| SPELEOTHEMS |
Dykoski et al. 2005 Dongge Cave Stalagmite Holocene and Deglacial Oxygen Isotope Data
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Dykoski, C.A.;Edwards, R.L.;Cheng, H.;Yuan, D.;Cai, Y.;Zhang, M.;Lin, Y.;Qing, J.;An, Z.;Revenaugh, J. 2005 A high-resolution,
absolute-dated Holocene and deglacial Asian monsoon record from Dongge Cave, China Earth and Planetary Science Letters Vol.
233, pp. 71- 86.
| 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: -13860 AD
End Year: 1966 AD
Data: Please Cite Data Contributors!
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Summary: We present a continuous record of the Asian monsoon over the last 16 ka
from d18O measurements of stalagmite calcite. Over 900 oxygen isotopic
measurements providing information on shifts in monsoon precipitation
are combined with a chronology from 45 precise 230Th dates. d18O and
therefore Asian monsoon intensity generally follows changes in insolation,
although changes in d18O are generally accommodated in abrupt shifts
in contrast to smoothly varying insolation, indicating that threshold
effects may be important. d18O decreased dramatically (~3 per mil) at
the start of the Holocene (~11.5 ka) and remained low for ~6 ka. Four
positive d18O events centered at 11225±97 yr BP (1.05 per mil),
10880±117 yr BP (1.15 per mil), 9165±75 yr BP (1.4 per mil),
and a double event centered at 8260±64 yr BP (1.1 per mil) and
8080±74 yr BP (1.0 per mil) punctuated this period of high monsoon
intensity. All four events correlate within error with climate changes
in Greenland ice cores. Thus, the relationship between the Asian monsoon
and the North Atlantic observed during the glacial period appears to
continue into the early Holocene. In addition, three of the four events
correlate within error with outburst events from Lake Agassiz. The decline
of monsoon intensity in the mid-late Holocene is characterized by an
abrupt positive shift in d18O which occurs at 3550±59 yr BP
(1.1 per mil in ~100 yr). In addition, the Holocene is punctuated by
numerous centennial- and multi-decadal-scale events (amplitudes
0.5 to 1 per mil) up to half the amplitude of the glacial interstadial
events seen in the last glacial period. Thus, Holocene centennial and
multi-decadal-scale monsoon variability is significant, although not as
large as glacial millennial-scale variability. The monsoon shows a strong
connection with northern South American hydrological changes related by
changes in ITCZ position. Spectral analysis of the d18O record shows
significant peaks at solar periodicities of 208 yr and 86 yr suggesting
variation is influenced by solar forcing. However, there are numerous
other significant peaks including peaks at El Nino frequencies
(observed for high-resolution portions of the record between 8110 and
8250 yr) which suggest that changes in oceanic and atmospheric
circulation patterns in addition to those forced by solar changes
are important in controlling Holocene monsoon climate. In addition,
for this high-resolution portion, we observe a distinctive biennial
oscillation of the Asian monsoon, which has been associated with
the Tropospheric Biennial Oscillation (TBO).
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Complete XML Record: noaa-cave-5441
(Last Revised: 2007-10-18 )
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