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Titel |
The hydrothermal power of oceanic lithosphere |
VerfasserIn |
C. J. Grose, J. C. Afonso |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1869-9510
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Digitales Dokument |
URL |
Erschienen |
In: Solid Earth ; 6, no. 4 ; Nr. 6, no. 4 (2015-10-21), S.1131-1155 |
Datensatznummer |
250115518
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Publikation (Nr.) |
copernicus.org/se-6-1131-2015.pdf |
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Zusammenfassung |
We have estimated the power of ventilated hydrothermal heat transport, and
its spatial distribution, using a set of recently developed plate models
which highlight the effects of axial hydrothermal circulation and thermal
insulation by oceanic crust. Testing lithospheric cooling models with these
two effects, we estimate that global advective heat transport is about 6.6 TW,
significantly lower than most previous estimates, and that the fraction
of that extracted by vigorous circulation on the ridge axes (< 1 My old) is
about 50 % of the total, significantly higher than previous estimates. These
new estimates originate from the thermally insulating properties of oceanic
crust in relation to the mantle. Since the crust is relatively insulating,
the effective properties of the lithosphere are "crust dominated" near ridge
axes (a thermal blanketing effect yielding lower heat flow) and gradually
approach mantle values over time. Thus, cooling models with crustal
insulation predict low heat flow over young seafloor, implying that the
difference of modeled and measured heat flow is due to the heat transport
properties of the lithosphere, in addition to ventilated hydrothermal
circulation as generally accepted. These estimates may bear on important
problems in the physics and chemistry of the Earth because the magnitude of
ventilated hydrothermal power affects chemical exchanges between the oceans
and the lithosphere, thereby affecting both thermal and chemical budgets in
the oceanic crust and lithosphere, the subduction factory, and the convective
mantle. |
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