Salar de Uyuni, Bolivia Drill Hole 50KYR Natural Gamma Radiation Baker, P.A.; Rigsby, C.A.; Seltzer, G.O.; Fritz, S.C.; Lowenstein, T.K.; Bacher, N.; Veliz, Y Baker, P.A. Rigsby, C.A. Seltzer, G.O. Fritz, S.C. Lowenstein, T.K. Bacher, N. Veliz, Y PAGES 2k Network PAGES LOTRED SA2k hydrology earth science/paleoclimate/paleolimnology (depth,null,null,meter,null,paleolimnology,corrected,null,N,null) earth science/paleoclimate/paleolimnology (depth,null,null,meter,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (gamma radiation,sediment,null,count per second,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (age,null,null,calendar year before present,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (Salar de Uyuni>LATITUDE -20.25>LONGITUDE -67.5) Tropical South America is one of the three main centres of the global, zonal overturning circulation of the equatorial atmosphere (generally termed the 'Walker' circulation). Although this area plays a key role in global climate cycles, little is known about South American climate history. Here we describe sediment cores and down-hole logging results of deep drilling in the Salar de Uyuni, on the Bolivian Altiplano, located in the tropical Andes. We demonstrate that during the past 50,000 years the Altiplano underwent important changes in effective moisture at both orbital (20,000-year) and millennial timescales. Long-duration wet periods, such as the Last Glacial Maximum marked in the drill core by continuous deposition of lacustrine sediments appear to have occurred in phase with summer insolation maxima produced by the Earth's precessional cycle. Short-duration, millennial events correlate well with North Atlantic cold events, including Heinrich events 1 and 2, as well as the Younger Dryas episode. At both millennial and orbital timescales, cold sea surface temperatures in the high-latitude North Atlantic were coeval with wet conditions in tropical South America, suggesting a common forcing. STUDY NOTES: Natural gamma radiation (counts per second) from a drill hole in the Salar de Uyuni, Bolivia, salt flat, used as a proxy for Lake Level over the past 50,000 years. Mud units contain abundant radiogenic K, U, and Th, whereas salt units are largely nonradioactive. Note: Adjusted depths match gamma log data with the equivalent depths in the sediment core - see Fritz et al. 2004 for additional information. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Baker, P.A. Investigator : Rigsby, C.A. Investigator : Seltzer, G.O. Investigator : Fritz, S.C. Investigator : Lowenstein, T.K. Investigator : Bacher, N. Investigator : Veliz, Y 2010-08-26 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/9952 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/southamerica/bolivia/salar-de-uyuni2001.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/southamerica/bolivia/salar-de-uyuni2001.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/southamerica/bolivia/salar-de-uyuni2001.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/southamerica/bolivia/salar-de-uyuni2001.xls English https://www.ncdc.noaa.gov/paleo/study/9952 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/southamerica/bolivia/salar-de-uyuni2001.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/southamerica/bolivia/salar-de-uyuni2001.xls Baker, P.A., C.A. Rigsby, G.O. Seltzer, S.C. Fritz, T. Lowenstein, N. Bacher, and Y. Veliz. 2001. Tropical climate changes at millennial and orbital timescales revealed by deep drilling on the South American Altiplano. Nature 409: 698-701. START YEAR: 49959 cal yr BP * END YEAR: 0 cal yr BP -67.5 -20.25 -67.5 -20.25