Modelling Reveals an Ice Field on the Arid Northeastern Tibetan Plateau During Marine Isotope Stage 6

Abstract The long‐standing hypothesis that an ice sheet covered the Tibetan Plateau during the Last Glacial Maximum (LGM) has been refuted. Further research has indicated that the Plateau experienced more extensive glacial expansion during Marine Isotope Stage (MIS) 6 than during the LGM. However, whether the Tibetan Plateau hosted large‐scale glacier systems during MIS 6 remains an open question. Here, we selected the arid Qilian Shan of the northeastern Tibetan Plateau to reconstruct 90 m resolution glacier extents for three major glaciations over the past 190 ka. Integration of geomorphological and chronological evidence with a glacial model shows that glacial extent was least extensive during MIS 2, was intermediate during MIS 3b, and was most extensive during MIS 6. The modelled ice extents are consistently larger than previously reported. Specifically, an ice field with an area of ∼5.61 × 10 4 km 2 likely developed on the western Qilian Shan during MIS 6.