A Magma Accretion Model for the Formation of Oceanic Lithosphere: Implications for Global Heat Loss
A magma accretion model of oceanic lithosphere is proposed and its implications for understanding its thermal field examined. The new model (designated Variable Basal Accretion—VBA) assumes existence of lateral variations in magma accretion rates and temperatures at the boundary zone between the lit...
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| Format: | Article |
| Language: | English |
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Wiley
2010-01-01
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| Series: | International Journal of Geophysics |
| Online Access: | http://dx.doi.org/10.1155/2010/146496 |
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| author | Valiya M. Hamza Roberto R. Cardoso Carlos H. Alexandrino |
| author_facet | Valiya M. Hamza Roberto R. Cardoso Carlos H. Alexandrino |
| author_sort | Valiya M. Hamza |
| collection | DOAJ |
| description | A magma accretion model of oceanic lithosphere is proposed and its implications for understanding its thermal field examined. The new model (designated Variable Basal Accretion—VBA) assumes existence of lateral variations in magma accretion rates and temperatures at the boundary zone between the lithosphere and the asthenosphere. However, unlike the previous thermal models of the lithosphere, the ratio of advection to conduction heat transfer is considered a space dependent variable. The results of VBA model simulations reveal that the thickness of the young lithosphere increases with distance from the ridge axis, at rates faster than those predicted by Half-Space Cooling models. Another noteworthy feature of the new model is its ability to account for the main features in the thermal behavior of oceanic lithosphere. The improved fits to bathymetry have been achieved for the entire age range and without the need to invoke the ad-hoc hypothesis of large-scale hydrothermal circulation. Also, use of VBA model does not lead to artificial discontinuities in the temperature field of the lithosphere, as is the case with GDH (Global Depth Heat Flow) reference models. The results suggest that estimates of global heat loss need to be downsized by at least 25%. |
| format | Article |
| id | doaj-art-5845bf2df7e64f49bce4d3ad7e32fb18 |
| institution | Kabale University |
| issn | 1687-885X 1687-8868 |
| language | English |
| publishDate | 2010-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | International Journal of Geophysics |
| spelling | doaj-art-5845bf2df7e64f49bce4d3ad7e32fb182025-08-20T03:33:38ZengWileyInternational Journal of Geophysics1687-885X1687-88682010-01-01201010.1155/2010/146496146496A Magma Accretion Model for the Formation of Oceanic Lithosphere: Implications for Global Heat LossValiya M. Hamza0Roberto R. Cardoso1Carlos H. Alexandrino2Coordenadoria de Geofísica, Observatório Nacional—MCT, Rua General José Cristino, CEP 20921-400, Rio de Janeiro, BrazilCoordenadoria de Geofísica, Observatório Nacional—MCT, Rua General José Cristino, CEP 20921-400, Rio de Janeiro, BrazilInstituto de Ciência e Tecnologia do Mucuri, Universidade Federal dos Vales do Jequitinhonha e Mucuri, CEP 39800-000, Teófilo Otoni, BrazilA magma accretion model of oceanic lithosphere is proposed and its implications for understanding its thermal field examined. The new model (designated Variable Basal Accretion—VBA) assumes existence of lateral variations in magma accretion rates and temperatures at the boundary zone between the lithosphere and the asthenosphere. However, unlike the previous thermal models of the lithosphere, the ratio of advection to conduction heat transfer is considered a space dependent variable. The results of VBA model simulations reveal that the thickness of the young lithosphere increases with distance from the ridge axis, at rates faster than those predicted by Half-Space Cooling models. Another noteworthy feature of the new model is its ability to account for the main features in the thermal behavior of oceanic lithosphere. The improved fits to bathymetry have been achieved for the entire age range and without the need to invoke the ad-hoc hypothesis of large-scale hydrothermal circulation. Also, use of VBA model does not lead to artificial discontinuities in the temperature field of the lithosphere, as is the case with GDH (Global Depth Heat Flow) reference models. The results suggest that estimates of global heat loss need to be downsized by at least 25%.http://dx.doi.org/10.1155/2010/146496 |
| spellingShingle | Valiya M. Hamza Roberto R. Cardoso Carlos H. Alexandrino A Magma Accretion Model for the Formation of Oceanic Lithosphere: Implications for Global Heat Loss International Journal of Geophysics |
| title | A Magma Accretion Model for the Formation of Oceanic Lithosphere: Implications for Global Heat Loss |
| title_full | A Magma Accretion Model for the Formation of Oceanic Lithosphere: Implications for Global Heat Loss |
| title_fullStr | A Magma Accretion Model for the Formation of Oceanic Lithosphere: Implications for Global Heat Loss |
| title_full_unstemmed | A Magma Accretion Model for the Formation of Oceanic Lithosphere: Implications for Global Heat Loss |
| title_short | A Magma Accretion Model for the Formation of Oceanic Lithosphere: Implications for Global Heat Loss |
| title_sort | magma accretion model for the formation of oceanic lithosphere implications for global heat loss |
| url | http://dx.doi.org/10.1155/2010/146496 |
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