalies were used to obtain depth anomalies across the Mid-Atlantic ridge axis between 2ºS and 18ºS. The theoretical seafloor depths were calculated from the plate cooling model and crustal ages depicted from seafloor spreading magnetic anomalies between 0 to 25 Ma. We noticed that the seafloor spreading magnetic anomalies are symmetric with respect to the ridge axis between Ascension and St. Helena Islands, but the depth anomalies are quite asymmetric. The east side of the ridge axis is shallower (~ 1,000 meters) than the west side, probably as a result of a thermal upwelling of the lithosphere. We suggest that a mantle plume located on the African Plate, which could represent a larger swell linked to Ascension, St. Helena and Fernando Pó-Annobon Volcanic Lineament, might cause this type of anomaly. |
id |
SBG-3_784e3ffbdb1a140ea7b99298977b033b |
---|---|
oai_identifier_str |
oai:scielo:S0102-261X2007000500011 |
network_acronym_str |
SBG-3 |
network_name_str |
Revista Brasileira de Geofísica (Online) |
repository_id_str |
|
spelling |
Analysis of seafloor depth anomalies between the ascension and St. Helena Islands, South Atlanticdepth anomaliesmagnetic anomaliesAscension IslandSt. Helena IslandSouth AtlanticObserved seafloor depths from 12 kHz bathymetry coupled with seafloor spreading magnetic anomalies were used to obtain depth anomalies across the Mid-Atlantic ridge axis between 2ºS and 18ºS. The theoretical seafloor depths were calculated from the plate cooling model and crustal ages depicted from seafloor spreading magnetic anomalies between 0 to 25 Ma. We noticed that the seafloor spreading magnetic anomalies are symmetric with respect to the ridge axis between Ascension and St. Helena Islands, but the depth anomalies are quite asymmetric. The east side of the ridge axis is shallower (~ 1,000 meters) than the west side, probably as a result of a thermal upwelling of the lithosphere. We suggest that a mantle plume located on the African Plate, which could represent a larger swell linked to Ascension, St. Helena and Fernando Pó-Annobon Volcanic Lineament, might cause this type of anomaly.Sociedade Brasileira de Geofísica2007-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X2007000500011Revista Brasileira de Geofísica v.25 suppl.1 2007reponame:Revista Brasileira de Geofísica (Online)instname:Sociedade Brasileira de Geofísica (SBG)instacron:SBG10.1590/S0102-261X2007000500011info:eu-repo/semantics/openAccessMakler,MarisaMello,Sidney Luiz de Matoseng2007-11-06T00:00:00Zoai:scielo:S0102-261X2007000500011Revistahttp://www.scielo.br/rbgONGhttps://old.scielo.br/oai/scielo-oai.php||sbgf@sbgf.org.br1809-45110102-261Xopendoar:2007-11-06T00:00Revista Brasileira de Geofísica (Online) - Sociedade Brasileira de Geofísica (SBG)false |
dc.title.none.fl_str_mv |
Analysis of seafloor depth anomalies between the ascension and St. Helena Islands, South Atlantic |
title |
Analysis of seafloor depth anomalies between the ascension and St. Helena Islands, South Atlantic |
spellingShingle |
Analysis of seafloor depth anomalies between the ascension and St. Helena Islands, South Atlantic Makler,Marisa depth anomalies magnetic anomalies Ascension Island St. Helena Island South Atlantic |
title_short |
Analysis of seafloor depth anomalies between the ascension and St. Helena Islands, South Atlantic |
title_full |
Analysis of seafloor depth anomalies between the ascension and St. Helena Islands, South Atlantic |
title_fullStr |
Analysis of seafloor depth anomalies between the ascension and St. Helena Islands, South Atlantic |
title_full_unstemmed |
Analysis of seafloor depth anomalies between the ascension and St. Helena Islands, South Atlantic |
title_sort |
Analysis of seafloor depth anomalies between the ascension and St. Helena Islands, South Atlantic |
author |
Makler,Marisa |
author_facet |
Makler,Marisa Mello,Sidney Luiz de Matos |
author_role |
author |
author2 |
Mello,Sidney Luiz de Matos |
author2_role |
author |
dc.contributor.author.fl_str_mv |
Makler,Marisa Mello,Sidney Luiz de Matos |
dc.subject.por.fl_str_mv |
depth anomalies magnetic anomalies Ascension Island St. Helena Island South Atlantic |
topic |
depth anomalies magnetic anomalies Ascension Island St. Helena Island South Atlantic |
description |
Observed seafloor depths from 12 kHz bathymetry coupled with seafloor spreading magnetic anomalies were used to obtain depth anomalies across the Mid-Atlantic ridge axis between 2ºS and 18ºS. The theoretical seafloor depths were calculated from the plate cooling model and crustal ages depicted from seafloor spreading magnetic anomalies between 0 to 25 Ma. We noticed that the seafloor spreading magnetic anomalies are symmetric with respect to the ridge axis between Ascension and St. Helena Islands, but the depth anomalies are quite asymmetric. The east side of the ridge axis is shallower (~ 1,000 meters) than the west side, probably as a result of a thermal upwelling of the lithosphere. We suggest that a mantle plume located on the African Plate, which could represent a larger swell linked to Ascension, St. Helena and Fernando Pó-Annobon Volcanic Lineament, might cause this type of anomaly. |
publishDate |
2007 |
dc.date.none.fl_str_mv |
2007-01-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X2007000500011 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X2007000500011 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0102-261X2007000500011 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Geofísica |
publisher.none.fl_str_mv |
Sociedade Brasileira de Geofísica |
dc.source.none.fl_str_mv |
Revista Brasileira de Geofísica v.25 suppl.1 2007 reponame:Revista Brasileira de Geofísica (Online) instname:Sociedade Brasileira de Geofísica (SBG) instacron:SBG |
instname_str |
Sociedade Brasileira de Geofísica (SBG) |
instacron_str |
SBG |
institution |
SBG |
reponame_str |
Revista Brasileira de Geofísica (Online) |
collection |
Revista Brasileira de Geofísica (Online) |
repository.name.fl_str_mv |
Revista Brasileira de Geofísica (Online) - Sociedade Brasileira de Geofísica (SBG) |
repository.mail.fl_str_mv |
||sbgf@sbgf.org.br |
_version_ |
1754820936855453696 |