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Figure 6.1. Measured oxygen isotope variability at Devil's Hole (Landwehr et al., 1997).
spectrometric (TIMS) uranium series methods (Ludwig et al., 1992). The dating
has been independently verified using
231
Pa analyses. These data are unique
amongst all proxy data for past temperatures in that independent radiometric age
determination was available throughout the entire length of the core. The results
are shown in
Figure 6.1
.
Winograd et al. (1992) compared the Devil's Hole results with the Vostok,
Antarctica ice core deuterium record and the SPECMAP deduced from
d
18
O
values of planktic foraminifera. All three records show similar overall patterns
with relatively rapid shifts from full glacial to interglacial climates followed by a
gradual return to full glacial conditions. However, Winograd et al. (2002)
emphasized minor differences between the records that appear to this writer to
be in the noise. The fact that the records from widely divergent sites are similar
suggests that the Devil's Hole data represent global rather than regional trends.
However, questions have been raised about the conversion of the isotope data to
temperature (Coplen, 2007).
6.1.2 Devil's Hole data and ocean sediment data compared
When Winograd et al. published the first major Devil's Hole paper in 1992, they
pointed out that there appeared to be several discrepancies between the timing of
glacial-interglacial transitions and the predictions of the astronomical theory,
suggesting that the astronomical theory had deficiencies. Imbrie et al. (1993)
(noted defenders of the astronomical theory) immediately responded with a
rebuttal. They argued that if the Devil's Hole chronology were applied to ocean
cores, it would ''require physically implausible changes in sedimentation rate.''
They also argued that
''spectral analysis of
the Devil's Hole record shows
clear evidence of orbital
influence'' and they concluded that ''transfer of the
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