noaa-lake-24476 Lake Chichancanab Terminal Classic Droughts Gypsum Hydration Water Isotopes Evans, N.P.; Bauska, T.K.; Gázquez-Sánchez, F.; Brenner, M.; Curtis, J.H.; Hodell, D.A. Lake Chichancanab Terminal Classic Droughts Gypsum Hydration Water Isotopes 2018-08-02 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/24476 Investigator N.P. Evans Investigator T.K. Bauska Investigator F. Gázquez-Sánchez Investigator M. Brenner Investigator J.H. Curtis Investigator D.A. Hodell earth science paleoclimate climate reconstructions|paleolimnology sample identification,null,null,null,null,climate reconstructions|paleolimnology,null,null,C,null earth science paleoclimate paleolimnology delta 18O,gypsum,null,per mil VSMOW,null,paleolimnology,null,cavity ring-down spectroscopy,N,d18O of Gypsum Hydration Water earth science paleoclimate climate reconstructions|paleolimnology delta 17O,lake water,null,per mil VSMOW,null,climate reconstructions|paleolimnology,null,null,N,d17O of calculated mother water earth science paleoclimate instrumental delta 2H,lake water,one standard deviation,per mil VSMOW,null,instrumental,null,cavity ring-down spectroscopy,N,null earth science paleoclimate instrumental deuterium excess,lake water,null,per mil VSMOW,null,instrumental,null,cavity ring-down spectroscopy,N,null earth science paleoclimate paleolimnology age,null,95% confidence interval upper bound,year Common Era,null,paleolimnology,null,null,N,max age 95% confidence interval earth science paleoclimate paleolimnology age,null,null,year Common Era,null,paleolimnology,null,null,N,mean age earth science paleoclimate climate reconstructions|paleolimnology age,null,null,year Common Era,null,climate reconstructions|paleolimnology,null,null,N,null earth science paleoclimate instrumental delta 17O,lake water,null,per mil VSMOW,null,instrumental,null,cavity ring-down spectroscopy,N,null earth science paleoclimate paleolimnology depth,null,null,centimeter,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology age,null,95% confidence interval lower bound,year Common Era,null,paleolimnology,null,null,N,min age 95% confidence interval earth science paleoclimate paleolimnology delta 17O,gypsum,null,per mil VSMOW,null,paleolimnology,null,cavity ring-down spectroscopy,N,d17O of Gypsum Hydration Water earth science paleoclimate paleolimnology delta 2H,gypsum,null,per mil VSMOW,null,paleolimnology,null,cavity ring-down spectroscopy,N,dD of Gypsum Hydration Water earth science paleoclimate climate reconstructions|paleolimnology age,null,null,calendar year before present,null,climate reconstructions|paleolimnology,null,null,N,null earth science paleoclimate instrumental delta 17O excess,lake water,null,per meg VSMOW/SLAP,null,instrumental,null,cavity ring-down spectroscopy,N,null earth science paleoclimate instrumental longitude,null,null,degree west,null,instrumental,null,null,C,null earth science paleoclimate climate reconstructions|paleolimnology delta 17O excess,lake water,null,per meg VSMOW/SLAP,null,climate reconstructions|paleolimnology,null,null,N,O17-excess of calculated mother water; 17O-excess = ln (δ17O + 1) – 0.528 ln (δ18O + 1) earth science paleoclimate climate reconstructions|paleolimnology moisture index,null,null,dimensionless,null,climate reconstructions|paleolimnology,null,null,N,probability of drought earth science paleoclimate instrumental delta 17O,lake water,one standard deviation,per mil VSMOW,null,instrumental,null,cavity ring-down spectroscopy,N,null earth science paleoclimate instrumental delta 18O,lake water,null,per mil VSMOW,null,instrumental,null,cavity ring-down spectroscopy,N,null earth science paleoclimate instrumental notes,null,null,null,null,instrumental,null,null,C,Lake name or groundwater or rainwater earth science paleoclimate instrumental delta 2H,lake water,null,per mil VSMOW,null,instrumental,null,cavity ring-down spectroscopy,N,null earth science paleoclimate instrumental sample identification,null,null,null,null,instrumental,null,null,C,null earth science paleoclimate instrumental latitude,null,null,degree north,null,instrumental,null,null,C,null earth science paleoclimate climate reconstructions|paleolimnology depth,null,null,centimeter,null,climate reconstructions|paleolimnology,null,null,N,null earth science paleoclimate climate reconstructions|paleolimnology deuterium excess,lake water,null,per mil VSMOW,null,climate reconstructions|paleolimnology,null,null,N,d-excess of calculated mother water earth science paleoclimate climate reconstructions|paleolimnology delta 18O,lake water,null,per mil VSMOW,null,climate reconstructions|paleolimnology,null,null,N,d18O of calculated mother water earth science paleoclimate climate reconstructions|paleolimnology delta 2H,lake water,null,per mil VSMOW,null,climate reconstructions|paleolimnology,null,null,N,dD of calculated mother water earth science paleoclimate instrumental delta 18O,lake water,one standard deviation,per mil VSMOW,null,instrumental,null,cavity ring-down spectroscopy,N,null earth science paleoclimate paleolimnology oxygen isotopes earth science paleoclimate paleolimnology hydrogen isotopes geoscientificInformation -545 AD 2015 AD 2495 cal yr BP -65 cal yr BP Complete 19.855 19.855 -88.763 -88.763 Continent North America Mexico Yucatan Lake Chichancanab>LATITUDE 19.855>LONGITUDE -88.763 None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

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Boulder CO 80305-3328 USA online ASCII Nicholas P. Evans, Thomas K. Bauska, Fernando Gázquez-Sánchez, Mark Brenner, Jason H. Curtis, David A. Hodell 2018 Science 361 6401 498-501 10.1126/science.aas9871 http://science.sciencemag.org/content/361/6401/498

The demise of Lowland Classic Maya civilization during the Terminal Classic Period (~800 to 1000 CE) is a well-cited example of how past climate may have affected ancient societies. Attempts to estimate the magnitude of hydrologic change, however, have met with equivocal success because of the qualitative and indirect nature of available climate proxy data. We reconstructed the past isotopic composition (d18O, dD, 17O-excess, and d-excess) of water in Lake Chichancanab, Mexico, using a technique that involves isotopic analysis of the structurally bound water in sedimentary gypsum, which was deposited under drought conditions. The triple oxygen and hydrogen isotope data provide a direct measure of past changes in lake hydrology. We modeled the data and conclude that annual precipitation decreased between 41 and 54% (with intervals of up to 70% rainfall reduction during peak drought conditions) and that relative humidity declined by 2 to 7% compared to present-day conditions. STUDY NOTES: Gypsum hydration water oxygen (d17O, d18O) and hydrogen (dD) isotopes from Lake Chichancanab, Yucatan, Mexico, for 602-1092 CE.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/yucatan/chichancanab2018drought.txt NOAA Template File; Lake Chichancanab Inferred Probability of Drought GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/yucatan/chichancanab2018gypsum.txt NOAA Template File; Lake Chichancanab Gypsum Hydration Water Isotopes GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/yucatan/chichancanab2018water.txt NOAA Template File; Lake Chichancanab Water Isotopes GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/yucatan/chichancanab2018age.txt NOAA Template File; Lake Chichancanab BACON Age Model USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11