Holocene Hydrological Variation in the Lake Titicaca Drainage Basin
by
Sheri Fritz
Department of Geosciences, University of Nebraska
Coauthors: Paul Baker (Duke University, USA), Erik Ekdahl, Lora Stevens (University of Nebraska, USA), Kirstin Coley (University of London, UK)and Catherine Rigsby (East Carolina University, USA)

High-resolution analyses of a suite of biological (diatoms, algal spores, pollen) and geochemical (inorganic and organic carbon, biogenic silica, isotopes) variables have been completed for Holocene age sediments from several sites in Lake Titicaca, as well as for two smaller lakes (Lago Lagunillas and Lago Umayo) within the Lake Titicaca drainage basin. Here we compare multiple proxies at individual sites and evaluate their differential behavior as indicators of hydrologic change. We then use the records from the three lake systems to derive the dominant frequencies of variation and to generate a picture of Holocene hydrological change as it operates at multiple scales. At orbital time scales, substantial lake-level lowering during the mid-Holocene indicates major moisture deficits, followed by rising levels and moisture after ~5000 years ago. Superimposed on these orbital patterns are higher frequency variations, which include a quasi-1400-year variation that is in phase with the Bond IRD cycles in the North Atlantic and suggests a linking of Atlantic sea-surface temperatures and precipitation variation on the Altiplano. Multi-decadal fluctuations in lake level and inferred precipitation also are apparent in the records and suggest modes of variation in regional hydrology operating at shorter time scales and that may be related to observed oscillatory modes in the Earth’s climate system

Date received: November 15, 2004

Copyright © 2004 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caod-17.