P2C2: Holocene and Late Pleistocene Climate Change in Tropical South America Based on Speleothems from the Peruvian Andes

本项目探索利用秘鲁中部高原洞穴中的洞穴标本，制作全新世和晚更新世时期三角洲氧-18同位素的高分辨率时间序列。研究人员和他的同事们假设，时间序列将直接代表区域降水的δ氧-18，它与高原上的降水量以及南美洲夏季风（SASM）的强度和平均位置相关。该研究的具体目的是研究利用δ氧-18可能产生：i)全新世的年代际解析记录，以研究亚轨道气候变率；ii)全新世早期和晚期、末次极大冰期和末次间冰期500年年分解序列研究厄尔尼诺/南方涛动（ENSO）变率；Iii)冰川转变的50年分辨率记录，以更好地确定热带地区这一关键气候转变的性质和时间；末次冰期、末次间冰期及以后的50年分辨率气候记录。主要的更广泛的影响包括支持一名女研究生的学习，以及编写英文和西班牙文版本的秘鲁豪加波洞穴学习指南，供当地和其他地方使用。

This project explores the use of speleothems from caves in the central Peruvian Altiplano to produce high resolution time series of delta oxygen-18 isotopes over the Holocene and Late Pleistocene time periods. The researcher, and his colleagues, postulate that the time series would be a direct proxy for regional delta oxygen-18 of precipitation, which is correlative with both the amount of precipitation on the Altiplano and to the intensity and mean location of the South American Summer Monsoon (SASM).The specific aims of the research are to investigate the use of delta oxygen-18 to potentially produce: i) decadally-resolved records of the Holocene to investigate sub-orbital climate variability; ii) 500-year annually-resolved series during the early and late Holocene and the Last Glacial Maximum (LGM) and last interglacial to study El Nino/Southern Oscillation (ENSO) variability; iii) 50-year resolution records of the glacial transition to better define the nature and timing of this critical climate transition in the tropics; and iv) 50-year resolution records of climate during the last glacial period, the last interglacial period, and beyond.The primary broader impacts involve supporting a female graduate student in her studies and the development of English and Spanish language versions of a study guide for Haugapo Cave in Peru to be used locally and elsewhere.