Modelling Haizishan paleo ice caps in the SE Tibetan Plateau during the last glaciation

This study advances our understanding of Quaternary glaciation in the southeastern Tibetan Plateau by integrating geomorphic evidence with numerical ice sheet modeling to constrain paleoclimate and ice dynamics. We focus on the Haizishan Plateau, a key region with well-preserved landforms (cirques, U-shaped valleys, moraines) and cosmogenic nuclide chronology indicating major glaciations during MIS 2 and MIS 6. Using these geomorphic and chronological constraints, we first reconstructed the Last Glacial Maximum (LGM) ice margin and then applied the PaleoIce flowline model to estimate paleo-ice thickness and surface elevation. These independent geomorphic reconstructions were then compared to the results of three-dimensional paleo-ice sheet simulations performed with the Parallel Ice Sheet Model (PISM), which were driven by inferred paleoclimate conditions.

The PISM simulations indicate an LGM characterized by a temperature depression of ~4°C and precipitation levels 60–70% of modern values. The model successfully replicates the regional ice cap evolution, showing limited glacial extent during MIS 3 and restricted advances in MIS 4. Critically, the simulated ice configuration aligns well with the geomorphically reconstructed evidence, including glacial lineation patterns, landform zonation, and overall extent, validating the model's performance. Our findings demonstrate the power of combining geomorphic reconstruction with dynamical modeling to refine the glacial and climatic history of high-mountain regions.