T249 From Pores to Mountains, and Minutes to Millennia (Posters): Session Dedicated to the Contributions of Rob Bowman, Fred Phillips, and John Wilson

Tuesday, 27 September 2016
9:00 AM - 6:30 PM
Exhibit Hall E/F

TIME-DEPENDENT AGE DISTRIBUTIONS AND THEIR IMPLICATIONS FOR THE INTERPRETATION OF ENVIRONMENTAL TRACERS

Paper number: T249-7
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Abstract

Transient forcing modulates flow and age distributions in hydrologic systems, resulting in a dynamic response that is critical to interpret observations and predict the effects of current and future stresses. In this work, we propose three simple, yet insightful, conceptualizations of hydrologic systems: (i) a linear, zero-dimensional reservoir; (ii) a one-dimensional system with advection and dispersion, and (iii) a non-linear, zero-dimensional reservoir. We present analytical solutions for the flow and age distributions in each of these conceptualizations, and then use these solutions to explore the implications of flow dynamics in the interpretation of environmental tracers. A distinctive attribute of the age distributions under transient flow is the emergence of time-varying multimodality, which reflects changes in the characteristic time scales for transport. In addition, our theoretical analysis shows that the estimated environmental tracer ages inherit some of the dynamic nature of the forcing; however, the magnitude of the changes are of the order of the uncertainty found in commonly used asymptotic decay methods.

Geological Society of America Abstracts with Programs. Vol. 48, No. 7

doi: 10.1130/abs/2016AM-287842

© Copyright 2016 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.