The relationship between depth, age and gravity in the oceans
We reassess the applicability of the thermal plate cooling model to the subsidence of the North Pacific, Atlantic and North Indian Ocean Basins. We use a new numerical plate model in which the thermophysical parameters of the lithosphere vary with temperature according to the results of laboratory e...
Published in: | Geophysical Journal International |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Royal Astronomical Society
2006
|
Subjects: | |
Online Access: | http://eprints.esc.cam.ac.uk/226/ http://eprints.esc.cam.ac.uk/226/1/Crosby_McKenzie_GJI_166_2006.PDF http://eprints.esc.cam.ac.uk/226/6/GJI_3015_f1.gif |
id |
ftucambridgeesc:oai:eprints.esc.cam.ac.uk:226 |
---|---|
record_format |
openpolar |
spelling |
ftucambridgeesc:oai:eprints.esc.cam.ac.uk:226 2023-05-15T17:41:40+02:00 The relationship between depth, age and gravity in the oceans Crosby, A. McKenzie, D. P. Sclater, J. G. 2006-08 text image http://eprints.esc.cam.ac.uk/226/ http://eprints.esc.cam.ac.uk/226/1/Crosby_McKenzie_GJI_166_2006.PDF http://eprints.esc.cam.ac.uk/226/6/GJI_3015_f1.gif en eng Royal Astronomical Society http://eprints.esc.cam.ac.uk/226/1/Crosby_McKenzie_GJI_166_2006.PDF http://eprints.esc.cam.ac.uk/226/6/GJI_3015_f1.gif Crosby, A. and McKenzie, D. P. and Sclater, J. G. (2006) The relationship between depth, age and gravity in the oceans. Geophysical Journal International, 166 (2). pp. 553-573. ISSN ISSN: 0956-540X, ESSN: 1365-246X DOI https://doi.org/10.1111/j.1365-246X.2006.03015.x <https://doi.org/10.1111/j.1365-246X.2006.03015.x> 02 - Geodynamics Geophysics and Tectonics Article PeerReviewed 2006 ftucambridgeesc https://doi.org/10.1111/j.1365-246X.2006.03015.x 2020-08-27T18:08:27Z We reassess the applicability of the thermal plate cooling model to the subsidence of the North Pacific, Atlantic and North Indian Ocean Basins. We use a new numerical plate model in which the thermophysical parameters of the lithosphere vary with temperature according to the results of laboratory experiments, and the ridge temperature structure is consistent with the thickness of the oceanic crust. We first attempt to exclude thickened crust from our data set, and then to exclude swells and downwellings by masking regions of the data that remains that have significant gravity anomalies when there exists a clear regional correlation between intermediate-wavelength gravity and topography. We find that the average variation of depth with age is consistent with conventional half-space models until about 90 Myr. Thereafter, the departure from the half-space cooling curve is more rapid than predicted using simple conductive plate cooling models. The depth–age curves in the Pacific and Atlantic show ∼250 m of temporary shallowing between the ages of 90–130 Myr, a result consistent with the outcome of experiments on the initiation of small-scale boundary layer convection. The results do not change significantly if the estimated component of the gravity arising from plate cooling is subtracted prior to calculation of the correlation between gravity and topography. A 90-km-thick conductive plate is nevertheless a reasonable model for the average temperature structure of the oldest part of the Pacific ocean lithosphere. In the Pacific, the broad topographic undulations associated with the Line Island Swell, the Hawaiian Swell and surrounding basins have correlated gravity anomalies and an admittance of approximately 30 mGal km−1 and are likely to result from convective circulation in the upper mantle. In the Northeast Atlantic, the intermediate-wavelength admittance over the Cape Verde swell is similar; in the Northwest Atlantic over the Bermuda Swell it is slightly larger but not as well constrained. Article in Journal/Newspaper Northeast Atlantic Northwest Atlantic University of Cambridge, Department of Earth Sciences: ESC Publications Pacific Indian Geophysical Journal International 166 2 553 573 |
institution |
Open Polar |
collection |
University of Cambridge, Department of Earth Sciences: ESC Publications |
