Environmental Controls on Post-Little Ice Age Landslide Distribution Around the South Patagonian Icefield

Understanding landslide (LS) distribution in deglaciated mountains is key to landscape evolution and geohazard risk. We present an orogen-scale assessment of 1,691 Post-Little Ice Age (LIA) LSs (91% shallow) along the South Patagonian Icefield (SPI, 48–52°S) margins. Mapped via high-resolution multitemporal imagery (2010–2025) and multi-operator validated, kernel densities (10 km bandwidth) show clustering in western and southern SPI—central peak, northwest secondary—amid ~20% ice loss (since the end of the LIA) and uplift >40 mm/yr.

Environmental variables from LS/non-LS areas fed Bayesian horseshoe variable selection. Sparse Gaussian process regression (R²=0.96, SPAEF ≥0.85) identified precipitation, fault density, and uplift as dominant controls. Precipitation destabilizes slopes via pore pressures, triggering shallow LSs (positive correlation); fault density signals structural weakness/seismic facilitation; uplift shows complex negative LS correlation, as active deformation/steep slopes favor erosion over accumulation, reducing LS buildup. Lithology, permafrost, retreat rates exert weaker, context-dependent influences. LS versus non-LS distinctions underscore the value of integrating correlation-based and predictive approaches. Coupled climate-deglaciation-tectonics govern landslide distribution in the SPI.

Critically, ~17% of LSs overlap glacial lake upslope areas (30 m buffer), preconditioning glacier lake outburst flood risks at, e.g. Torre Glacier's ~8 Mm³ failure—shallow dominance may temper severity, sea-proximal cases extend threats. Findings illuminate paraglacial responses to glacier retreat, offering predictive hazard frameworks for warming cryosphere.