Articles | Volume 4, issue 3
Research article
10 Aug 2016
Research article |  | 10 Aug 2016

The CAIRN method: automated, reproducible calculation of catchment-averaged denudation rates from cosmogenic nuclide concentrations

Simon Marius Mudd, Marie-Alice Harel, Martin D. Hurst, Stuart W. D. Grieve, and Shasta M. Marrero

Abstract. We report a new program for calculating catchment-averaged denudation rates from cosmogenic nuclide concentrations. The method (Catchment-Averaged denudatIon Rates from cosmogenic Nuclides: CAIRN) bundles previously reported production scaling and topographic shielding algorithms. In addition, it calculates production and shielding on a pixel-by-pixel basis. We explore the effect of sampling frequency across both azimuth (Δθ) and altitude (Δϕ) angles for topographic shielding and show that in high relief terrain a relatively high sampling frequency is required, with a good balance achieved between accuracy and computational expense at Δθ = 8° and Δϕ = 5°. CAIRN includes both internal and external uncertainty analysis, and is packaged in freely available software in order to facilitate easily reproducible denudation rate estimates. CAIRN calculates denudation rates but also automates catchment averaging of shielding and production, and thus can be used to provide reproducible input parameters for the CRONUS family of online calculators.

Short summary
Cosmogenic nuclide concentrations are widely used to calculate catchment-averaged denudation rates. Despite their widespread use, there is currently no open source method for calculating such rates, and the methods used to calculate catchment-averaged denudation rates vary widely between studies. Here we present an automated, open-source method for calculating basin averaged denudation rates, which may be used as a stand-alone calculator or as a front end to popular online calculators.