The history of South American tropical precipitation for the past 25,000 years

Long sediment cores recovered from the deep portions of Lake Titicaca are u sed to reconstruct the precipitation history of tropical South America for the past 25,000 years. Lake Titicaca was a deep, fresh, and continuously ov erflowing Lake during the Last glacial stage, from before 25,000 to 15,000 calibrated years before the present (cal yr B.P.), signifying that during t he Last glacial maximum (LGM), the Altiplano of Bolivia and Peru and much o f the Amazon basin were wetter than today. The LCM in this part of the Ande s is dated at 21,000 cat yr B.P., approximately coincident with the global LGM. Maximum aridity and Lowest Lake Level occurred in the early and middle Holocene (8000 to 5500 cat yr B.P.) during a time of Low summer insolation . Today, rising Levels of Lake Titicaca and wet conditions in Amazonia are correlated with anomalously cold sea-surface temperatures in the northern e quatorial Atlantic. Likewise, during the deglacial and Holocene periods, th ere were several millennial-scale wet phases on the Altiplano and in Amazon ia that coincided with anomalously cold periods in the equatorial and high- latitude North Atlantic, such as the Younger Dryas.