Lake Winnipeg, Eastern Canadian Prairies 1000-year Record of Dry Conditions From Oxygen and Carbon Isotope Data Buhay, W.M.; Simpson, S.; Thorleifson, H.; Lewis, M.; King, J.; Telka, A.; Wilkinson, P.; Babb, J.; Timsic, S.; Bailey, D. Buhay, W.M. Simpson, S. Thorleifson, H. Lewis, M. King, J. Telka, A. Wilkinson, P. Babb, J. Timsic, S. Bailey, D. earth science/paleoclimate/paleolimnology (delta 13C,organic matter,null,per mil VPDB,null,paleolimnology,null,null,N,carbon isotopes from sediment organic matter;organic matter sediment samples sieved at 500 um #) earth science/paleoclimate/paleolimnology (depth,null,null,centimeter,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (age,null,null,year Common Era,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (delta 18O,cellulose,null,per mil VSMOW,null,paleolimnology,null,null,N,oxygen isotopes from cellulose;sediment-extracted cellulose) earth science/paleoclimate/paleolimnology (age,null,null,calendar year before present,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (Lake Winnipeg>LATITUDE 50.57>LONGITUDE -96.83) A short sediment core (162 cm), covering the period AD 920–1999, was sampled from the south basin of Lake Winnipeg for a suite of multi-proxy analyses leading towards a detailed characterisation of the recent millennial lake environment and hydroclimate of southern Manitoba, Canada. Information on the frequency and duration of major dry periods in southern Manitoba, in light of the changes that are likely to occur as a result of an increasingly warming atmosphere, is of specific interest in this study. Intervals of relatively enriched lake sediment cellulose oxygen isotope values (δ18Ocellulose) were found to occur from AD 1180 to 1230 (error range: AD 1104–1231 to 1160–1280), 1610–1640 (error range: AD 1571–1634 to 1603–1662), 1670–1720 (error range: AD 1643–1697 to 1692–1738) and 1750–1780 (error range: AD 1724–1766 to 1756–1794). Regional water balance, inferred from calculated Lake Winnipeg water oxygen isotope values (δ18Oinf-lw), suggest that the ratio of lake evaporation to catchment input may have been 25–40% higher during these isotopically distinct periods. Associated with the enriched δ18Ocellulose intervals are some depleted carbon isotope values associated with more abundantly preserved sediment organic matter (δ13COM). These suggest reduced microbial oxidation of terrestrially derived organic matter and/or subdued lake productivity during periods of minimised input of nutrients from the catchment area. With reference to other corroborating evidence, it is suggested that the AD 1180–1230, 1610–1640, 1670–1720 and 1750–1780 intervals represent four distinctly drier periods (droughts) in southern Manitoba, Canada. Additionally, lower-magnitude and duration dry periods may have also occurred from 1320 to 1340 (error range: AD 1257–1363), 1530–1540 (error range: AD 1490–1565 to 1498–1572) and 1570–1580 (error range: AD 1531–1599 to 1539–1606). NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Buhay, W.M. Investigator : Simpson, S. Investigator : Thorleifson, H. Investigator : Lewis, M. Investigator : King, J. Investigator : Telka, A. Investigator : Wilkinson, P. Investigator : Babb, J. Investigator : Timsic, S. Investigator : Bailey, D. 2017-11-13 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/23087 https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/noaa-templates/data-version-1.0.0/Winnipeg.Buhay.2009.txt https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/data-version-1.0.0/Winnipeg.Buhay.2009.lpd https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/noaa-templates/data-version-1.0.0/Winnipeg.Buhay.2009.txt https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/data-version-1.0.0/Winnipeg.Buhay.2009.lpd English https://www.ncdc.noaa.gov/paleo/study/23087 https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/noaa-templates/data-version-1.0.0/Winnipeg.Buhay.2009.txt https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/data-version-1.0.0/Winnipeg.Buhay.2009.lpd Buhay, William Mark; Simpson, Shawna; Thorleifson, Harvey; Lewis, Mike; King, John; Telka, Alice; Wilkinson, Paul; Babb, Jeff; Timsic, Sandra; Bailey, Dan2009A 1000-year record of dry conditions in the eastern Canadian prairies reconstructed from oxygen and carbon isotope measurements on Lake Winnipeg sediment organicsJournal of Quaternary Science24510.1002/jqs.1293 START YEAR: 993 cal yr BP * END YEAR: -48 cal yr BP -96.83 50.57 -96.83 50.57