Noble gas concentrations and saturation anomalies from water samples collected on R/V Atlantis cruise AT50-15 in the Juan de Fuca Ridge from August to September 2023

This dataset contains the analytical results from 126 samples collected from the complex hydrothermal plume system overlying, and dispersing away from, the Endeavour segment of the Juan de Fuca Ridge. The samples were collected in August and September 2023 aboard R/V Atlantis cruise AT50-15 and analyzed at WHOI in the isotope geochemistry facility. The samples were collected, primarily, to trace dilution within a hydrothermal plume whose physical dispersion was predicted from theoretical modelling and traced by the AUV Sentry. Multiple tracers were sampled for, from both the Sentry AUV and from vertical casts of the Texas A&M's trace metal clean CTD-rosette, with noble gas samples collected from the CTD-rosette only because of sample volume requirements. Measurement of these samples for XS3He, in particular, provides a frame of reference against which all other trace element data in the same samples can be normalized to allow for effects that are due to dilution rather than any biogeochemical reactivity.