GlaRe, a GIS tool to reconstruct the 3D surface of palaeoglaciers

Abstract

Glacier reconstructions are widely used in palaeoclimatic studies and this paper presents a new semi-automated method for generating glacier reconstructions: GlaRe, is a toolbox coded in Python and operating in ArcGIS. This toolbox provides tools to generate the ice thickness from the bed topography along a palaeoglacier flowline applying the standard flow law for ice, and generates the 3D surface of the palaeoglacier using multiple interpolation methods. The toolbox performance has been evaluated using two extant glaciers, an icefield and a cirque/valley glacier from which the subglacial topography is known, using the basic reconstruction routine in GlaRe. Results in terms of ice surface, ice extent and equilibrium line altitude show excellent agreement that confirms the robustness of this procedure in the reconstruction of palaeoglaciers from glacial landforms such as frontal moraines

Younger Dryas glaciers and climate in the Mourne Mountains, Northern Ireland

“…Three‐dimensional reconstructions of glaciers within, and/or emanating from, these cirques were generated using the GIS tool of Pellitero et al . (). In each case, a basal shear stress of 100 kPa was applied, using a step length of 10 m (for details see Pellitero et al ., ).…”

“…(). In each case, a basal shear stress of 100 kPa was applied, using a step length of 10 m (for details see Pellitero et al ., ).…”

Evolution of high-Arctic glacial landforms during deglaciation

“…Ultimately, complex debris-rich and ice-rich landform assemblages at adjacent sites (Midgley et al, 2013;; this study) highlight the need for care when assessing the palaeoglaciological significance and likely long-term preservation potential of ice-marginal landscapes in the geomorphological record. Appropriate understanding of landform character and landform censoring or degradation history is an important consideration for obtaining appropriate ages for glacial landforms (e.g., Kirkbride and Winkler, 2012;Çiner et al, 2015;Crump et al, 2017;Tonkin et al, 2017) and for glacier reconstructions (e.g., Benn and Hulton, 2010;Pellitero et al, 2016) where moraines are used to constrain the extent and vertical dimensions of former glaciers. As such, a better understanding of this landform type with a mix of debris-rich and ice-rich substrate will prove valuable to assessing age and palaeoclimatic interpretations.…”

“…The burial and long-term preservation of relict ice is of interest as a potential palaeoglaciological and palaeoenvironmental archive (e.g., Sugden et al, 1995;Schäfer et al, 2000;Murton et al, 2005;Waller et al, 2012). In addition, understanding the preservation history of buried ice will also assist with appropriate landform age determination (e.g., Kirkbride and Winkler, 2012;Çiner et al, 2015;Tonkin et al, 2017;Crump et al, 2017) and assist with former glacier reconstruction (e.g., Benn and Hulton, 2010;Pellitero et al, 2016). This work is important because it advances our understanding of the buried ice ablation process by providing insight into the deglaciation dynamics of a high-Arctic glacier foreland over a decadal timescale and it contributes to our knowledge of how debris-covered cryospheric systems respond to ameliorating climatic conditions.…”

Late Pleistocene climate of the northern Iberian Peninsula: New insights from palaeoglaciers at Fuentes Carrionas (Cantabrian Mountains)

“…A 3D glacial surface for each phase, either dated or inferred from morphostratigraphy (the case of YD) was reconstructed using glacial landforms and deposits, which had been previously mapped (Pellitero, ) and whose morphostratigraphical relationship had previously been described (Pellitero, ). Glacier surface reconstruction for each of the phases was performed using GlaRe (Pellitero et al , ), which is based on the Benn and Hulton () approach. A standard 100‐kPa shear stress was assumed, unless geomorphological evidence (such as lateral moraines) suggested otherwise.…”