Linear inversion of a negative gravity anomaly in se Rio Grande cone: a graben on oceanic crust?
We detect, for the first time, a negative free-air gravity anomaly of 23 mGal amplitude over a region in the South Atlantic Ocean centered at 48ºW and 35ºS. To this end, we used the integration of conventional shipborne gravity data and gravity data derived from GEOSAT/ERM satellite altimetry. The n...
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Sociedade Brasileira de Geofísica
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ftjscielo:oai:scielo:S0102-261X2006000300010 2023-05-15T18:21:08+02:00 Linear inversion of a negative gravity anomaly in se Rio Grande cone: a graben on oceanic crust? Leite,Emilson Pereira Ussami,Naomi 2006-09-01 text/html http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X2006000300010 en eng Sociedade Brasileira de Geofísica Revista Brasileira de Geofísica v.24 n.3 2006 Potential Methods Gravity Inversion Rio Grande Cone Oceanic Crust journal article 2006 ftjscielo 2015-10-26T19:37:36Z We detect, for the first time, a negative free-air gravity anomaly of 23 mGal amplitude over a region in the South Atlantic Ocean centered at 48ºW and 35ºS. To this end, we used the integration of conventional shipborne gravity data and gravity data derived from GEOSAT/ERM satellite altimetry. The north bound of this anomaly coincides with the Chuí Lineament and the south bound indicates another lineament, which is the extension of the Meteor Fracture Zone. The anomaly trend is NE-SW, its width is 400 km and its length is 600 km. Two-dimensional linear inversion with relative and absolute equality constraints was used to calculate the density distribution along three profiles perpendicular to the main axis of the anomaly. The result suggests that the sediment thickness in the deepest part of the basin is at least 3.0 km where the ocean bathymetry is 4,800 m. This tectonic feature, an asymmetric half-graben formed between two lineaments, probably lies over an oceanic crust. The estimated volume of sediments in this basin is approximately 50% of the post-Miocene sediments volume deposited in the Rio Grande Cone where gas-hydrates were found. Article in Journal/Newspaper South Atlantic Ocean SciELO Brazil (Scientific Electronic Library Online) |
institution |
Open Polar |
collection |
SciELO Brazil (Scientific Electronic Library Online) |
op_collection_id |
ftjscielo |
language |
English |
topic |
Potential Methods Gravity Inversion Rio Grande Cone Oceanic Crust |
spellingShingle |
Potential Methods Gravity Inversion Rio Grande Cone Oceanic Crust Leite,Emilson Pereira Ussami,Naomi Linear inversion of a negative gravity anomaly in se Rio Grande cone: a graben on oceanic crust? |
topic_facet |
Potential Methods Gravity Inversion Rio Grande Cone Oceanic Crust |
description |
We detect, for the first time, a negative free-air gravity anomaly of 23 mGal amplitude over a region in the South Atlantic Ocean centered at 48ºW and 35ºS. To this end, we used the integration of conventional shipborne gravity data and gravity data derived from GEOSAT/ERM satellite altimetry. The north bound of this anomaly coincides with the Chuí Lineament and the south bound indicates another lineament, which is the extension of the Meteor Fracture Zone. The anomaly trend is NE-SW, its width is 400 km and its length is 600 km. Two-dimensional linear inversion with relative and absolute equality constraints was used to calculate the density distribution along three profiles perpendicular to the main axis of the anomaly. The result suggests that the sediment thickness in the deepest part of the basin is at least 3.0 km where the ocean bathymetry is 4,800 m. This tectonic feature, an asymmetric half-graben formed between two lineaments, probably lies over an oceanic crust. The estimated volume of sediments in this basin is approximately 50% of the post-Miocene sediments volume deposited in the Rio Grande Cone where gas-hydrates were found. |
format |
Article in Journal/Newspaper |
author |
Leite,Emilson Pereira Ussami,Naomi |
author_facet |
Leite,Emilson Pereira Ussami,Naomi |
author_sort |
Leite,Emilson Pereira |
title |
Linear inversion of a negative gravity anomaly in se Rio Grande cone: a graben on oceanic crust? |
title_short |
Linear inversion of a negative gravity anomaly in se Rio Grande cone: a graben on oceanic crust? |
title_full |
Linear inversion of a negative gravity anomaly in se Rio Grande cone: a graben on oceanic crust? |
title_fullStr |
Linear inversion of a negative gravity anomaly in se Rio Grande cone: a graben on oceanic crust? |
title_full_unstemmed |
Linear inversion of a negative gravity anomaly in se Rio Grande cone: a graben on oceanic crust? |
title_sort |
linear inversion of a negative gravity anomaly in se rio grande cone: a graben on oceanic crust? |
publisher |
Sociedade Brasileira de Geofísica |
publishDate |
2006 |
url |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X2006000300010 |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
Revista Brasileira de Geofísica v.24 n.3 2006 |
_version_ |
1766200241239883776 |