A GLACIER-DERIVED RECORD OF TROPICAL TEMPERATURE DURING TERMINATION 1 FROM THE CORDILLERA ORIENTAL, SOUTHERN PERU

Deciphering the pattern of climate behaviour during the last glacial–interglacial transition is key to understanding the mechanisms responsible for terminations. This is particularly true for the tropics, which, as the primary source of both heat and water vapour, exert a profound influence on global climate. We present a glacier record from the SE Peruvian Andes, constrained with cosmogenic ¹⁰Be surface-exposure ages, documenting temperature change during the first half of Termination 1. Our data indicate that deglaciation, and thus atmospheric warming, was coincident with southward displacement of the ITCZ during Heinrich Stadial 1 (HS1) and increased precipitation in the southern tropical Andes, confirming that glaciers here are primarily responsive to temperature. On a broader scale, this pattern aligns with findings from higher southern latitudes that suggest HS1 was a period of widespread pronounced warming. Additionally, our record indicates that HS1 deglaciation was interrupted by a brief readvance approximately 16 Ka. We discuss our findings in the context of recalculated ¹⁰Be data from elsewhere in the tropical Andes and explore tropical Pacific SST anomalies as potential drivers of tropical tropospheric temperature variability.