A 130 ka reconstruction of rainfall on the Bolivian Altiplano

摘要: New efforts to link climate reconstructions from shoreline deposits and sediment cores yield an improved more detailed lake history the Bolivian Altiplano. On Southern Altiplano, 10 oscillations have been identified this new unified chronology, each coincident with North Atlantic cold events such as Heinrich Events H5, H2, H1, Younger Dryas. By coupling a hydrologic budget model we are able evaluate precipitation variability on Altiplano over last 130 ka. These modeling underscore relative aridity of during rare small cycles occurring between 80 20 ka, when colder temperatures combined little or no change in rainfall produced smaller paleolakes. Relative ka contrasts immense Tauca cycle (18.1–14.1 ka), which was six times larger than modern Lake Titicaca coincided Event 1. This paleolake record reveals strong central Andean sea-surface temperature gradients late Pleistocene, even though today is driven mostly by Pacific anomalies associated El Nino/Southern Oscillation. However, not all appear result expansions, most conspicuously global interval Amazon Basin were relatively arid.