Depletion of a brine layer at the base of ridge-crest hydrothermal systems

Mathematics – Logic

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

11

Scientific paper

The variable salinity of fluid venting from mid-ocean ridges is indicative of mixing between hydrothermal seawater and fluids that have undergone supercritical phase separation. In order to study the stability of a brine-saturated layer that may form in the lowermost part of the hydrothermal system, we have performed numerical simulations of a system that has returned into the subcritical regime. For typical geological parameters, it is shown that the interface between the brine layer and the overlying fluids is not very stable, but vanishes by one of two dynamical mechanisms: convective breakdown or vertical migration. This contradicts the conventional picture of a steady, layered convective system in which the brine is depleted only by dispersion and diffusion across the interface. The depletion mechanism depends on the fluid-dynamical stability of the brine layer. Convection within the brine layer results either in the convective breakdown (for low excess salinity of the brine, as compared to seawater) or the upward migration of the interface (for higher excess salinities). Consequently, the depletion times are much shorter than for models with pure dispersion/diffusion across the interface. If the brine layer is static, high-chlorinity liquid is entrained slowly by the convecting overlying fluids, leading to downward migration of the interface. This gradual depletion of the brine layer results in almost constant vent salinities, in agreement with measured salinities of chronic high-chlorinity vents.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Depletion of a brine layer at the base of ridge-crest hydrothermal systems does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Depletion of a brine layer at the base of ridge-crest hydrothermal systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Depletion of a brine layer at the base of ridge-crest hydrothermal systems will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-737469

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.