Noble gas isotope data from field campaigns sampling groundwater in Umatilla, Oregon during September 2020 and in Tucson, Arizona during November 2021

Abstract

This project developed a novel seawater and groundwater noble gas isotope extraction technique, building on an approach pioneered by Dr. Steve Emerson that involves equilibration of headspace and water followed by vacuum removal and disposal of almost all the water. Corrections are then made for the lost noble gas in the water, using precisely measured mass and volume. The method uses 6-liter stainless steel flasks with Nupro valves for improved leak-tightness. This extraction technique made it possible to measure neon as well as the heavier noble-gas isotopes, all from the same sample, providing a constraint on "excess air" using the neon. Field campaigns sampling groundwater were conducted in Oregon and Arizona. Data from these campaigns are deposited here.

For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/897484