op_collection_id |
ftucambridgeesc |
language |
English |
topic |
02 - Geodynamics Geophysics and Tectonics |
spellingShingle |
02 - Geodynamics Geophysics and Tectonics Crosby, A. McKenzie, D. P. Sclater, J. G. The relationship between depth, age and gravity in the oceans |
topic_facet |
02 - Geodynamics Geophysics and Tectonics |
description |
We reassess the applicability of the thermal plate cooling model to the subsidence of the North Pacific, Atlantic and North Indian Ocean Basins. We use a new numerical plate model in which the thermophysical parameters of the lithosphere vary with temperature according to the results of laboratory experiments, and the ridge temperature structure is consistent with the thickness of the oceanic crust. We first attempt to exclude thickened crust from our data set, and then to exclude swells and downwellings by masking regions of the data that remains that have significant gravity anomalies when there exists a clear regional correlation between intermediate-wavelength gravity and topography. We find that the average variation of depth with age is consistent with conventional half-space models until about 90 Myr. Thereafter, the departure from the half-space cooling curve is more rapid than predicted using simple conductive plate cooling models. The depth–age curves in the Pacific and Atlantic show ∼250 m of temporary shallowing between the ages of 90–130 Myr, a result consistent with the outcome of experiments on the initiation of small-scale boundary layer convection. The results do not change significantly if the estimated component of the gravity arising from plate cooling is subtracted prior to calculation of the correlation between gravity and topography. A 90-km-thick conductive plate is nevertheless a reasonable model for the average temperature structure of the oldest part of the Pacific ocean lithosphere. In the Pacific, the broad topographic undulations associated with the Line Island Swell, the Hawaiian Swell and surrounding basins have correlated gravity anomalies and an admittance of approximately 30 mGal km−1 and are likely to result from convective circulation in the upper mantle. In the Northeast Atlantic, the intermediate-wavelength admittance over the Cape Verde swell is similar; in the Northwest Atlantic over the Bermuda Swell it is slightly larger but not as well constrained. |
format |
Article in Journal/Newspaper |
author |
Crosby, A. McKenzie, D. P. Sclater, J. G. |
author_facet |
Crosby, A. McKenzie, D. P. Sclater, J. G. |
author_sort |
Crosby, A. |
title |
The relationship between depth, age and gravity in the oceans |
title_short |
The relationship between depth, age and gravity in the oceans |
title_full |
The relationship between depth, age and gravity in the oceans |
title_fullStr |
The relationship between depth, age and gravity in the oceans |
title_full_unstemmed |
The relationship between depth, age and gravity in the oceans |
title_sort |
relationship between depth, age and gravity in the oceans |
publisher |
Royal Astronomical Society |
publishDate |
2006 |
url |
http://eprints.esc.cam.ac.uk/226/ http://eprints.esc.cam.ac.uk/226/1/Crosby_McKenzie_GJI_166_2006.PDF http://eprints.esc.cam.ac.uk/226/6/GJI_3015_f1.gif |
geographic |
Pacific Indian |
geographic_facet |
Pacific Indian |
genre |
Northeast Atlantic Northwest Atlantic |
genre_facet |
Northeast Atlantic Northwest Atlantic |
op_relation |
http://eprints.esc.cam.ac.uk/226/1/Crosby_McKenzie_GJI_166_2006.PDF http://eprints.esc.cam.ac.uk/226/6/GJI_3015_f1.gif Crosby, A. and McKenzie, D. P. and Sclater, J. G. (2006) The relationship between depth, age and gravity in the oceans. Geophysical Journal International, 166 (2). pp. 553-573. ISSN ISSN: 0956-540X, ESSN: 1365-246X DOI https://doi.org/10.1111/j.1365-246X.2006.03015.x <https://doi.org/10.1111/j.1365-246X.2006.03015.x> |
op_doi |
https://doi.org/10.1111/j.1365-246X.2006.03015.x |
container_title |
Geophysical Journal International |
container_volume |
166 |
container_issue |
2 |
container_start_page |
553 |
op_container_end_page |
573 |
_version_ |
1766143354482982912 |