RECONSTRUCTION OF THE DEGLACIAL FENNOSCANDIAN SHORELINE AN UPDATED AND IMPROVED MODEL

Abstract

This work presents a fully numeric model of the shoreline displacement of Fennoscandia and neighbouring areas for the past 20000 years since the last glacial maximum. 3126 relative shoreline points from different databases have been combined and recalibrated with the ‘OxCal’ calibration software. The data has been resampled dependent on their geographical position in order to create relative shoreline curves for as many locations as possible (resulting in 2866 curves in total). These curves have been used for optimizing glacio-isostatic adjustment (GIA) curves that represent location-specific GIA models. This led to an empiric model for the glacio-isostatic adjustment covering the entirety of Fennoscandia. Combined with previously published elevation data, data for the eustatic variability and a deglaciation model, raster data sets have been calculated for the paleo-topography of Fennoscandia and its shoreline. The resulting model is overall consistent with other models for the shoreline displacement and with different simulations for the glacio-isostatic adjustment but shows lower accuracy for Denmark and Skåne. The model is written in the R programming language and provided as a package that includes an interface to allow an easy calculation of models for any time period without need to store several hundred GB of data.