A NEW FLUID AND GEOCHEMICAL FLUX METER FOR SURFACE MEASUREMENTS IN CONVERGENT MARGIN AND RIDGE FLANK ENVIRONMENTS

Kevin M. Brown, Allan W. Sauter, LeRoy M. Dorman, Scripps Institution of Oceanography, UCSD, 9500 Gilman Drive, La Jolla, CA 92093-0215, USA.

A key component of geochemical and hydro-tectonic studies in both convergent and divergent margins is the accurate determination of the magnitudes and spatial distribution of flux rates of fluid/geochemical components in the system. We present the design and initial results from a new type of water and geochemical flux meter that is capable, for example, of measuring diffuse linear fluid velocities through the sediment surface on the order of 0.1 to 100 mmy-1, allowing direct measurements to be made for the first time at low flux-rate vents and regions of slow diffuse flow. Reported here are results from laboratory calibration tests and the first deployment of the flux meter in Monterey Bay off California in August of 1995, where it succeeded in measuring advective flow rates of ~4 to 5 mmy-1 close to an active fluid vent while attached to a Scripps ONR OBS.

Last Revised: 9 May 1996