By studying past climates throughout Earth’s history, we can put current climate change into perspective. Over the past century, we have witnessed an unprecedented warming of the Earth but still do not understand how various regions, such as the tropics, will respond to global change. Through natural archives, paleoclimatology tells us the degree to which the human-induced warming taking place deviates from the past. Cave speleothems can be used to uncover historic precipitation patterns and monsoon cycles. I studied oxygen and carbon isotope records from stalagmite 22-22 collected from Huagapo Cave in the Upper Amazon Basin of the Peruvian Andes in order to investigate monsoonal signals and the presence of Heinrich— rapid cooling— events in the record. 22-22 grew from approximately 315 to 250 ka, with δ18O values ranging from -12.44 to -17.34‰ and δ13C values from -5.82 to 1.90‰. Spanning the entirety of MIS 8, 22-22 captures a glacial period and the end of the interglacial MIS 9. The isotope record tracks the South American Summer Monsoon and solar insolation. Additionally, 22-22 may reveal the presence of a rapid cooling event at the end of MIS 9. 22-22 expanded Union College’s current speleothem-based record by nearly 70,000 years and will assist in the creation of a high-resolution isotope record of the tropic region.
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