Observations of ridge-hotspot interactions in the Southern Ocean
The evolution of ridge-hotspot systems is not well understood. In this investigation, satellite-derived marine gravity data are used in conjunction with underway bathymetric and magnetic anomaly profiles to investigate the nature of ridge-hotspot interaction at four sparsely explored systems in the...
Published in: | Journal of Geophysical Research: Solid Earth |
---|---|
Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
AGU (American Geophysical Union)
2012
|
Subjects: | |
Online Access: | https://oceanrep.geomar.de/id/eprint/32811/ https://oceanrep.geomar.de/id/eprint/32811/1/Small.pdf https://doi.org/10.1029/95JB01377 |
id |
ftoceanrep:oai:oceanrep.geomar.de:32811 |
---|---|
record_format |
openpolar |
spelling |
ftoceanrep:oai:oceanrep.geomar.de:32811 2023-05-15T13:57:04+02:00 Observations of ridge-hotspot interactions in the Southern Ocean Small, Christopher 2012 text https://oceanrep.geomar.de/id/eprint/32811/ https://oceanrep.geomar.de/id/eprint/32811/1/Small.pdf https://doi.org/10.1029/95JB01377 en eng AGU (American Geophysical Union) https://oceanrep.geomar.de/id/eprint/32811/1/Small.pdf Small, C. (2012) Observations of ridge-hotspot interactions in the Southern Ocean. Journal of Geophysical Research - Solid Earth, 100 (B9). pp. 17931-17946. DOI 10.1029/95JB01377 <https://doi.org/10.1029/95JB01377>. doi:10.1029/95JB01377 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2012 ftoceanrep https://doi.org/10.1029/95JB01377 2023-04-07T15:25:24Z The evolution of ridge-hotspot systems is not well understood. In this investigation, satellite-derived marine gravity data are used in conjunction with underway bathymetric and magnetic anomaly profiles to investigate the nature of ridge-hotspot interaction at four sparsely explored systems in the Southern Ocean. These systems illustrate three different stages of ridge-hotspot interaction in which a migrating spreading center approaches a hotspot (Pacific-Antarctic/Louisville), passes over or is captured by the hotspot (Mid-Atlantic/Shona-Discovery), and ultimately migrates away from the hotspot (Southeast Indian/Kerguelen). All of these systems show some evidence of discrete ridge jumps in the direction of the hotspot as the spreading center attempts to relocate toward the hotspot by asymmetric spreading. Interestingly, these ridge jumps show no evidence of propagating offsets as have been seen on many other ridge-hotspot systems. A simple model predicts that typical plume excess temperatures can weaken the lithosphere sufficiently to promote asymmetric spreading and possibly allow a discrete ridge jump. The presence of previously uncharted, obliquely oriented aseismic ridges and gravity lineations between the ridge and the hotspot supports the notion of asthenospheric flux from the plume to the spreading center both before and after the time when the hotspot is ridge centered. The azimuths of the aseismic ridges cannot be explained by plate kinematics alone; they consistently extend from the ends toward the centers of the adjacent spreading segments suggesting some interaction between plume derived asthenospheric flux and local lithospheric structure. The features discussed here also indicate that the transfer of asthenospheric material from the plume to the spreading center is influenced by the local plate boundary configuration and interaction with transform offsets. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Indian Kerguelen Pacific Southern Ocean Journal of Geophysical Research: Solid Earth 100 B9 17931 17946 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
The evolution of ridge-hotspot systems is not well understood. In this investigation, satellite-derived marine gravity data are used in conjunction with underway bathymetric and magnetic anomaly profiles to investigate the nature of ridge-hotspot interaction at four sparsely explored systems in the Southern Ocean. These systems illustrate three different stages of ridge-hotspot interaction in which a migrating spreading center approaches a hotspot (Pacific-Antarctic/Louisville), passes over or is captured by the hotspot (Mid-Atlantic/Shona-Discovery), and ultimately migrates away from the hotspot (Southeast Indian/Kerguelen). All of these systems show some evidence of discrete ridge jumps in the direction of the hotspot as the spreading center attempts to relocate toward the hotspot by asymmetric spreading. Interestingly, these ridge jumps show no evidence of propagating offsets as have been seen on many other ridge-hotspot systems. A simple model predicts that typical plume excess temperatures can weaken the lithosphere sufficiently to promote asymmetric spreading and possibly allow a discrete ridge jump. The presence of previously uncharted, obliquely oriented aseismic ridges and gravity lineations between the ridge and the hotspot supports the notion of asthenospheric flux from the plume to the spreading center both before and after the time when the hotspot is ridge centered. The azimuths of the aseismic ridges cannot be explained by plate kinematics alone; they consistently extend from the ends toward the centers of the adjacent spreading segments suggesting some interaction between plume derived asthenospheric flux and local lithospheric structure. The features discussed here also indicate that the transfer of asthenospheric material from the plume to the spreading center is influenced by the local plate boundary configuration and interaction with transform offsets. |
format |
Article in Journal/Newspaper |
author |
Small, Christopher |
spellingShingle |
Small, Christopher Observations of ridge-hotspot interactions in the Southern Ocean |
author_facet |
Small, Christopher |
author_sort |
Small, Christopher |
title |
Observations of ridge-hotspot interactions in the Southern Ocean |
title_short |
Observations of ridge-hotspot interactions in the Southern Ocean |
title_full |
Observations of ridge-hotspot interactions in the Southern Ocean |
title_fullStr |
Observations of ridge-hotspot interactions in the Southern Ocean |
title_full_unstemmed |
Observations of ridge-hotspot interactions in the Southern Ocean |
title_sort |
observations of ridge-hotspot interactions in the southern ocean |
publisher |
AGU (American Geophysical Union) |
publishDate |
2012 |
url |
https://oceanrep.geomar.de/id/eprint/32811/ https://oceanrep.geomar.de/id/eprint/32811/1/Small.pdf https://doi.org/10.1029/95JB01377 |
geographic |
Antarctic Indian Kerguelen Pacific Southern Ocean |
geographic_facet |
Antarctic Indian Kerguelen Pacific Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
https://oceanrep.geomar.de/id/eprint/32811/1/Small.pdf Small, C. (2012) Observations of ridge-hotspot interactions in the Southern Ocean. Journal of Geophysical Research - Solid Earth, 100 (B9). pp. 17931-17946. DOI 10.1029/95JB01377 <https://doi.org/10.1029/95JB01377>. doi:10.1029/95JB01377 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1029/95JB01377 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
100 |
container_issue |
B9 |
container_start_page |
17931 |
op_container_end_page |
17946 |
_version_ |
1766264668874080256 |