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oai:figshare.com:article/32640198 2026-10-01T16:33:18Z portal_1172 item_type_8 month_year_10_2026

Glacial geomorphology - Breiðamerkurjökull, southeast Iceland Amy Lally (21000955) PUREID: 613765323 Glacier Iceland glacial geomorphology UAV GPR geophysics This work aims to improve our understanding of meltwater processes and landscape evolution during deglaciation through repeated geomorphology mapping. Examining landforms in modern settings enables more confident links to be made between process and form, improving landform identification across palaeo-ice sheet landscapes and accuracy of numerical ice-flow models. The study area, which contains the ice margin of the central flow unit of Breiðamerkurjökull (Esjufjallajökull) and the associated foreland, was repeatedly surveyed using uncrewed aerial vehicles (UAVs) from September 2021 to May 2023.Using the centimetre scale outputs, a four-map glacial geomorphological time-series was created which documents sixteen landform types across the foreland deglaciated between 2010 and 2023. Landforms include those created by subglacial processes (e.g. flutings), post-depositional processes (e.g. sandar pits), glaciofluvial erosion (e.g. spillways) and deposition (e.g. eskers). The time-series was compared to existing maps of Breiðamerkurjökull, produced between 1945 and 2018. Recessional push moraines were not observed. A new landform type was identified, hummocky meltwater tracts, which potentially provide evidence for high meltwater supply to subglacial bed.Changes were quantified between all four datasets, enabling the identification of dominant processes and six distinct change zones (e.g. stable areas, buried ice terrain). The short time period between datasets allowed for seasonal signatures, such as glaciofluvial deposition, to be detected. Ground penetrating radar (GPR) surveys provided additional contextual information related to subglacial topography. The results captured different modes of ice loss (i.e. thinning and retreat) and provided insights into the transient nature of landforms in ice-marginal environments. The outputs also indicate this section of the glacier is undergoing passive retreat and downwasting. Buried ice underlying pitted sandar areas is undergoing secondary deglaciation and may take decades to stabilise.Two detailed case studies were undertaken allowing the development and refinement of process-form and landsystem models. The first case study focused on englacial eskers. Repeated surveying and GPR data suggest these features have poor preservation potential, which has implications for reconstructing palaeo-ice sheets using preserved landforms alone. The second case study captured a shift in landform assemblage across the eastern study site since 2017, which was attributed to a local ice-flow switch and topographic variations. Developed process-form and landsystem models were applied to a palaeo-example - the Pakowki Lake region, southeast Alberta which was once covered by the Laurentide Ice Sheet. Geomorphic and topographic comparisons enabled existing reconstructions of palaeo-ice dynamics in the region to be corroborated.This research highlights the valuable role of UAVs and repeated surveying in enhancing our understanding of rapidly changing environments, refining process-form regimes and landsystem models. The increasing availability of high-resolution imagery across ancient landscapes coupled with refined process-form regimes will enable improved palaeo-ice sheet reconstructions. Future work could adopt a similar workflow to examine landscape evolution at other deglaciating margins.<br> 2026-10-01T16:33:18Z Text Thesis 10.17034/32640198.v1 https://figshare.com/articles/thesis/Glacial_geomorphology_-_Brei_amerkurj_kull_southeast_Iceland/32640198 All Rights Reserved