| SPELEOTHEMS |
Kelly et al. 2006 Dongge Cave Stalagmite High-Resolution MIS 5/6 Oxygen Isotope Data
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Kelly, M.J.;Edwards, R.L.;Cheng, H.;Yuan, D.;Cai, Y.;Zhang, M.;Lin, Y.;An, Z. 2006 High resolution characterization of the
Asian Monsoon between 146,000 and 99,000 years B.P. from Dongge Cave, China and global correlation of events surrounding Termination
II. Palaeogeography, Palaeoclimatology, Palaeoecology Vol. 236, Issues 1-2, pp. 20-38, 23 June 2006
| Data Coverage |
North: 25.28 * South: 25.28 |
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West: 108.08 * East: 108.08 |
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Altitude: 680 m |
Start Year: -144310 AD
End Year: -97500 AD
Data: Please Cite Data Contributors!
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Summary: Speleothem samples from Hulu (eastern China, 32°30'N, 119°10'E) and
Dongge (southern China, 25°17'N, 108°5'E) Caves provide a nearly
continuous record of the Asian monsoon over the last 160 ka
[Wang et al. 2001, Yuan et al. 2004]. We have obtained higher
resolution data in the interval between ~99 and 146 ka B.P., providing
a detailed account of d18O variations over most of MIS 5 and the latter
portion of MIS 6. Precise 230Th dating has replicated the chronology of
the samples within error. The higher resolution data set confirms the
timing of Asian Monsoon Termination II (the midpoint of the negative shift
in d18O marking the onset of the Last Interglacial Asian Monsoon), placing
it at 129.0 ± 0.9 ka B.P. The bulk of this transition (~1.7 per mil) took
place within approximately 70 years, with the total range of the transition
being ~3 per mil. The most abrupt portion of the shift in d18O values
(~ 1.1 per mil) marking the end of the Last Interglacial Asian Monsoon
occurred in ~120 years, the midpoint of which is 120.7 ± 1.0 ka B.P.
The Dongge Cave monsoon d18O record over late MIS 6 exhibits a series of
sub-orbital millennial-scale climate shifts that average 1.3 per mil in
magnitude and occur on average every 1.8 ky. Abrupt shifts in d18O of up to
1 per mil also occurred throughout the Last Interglacial Asian Monsoon,
with periods at multi-decadal to centennial timescales. Similar to the
amplitude and periodicities of events found by Dykoski et al. during the
Holocene in the Dongge record, these shifts cover more than 1/2 of the
amplitude of millennial-scale and multi-centennial-scale interstadial events
during the Last Glacial Period [Wang et al. 2001] and millennial-scale and
multi-centennial-scale interstadial events during the Penultimate Glacial
Period in China (this study). Abrupt decadal to millennial-scale climate
events therefore appear to be a general feature of both glacial and
interglacial climate. We demonstrate that monsoon intensity correlates
well with atmospheric CH4 concentrations over the transition into the
Bølling-Allerød, the Bølling-Allerød, and the Younger Dryas. In addition,
we correlate an abrupt jump in CH4 concentration with Asian Monsoon
Termination II. On the basis of this correlation, we conclude that the rise
in atmospheric CO2, Antarctic warming, and the gradual portion of the rise
in CH4 around Termination II occur within our "Weak Monsoon Interval" (WMI),
an extended interval of heavy d18O between 135.5 ± 1.0 and 129.0 ± 1.0 ka B.P.,
prior to Asian Monsoon Termination II and Northern Hemisphere warming.
Antarctic warming over the millennia immediately preceding abrupt northern
warming may result from the "bipolar seesaw" mechanism. As such warming
(albeit to a smaller extent) also preceded Asian Monsoon Termination I,
the "bipolar seesaw" mechanism may play a critical role in glacial terminations.
More Info on Speleothems |
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Complete XML Record: noaa-cave-5437
(Last Revised: 2007-10-18 )
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