HR: 1340h
AN: PP33B-0938    [Abstracts]
TI: A High-Resolution Absolute-Dated Penultimate Glacial Monsoon Record From Hulu and Dongge Caves, China and Global Correlations of Events Surrounding Termination II
AU: Cheng, H
EM: cheng021@umn.edu
AF: Department of Geology and Geophysics University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, MN 55455 United States
AU: * Kelly, M J
EM: kell0738@umn.edu
AF: Department of Geology and Geophysics University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, MN 55455 United States
AU: Edwards, R L
EM: edwar001@umn.edu
AF: Department of Geology and Geophysics University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, MN 55455 United States
AU: Wang, Y
EM: yjwang@njnu.edu
AF: College of Geographical Science Nanjing Normal University, No. 1 Ninghai Road, Nanjing, 210097 China
AU: Kong, X
EM: kongxinggong@njnu.edu
AF: College of Geographical Science Nanjing Normal University, No. 1 Ninghai Road, Nanjing, 210097 China
AU: Ming, Y
EM: mingyanfang@njnu.edu
AF: College of Geographical Science Nanjing Normal University, No. 1 Ninghai Road, Nanjing, 210097 China
AU: Liu, W
EM: yjcai@loess.llqg.ac.cn
AF: Institute of Earth Environment Chinese Academy of Sciences, #10 Fenghui South Road, Xi'an High-Tech zone, Xi'an, 710054 China
AU: Cai, Y
EM: yjcai@loess.llqg.ac.cn
AF: Institute of Earth Environment Chinese Academy of Sciences, #10 Fenghui South Road, Xi'an High-Tech zone, Xi'an, 710054 China
AU: An, Z
EM: anzs@loess.llqg.ac.cn
AF: Institute of Earth Environment Chinese Academy of Sciences, #10 Fenghui South Road, Xi'an High-Tech zone, Xi'an, 710054 China
AU: Yuan, D
EM: dxyuan@karst.edu.cn
AF: Karst Dynamics Laboratory The Ministry of Land and Resources, 40 Qixing Road, Guilin, 710075 China
AU: Zhang, M
EM: mlzh@karst.edu.cn
AF: Karst Dynamics Laboratory The Ministry of Land and Resources, 40 Qixing Road, Guilin, 710075 China
AU: Lin, Y
EM: yslin@karst.edu.cn
AF: Karst Dynamics Laboratory The Ministry of Land and Resources, 40 Qixing Road, Guilin, 710075 China
AB: We have obtained the oxygen isotope record of three stalagmites from Hulu Cave (eastern China, $32\deg$30'N, $119\deg$10'E), offering a high-resolution absolute-dated record of Asian monsoon climate over much of the penultimate glacial period. Previously, stalagmites were analyzed from Dongge Cave (southern China, $25\deg$17'N, $108\deg$5'E), located approximately 1200 km to the southwest of Hulu Cave, providing a detailed account of $\delta$$^{18}$O variations over about the same time period (Yuan et al., 2004; Kelly et al., in review). The $\delta$$^{18}$O patterns from the Hulu and Dongge stalagmites appear to be broadly similar across the overlapping portions of the records, indicating that the stalagmites are recording a regional climate signal. Asian Monsoon climate during the penultimate glacial period follows orbitally induced insolation changes, though it is punctuated by numerous sub-orbital scale climate events. The heaviest $\delta$$^{18}$O values during the penultimate glacial period were initiated at $\sim$136 ka B.P. in both records, and are largely maintained for the next $\sim$6 kyr until abrupt strengthening of the monsoon at Monsoon Termination II. This interval is generally characterized by less variability than seen during the earlier portions of MIS 6, with $\delta$$^{18}$O values remaining around -5$\permil$. Kelly et al. (in review) have called this extended interval of time the "Weak Monsoon Interval" (WMI). The WMI, however, is punctuated by one distinct climate event, occurring at 134.5 $\pm$ 1.0 ka B.P. in the Hulu record and 133.6 $\pm$ 1.0 ka B.P. in the Dongge record. This event may correlate with warming in the Alps at 135 $\pm$ 1.2 ka B.P., as indicated by an interval of speleothem growth from Spannagel Cave (Sp\"{o}tl et al., 2002). We also demonstrate that the monsoon intensity correlates well with atmospheric CH$_{4}$ concentrations over the last two glacial cycles. In particular, we correlate the abrupt jump in CH$_{4}$ concentrations at $\sim$129 ka B.P. with our Monsoon Termination II. Based upon this correlation, we show that the full Termination II atmospheric CO$_{2}$ rise, the full Termination II Antarctic temperature rise, and the gradual portion of the CH$_{4}$ rise occur almost entirely within the Weak Monsoon Interval, an extended interval of heavy $\delta$$^{18}$O between $\sim$136 and 129 ka B.P. Due to the previously established relationship between Greenland temperatures and monsoon intensity (Wang et al. 2001), this interval likely corresponds to low Greenland temperatures. Therefore, we infer that atmospheric CO$_{2}$, Antarctic temperature, and the initial portion of the CH$_{4}$ rise preceded the increase in monsoon precipitation and warming in Greenland.
DE: 3344 Paleoclimatology
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting