Glazer’s participation on the AT18-07 expedition to the Juan de Fuca Ridge Flank was part of a collaborative effort researching geochemistry and microbiology of subsurface fluids obtained from CORK observatories. During this cruise Glazer’s primary goals were to conduct in situ electrochemical and optical oxygen measurements during real-time fluid sampling on ROV Jason-II, and to recover and redeploy an in situ electrochemical analyzer on a time-series instrument sled (GeoMICROBE) deployed to 1301A in 2010. In combination with temperature and optical oxygen measurements, in situ voltammetry was a useful real-time diagnostic indicator of successful connection to the CORK Fluid Delivery System. Preliminary results suggest delivery of fluids to seafloor samplers during AT18-07, especially at 1362B and 1362A, were highest integrity, lowest oxygen, formation fluids collected to date.
