Channelized fluid flow in oceanic crest reconciles heat-flow and permeability data

A. T. Fisher, Keir Becker

Research output: Contribution to journalArticle

141 Citations (Scopus)

Abstract

Hydrothermal fluid circulation within the sea floor profoundly influences the physical, chemical and biological state of the crust and the oceans. Circulation within ridge flanks (in crust more than 1 Myr old) results in greater heat loss and fluid flux than that at ridge crests and persists for millions of years, thereby altering the composition of the crust and overlying ocean. Fluid flow in oceanic crust is, however, limited by the extent and nature of the rock's permeability. Here we demonstrate that the global data set of borehole permeability measurements in uppermost oceanic crust defines a trend with age that is consistent with changes in seismic velocity. This trend - which indicates that fluid flow should be greatly reduced in crust older than a few million years - would appear to be inconsistent with heat-flow observations, which on average indicate significant advective heal loss in crust up to 65 Myr old. But our calculations, based on a lateral flow model, suggest that regional-scale permeabilities are much higher than have been measured in boreholes. These results can be reconciled if most of the fluid flow in the upper crust is channelized through a small volume of rock, influencing the geometry of convection and the nature of fluid-rock interaction.

Original languageEnglish (US)
Pages (from-to)71-74
Number of pages4
JournalNature
Volume403
Issue number6765
DOIs
StatePublished - Jan 6 2000

Fingerprint

heat flow
fluid flow
permeability
crust
oceanic crust
borehole
rock
fluid
ocean
seismic velocity
hydrothermal fluid
upper crust
seafloor
convection
geometry
loss
trend

ASJC Scopus subject areas

  • General

Cite this

Channelized fluid flow in oceanic crest reconciles heat-flow and permeability data. / Fisher, A. T.; Becker, Keir.

In: Nature, Vol. 403, No. 6765, 06.01.2000, p. 71-74.

Research output: Contribution to journalArticle

@article{a8bfd89cadf9483895df3262542b8f82,
title = "Channelized fluid flow in oceanic crest reconciles heat-flow and permeability data",
abstract = "Hydrothermal fluid circulation within the sea floor profoundly influences the physical, chemical and biological state of the crust and the oceans. Circulation within ridge flanks (in crust more than 1 Myr old) results in greater heat loss and fluid flux than that at ridge crests and persists for millions of years, thereby altering the composition of the crust and overlying ocean. Fluid flow in oceanic crust is, however, limited by the extent and nature of the rock's permeability. Here we demonstrate that the global data set of borehole permeability measurements in uppermost oceanic crust defines a trend with age that is consistent with changes in seismic velocity. This trend - which indicates that fluid flow should be greatly reduced in crust older than a few million years - would appear to be inconsistent with heat-flow observations, which on average indicate significant advective heal loss in crust up to 65 Myr old. But our calculations, based on a lateral flow model, suggest that regional-scale permeabilities are much higher than have been measured in boreholes. These results can be reconciled if most of the fluid flow in the upper crust is channelized through a small volume of rock, influencing the geometry of convection and the nature of fluid-rock interaction.",
author = "Fisher, {A. T.} and Keir Becker",
year = "2000",
month = "1",
day = "6",
doi = "10.1038/47463",
language = "English (US)",
volume = "403",
pages = "71--74",
journal = "Nature",
issn = "0028-0836",
publisher = "Nature Publishing Group",
number = "6765",

}

TY - JOUR

T1 - Channelized fluid flow in oceanic crest reconciles heat-flow and permeability data

AU - Fisher, A. T.

AU - Becker, Keir

PY - 2000/1/6

Y1 - 2000/1/6

N2 - Hydrothermal fluid circulation within the sea floor profoundly influences the physical, chemical and biological state of the crust and the oceans. Circulation within ridge flanks (in crust more than 1 Myr old) results in greater heat loss and fluid flux than that at ridge crests and persists for millions of years, thereby altering the composition of the crust and overlying ocean. Fluid flow in oceanic crust is, however, limited by the extent and nature of the rock's permeability. Here we demonstrate that the global data set of borehole permeability measurements in uppermost oceanic crust defines a trend with age that is consistent with changes in seismic velocity. This trend - which indicates that fluid flow should be greatly reduced in crust older than a few million years - would appear to be inconsistent with heat-flow observations, which on average indicate significant advective heal loss in crust up to 65 Myr old. But our calculations, based on a lateral flow model, suggest that regional-scale permeabilities are much higher than have been measured in boreholes. These results can be reconciled if most of the fluid flow in the upper crust is channelized through a small volume of rock, influencing the geometry of convection and the nature of fluid-rock interaction.

AB - Hydrothermal fluid circulation within the sea floor profoundly influences the physical, chemical and biological state of the crust and the oceans. Circulation within ridge flanks (in crust more than 1 Myr old) results in greater heat loss and fluid flux than that at ridge crests and persists for millions of years, thereby altering the composition of the crust and overlying ocean. Fluid flow in oceanic crust is, however, limited by the extent and nature of the rock's permeability. Here we demonstrate that the global data set of borehole permeability measurements in uppermost oceanic crust defines a trend with age that is consistent with changes in seismic velocity. This trend - which indicates that fluid flow should be greatly reduced in crust older than a few million years - would appear to be inconsistent with heat-flow observations, which on average indicate significant advective heal loss in crust up to 65 Myr old. But our calculations, based on a lateral flow model, suggest that regional-scale permeabilities are much higher than have been measured in boreholes. These results can be reconciled if most of the fluid flow in the upper crust is channelized through a small volume of rock, influencing the geometry of convection and the nature of fluid-rock interaction.

UR - http://www.scopus.com/inward/record.url?scp=0034610787&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034610787&partnerID=8YFLogxK

U2 - 10.1038/47463

DO - 10.1038/47463

M3 - Article

VL - 403

SP - 71

EP - 74

JO - Nature

JF - Nature

SN - 0028-0836

IS - 6765

ER -