Cirques in the Transantarctic Mountains reveal controls on glacier formation and landscape evolution

ACME2: An extended toolbox for automated cirque metrics extraction

“…Gardner, 1987;Evans and Cox, 1995;Sanders et al, 2012;Evans, 2021). The presence of cirques is a long-lasting indicator of past glaciation, so cirque morphology has been used to infer palaeoclimate and environmental conditions such as solar radiation, cloud cover, wind direction, and the magnitude of past glaciations (Nelson and Jackson, 2002;Evans, 1977Evans, , 2006Mîndrescu et al, 2010;Barr and Spagnolo, 2015;Oien et al, 2020Oien et al, , 2022Li et al, 2023;Barr et al, 2023). Cirques have also been used as evidence of the role of glacial erosion in limiting mountain heights, commonly referred to as the "glacial buzzsaw" hypothesis (Brozović et al, 1997;Mitchell and Montgomery, 2006;Egholm et al, 2009;Mîndrescu and Evans, 2014).…”

“…This requires three inputs: cirque outlines (polygons), threshold midpoints, and a DEM. This toolbox has been used to extract cirque metrics and infer palaeoclimate conditions in various settings worldwide, including: Britain and Ireland (Barr et al, , 2019, the Guadarrama and Somosierra mountains in Spain (Pedraza et al, 2019), the Faeroe Islands (Wallick and Principato, 2020), High Mountain Asia ( Zhang et al, 2020( Zhang et al, , 2021Li et al, 2023), and Antarctica (Barr et al, 2022(Barr et al, , 2023. Use of DEMs allowed ACME to calculate new descriptors such as hypsometric integral, mean slope and 3D area.…”