Document Type
Thesis
Abstract
The goal of this study is to test a steady state model of Nia transport through small watersheds and validate this model as an effective method for dating young freshwaters through comparison to the SF, tracer method. The existing tracers used in dating freshwater are pulse tracers, which makes them unreliable for long term use. Na is a natural radionuclide produced in the atmosphere and delivered to the surface as a dissolved ion in precipitation. Fluxes measured in rainfall between 2012 and 2014 indicate that while seasonally variable, from year to year total 22Na fallout is consistent around 150 mBq/m2. We test the steady state model, defined as 22Na inputs from precipitation equaling the flux out of 22Na in stream discharge plus radioactive decay, in Pagonia watershed located in Williamsburg, Virginia. Using the known decay rate of 22Na, the inputs from precipitation, and the measured 22Na in stream discharge, we calculate the Pagonia watershed age at 10.1-12.3 years old. This result agrees with the SF. model result of 12.2 years.
Date Awarded
2015
Department
Geology
Advisor 1
James M. Kaste
Recommended Citation
Burton, Alana, "Testing a Steady State Model of 22Na Transport in Small Watersheds for the Purpose of Dating Young Freshwaters" (2015). Geology Senior Theses. William & Mary. Paper 332.
https://scholarworks.wm.edu/geologyseniors/332
