Start |Grid View | Author Index | View Uploaded Presentations | Meeting Information

GSA Annual Meeting in Phoenix, Arizona, USA - 2019

Paper No. 70-1
Presentation Time: 1:45 PM

HIGH RATES OF TRACER GAS TRANSPORT IN A DEEP FRACTURED BASALT (Invited Presentation)


STAUFFER, Philip H.1, RAHN, Thom2, ORTIZ, John P.1, BOUKHALFA, Hakim3, BEHAR, Hannah4 and SNYDER, Emily E.5, (1)EES-16, Earth and Environmental Sciences Division, Los Alamos National Laboratory, Mailstop T003, Los Alamos, NM 87545, (2)EES-14, Earth and Environmental Sciences Division, Los Alamos National Laboratory, Mailstop T003, Los Alamos, NM 87545, (3)Los Alamos National Laboratory, Los Alamos, NM 87545, (4)Water Resources Science Graduate Program, University of Minnesota, Duluth, MN 55811; Los Alamos National Lab, Earth and Environmental Science, P.O. Box 1663, Los Alamos, NM 55811, (5)EES-16, Earth & Environmental Sciences Division, Los Alamos National Laboratory, Mailstop T003, Los Alamos, NM 87545; Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, New Mexico Institute of Mining and Technology, Soccorro, NM 87801

In the phenomenon known as barometric pumping, atmospheric pressure fluctuations contribute to the motion of gases in the vadose zone. While the resulting gas transport is often negligible in homogeneous media, rates of transport in fractured media can be significant. We present results from a tracer test that was conducted to characterize deep subsurface fractured basalt and investigate the effects of barometric pumping on gaseous contaminant mobility. The tracer testing provided data to constrain permeability, porosity, and diffusivity in a numerical representation of the experiment. The numerical model was then used to simulate gas flow and transport under fluctuating pressure conditions. Results from the tracer test and simulations suggest that barometric pumping induces 10x to 100x more mixing in the basalt than standard diffusive theory would predict. Further, within the basalt fractures, estimates of average linear velocity reach maximums of nearly 1000 m/day.
Handouts
  • Paper_339331_presentation_3025_0.pdf (6.7 MB)

    • Session No. 70

    T146. Field Tracer Studies for Aquifer Characterization
    Sunday, 22 September 2019: 1:30 PM-5:30 PM
    Room 105BC, West Building (Phoenix Convention Center)
    Geological Society of America Abstracts with Programs. Vol. 51, No. 5
    doi: 10.1130/abs/2019AM-339331
    © Copyright 2019 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.
    Back to: T146. Field Tracer Studies for Aquifer Characterization
    Previous Abstract | Next Abstract >>