HYDROCLIMATE AND TEMPERATURE VARIABILITY IN NORTHERN MEXICO DURING MARINE ISOTOPE STAGE 5B (MIS5B)

Climate models indicate that Mexico will experience rising temperatures due to human-induced climate change, yet there is considerable uncertainty regarding the specific impact on local rainfall patterns resulting from this unprecedented warming. Records from terrestrial sources detailing fluctuations in hydroclimate during previous warm periods serve as valuable tools for assessing how climate responds to external influences and internal variability, thereby enhancing the accuracy of model predictions. However, there are few paleoclimate records that currently exist in Northern Mexico. To address this gap, our presentation will focus on a terrestrial record of hydroclimate and temperature using a stalagmite (CP-1) collected near San Luis Potosi, Mexico that formed from 86,018 yrs (±408 yrs) to 93,585 yrs (±518 yrs) during Marine Isotope Stage 5b (MIS 5b). Our climate record is based on multiple hydroclimate proxies (δ¹⁸O, δ¹³C, Mg/Ca, Sr/Ca) and novel, high-precision cave temperature measurements using nucleation-assisted fluid inclusion microthermometry. Our record shows statistically significant relationships across the following speleothem proxies: cave temperature, δ¹³C, and trace elements. When comparing our results to the δ¹⁸O record from the Northern Greenland Ice Core Project (NGRIP) during Dansgaard-Oeschger Event 22 (DO-22), CP-1 demonstrates that cave temperatures increase while trace element and δ¹³C values decrease in response to the abrupt warming period at the northern latitudes. These findings suggest that the warming in Greenland during MIS 5b likely influenced terrestrial temperatures at high and low-latitudes, as well as local moisture availability and vegetation activity above the cave site.