How Salty are Lost City Vents?

A very special instrument that we will deploy into at least one of the hydrothermal vents at Lost City is a “temperature-resistivity probe” (resistivity is a proxy for salinity). This probe makes continuous measurements of the salt content of fluids (along with temperature) and will give us a measure of chemical fluctuations in a time base of 15 minute sampling. We have seen correlations in chemical content with tides in the studies in hot spring systems at the Endeavour Segment of the Juan de Fuca Ridge, but do not yet know how Lost City fluids may vary with the changing phases of the Moon. Ideally, these instruments will be left in place for the duration of our stay at Lost City to acquire 3 weeks of data.