Controls on Ice Cliff Formation, Distribution and Characteristics on
Debris-Covered Glaciers
Abstract
Ice cliff distribution plays a major role in determining the melt of
debris-covered glaciers but its controls are largely unknown. We
assembled a dataset of 37537 ice cliffs and determined their
characteristics across 86 debris-covered glaciers within High Mountain
Asia (HMA). We complemented this dataset with the analysis of 202 cliff
formation events from multi-temporal UAV observations for a subset of
glaciers. We find that 38.9% of the cliffs are stream-influenced,
19.5% pond-influenced and 19.7% are crevasses. Surface velocity is the
main predictor of cliff distribution at both local and glacier scale,
indicating its dependence on the dynamic state and hence evolution stage
of debris-covered glacier tongues. Supraglacial ponds contribute to
maintaining cliffs in areas of thicker debris, but this is only possible
if water accumulates at the surface. Overall, total cliff density
decreases exponentially with debris thickness as soon as debris gets
thicker than 10 cm.