Cirque morphology in relation to ice-sheet retreat in central West Greenland and Disko Island (Qeqertarsuaq)

Cirques provide valuable geomorphological evidence of past glacier activity, yet their distribution and morphology remain poorly documented across much of Greenland. Here we present the first regional-scale inventory and morphometric analysis of 527 cirques from central West Greenland and Disko Island, using high-resolution ArcticDEM data and automated metric extraction (ACME 2.0). Cirques exhibit a strong north-facing orientation and wide variability in planform dimensions, relief, slope and curvature. Internal covariance among metrics demonstrates a coherent range of cirque forms bounded by shallow, low-relief basins and steep, deeply incised cirques with pronounced headwalls. Cirque morphometric parameters show significant relationships with their inferred exposure intervals derived from published ice-margin retreat isochrons. Specifically, cirques inferred to have been exposed earlier (≥13-14 ka) display greater relief, steeper mean slopes, larger proportions of slopes steeper than 33° and stronger headwall curvature, whereas cirques exposed later (≤10-11 ka) are smaller, shallower and less morphologically complex. The steepest cirques occur immediately outside the reconstructed 13 ka ice-margin position, while the shallowest cirques align with the youngest exposure ages, consistent with prolonged ice-sheet coverage following regional deglaciation. These relationships persist despite substantial differences in bedrock geology across the study area, implying that lithology does not exert a first-order control on overall cirque form. Together, these findings demonstrate that cirque morphology in central West Greenland is closely associated with the interaction of topography, aspect-dependent mass-balance conditions, and the sequence of ice-sheet retreat. The results demonstrate systematic relationships between cirque morphology and inferred patterns of ice-sheet retreat, providing new insight into the evolution of small peripheral glacier systems along the western Greenland Ice Sheet margin, while also highlighting the importance of lithological, topographic, and glacial inheritance when interpreting cirques as palaeoenvironmental indicators.