Meteoric Beryllium-10 as a Tracer of Erosion Due to Postsettlement Land Use in West-Central Minnesota, USA

Nicolas A. Jelinski, Benjamin Campforts, Jane K. Willenbring, Thomas E. Schumacher, Sheng Li, David A. Lobb, Sharon K. Papiernik, Kyungsoo Yoo

Research output: Contribution to journalArticle

Abstract

Meteoric beryllium-10 (10Bem, t1/2 = 1.4 Myr) is a cosmogenic radionuclide that remains largely underutilized for deriving hillslope-scale estimates of erosion on uplands under conditions of land use change. We applied two different models for estimating erosion rates from observed 10Bem concentrations (a one-dimensional model predicting vertical profiles of 10Bem within hillslope soils [loss only, diffusion only, LODO] and a two-dimensional model predicting the concurrent evolution of hillslope topography and 10Bem distributions via bioturbation, chemical mobility, and surface erosion [Be2D]). Both models were used to derive pre-European and post-European settlement erosion rates (Enat and Epost, respectively) across paired cultivated and uncultivated hillslopes in west-central Minnesota, USA. Epost estimates from 10Bem were compared to Epost estimates derived from 137Cs inventories and the process-based Water and Tillage Erosion Model (WaTEM). The results from these models suggest that erosion rates from upper positions on the cultivated hillslope have increased from an average of 0.047 mm/year under natural conditions to Epost values of 3.09 mm/year. The Be2D and LODO models, on average, produced Epost estimates that were similar in magnitude to WaTEM and 137Cs conversion models. This numerical convergence does not imply absolute 10Bem model accuracy, particularly when considering the uncertainties inherent in each approach, but it does suggest that the orders of magnitude increase in estimated erosion rates from Enat to Epost is robust. Additionally, the pattern of Epost estimates produced using 10Bem conversion models is supported by the distribution of soil inorganic carbon at the study site. Our results demonstrate that 10Bem can provide reasonable estimates of both predisturbance and postdisturbance erosion rates in landscapes that have undergone extensive human modification.

Original languageEnglish (US)
Pages (from-to)874-901
Number of pages28
JournalJournal of Geophysical Research: Earth Surface
Volume124
Issue number4
DOIs
StatePublished - Apr 2019

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Keywords

  • agriculture
  • beryllium-10
  • erosion
  • radionuclide

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