| PALEOLIMNOLOGY |
Orbital forcing of continental climate during the Pleistocene: a complete astronomically tuned climatic record from Lake Baikal,
SE Siberia.
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Prokopenko, A.A.,Hinnov, L.A.,Williams, D.F.,Kuzmin, M.I. 2006 Orbital forcing of continental climate during the Pleistocene:
a complete astronomically tuned climatic record from Lake Baikal, SE Siberia. Quaternary Science Reviews Vol. 25, pp. 3431-3457.
| Data Coverage |
North: 53.696 * South: 53.696 |
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West: 108.3516 * East: 108.3516 |
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Altitude: 456 m |
Start Year: 1843200 cal yr BP * End Year: 11400 cal yr BP
Data: Please Cite Data Contributors!
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Summary: A new composite BDP-96 biogenic silica record over the entire Pleistocene
was generated by splicing BDP-96-1 and BDP-96-2 drill cores from Lake Baikal,
crosschecked against a similar record from a nearby BDP-98 drill core.
A new astronomically tuned age model is proposed based on correlating peak
biogenic silica responses with the timing of September perihelia.
This target is derived from analysis of regional climate proxy responses
during the Holocene, the last interglacial and around paleomagnetic reversals.
By resolving virtually every precessional cycle during the Pleistocene,
the new age model represents a major improvement compared with previously
reported Lake Baikal timescales. The astronomically tuned ages of the
Pleistocene paleomagnetic reversals are consistent with published dates.
The minimal tuning approach we used (precession only) has also aligned high
signal power in a narrow obliquity band, confirming the strong presence of
orbital forcing. There are also strong ca 100-ka scale cycles, but these are
not aligned with the orbital eccentricity. Despite the location of Lake
Baikal in a continental interior that is highly sensitive to insolation
forcing, the tuned biogenic silica record reveals a consistent phase
difference of -32° (ca 4 ka) relative to insolation in the obliquity band.
An inherent lag embedded in a continental proxy record, not driven by global
ice volume, is an intriguing finding. Another new observation is that long-
term changes in sedimentation rates in Lake Baikal appear to be related to
the amplitude of orbital forcing; both amplitudes and sedimentation rates
undergo significant changes during MIS 24-MIS 19 interval corresponding to
the Middle Pleistocene Transition. With potential for linking continental
and marine climato-stratigraphies, the new Baikal record serves a new
benchmark correlation target in continental Eurasia, as an alternative
to June 65°N insolation and ODP-correlated timescales.
More Info on Paleolimnology |
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Complete XML Record: noaa-lake-6068
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