I do not think this will be terribly informative vis a vis the Holocene or the past ten thousand years in which we have had a significant break that is still poorly described and likely unclear.
On this time scale a thousand years is too fine a resolution.
The argument for linking the cycles of the glacial age to minute variations in the solar orbit was well made in the past century. This provides better and stronger empirical support through much better resolution.
Unfortunately, the acceptance of the idea that the ice cap expands into lower latitudes caused by the failure to recognize crustal shift continues. If that proposition were to be slightly true then the Greenland cap would be covering the arctic isles at least. As it is it is all very constrained easily by the nearness of the ocean. Yet we are to suppose that sea level glaciation was possible thirty degrees further south during the Ice Age.
These solar variations are so small that while they are able to produce a signal they are not going to drop the heat input by the massive percentage needed to create lower latitude conditions.
Besides, it is impossible to have an ice age unless lots of energy is passing through the hydraulic cycle to fill the atmosphere with moisture. All the surplus moisture in the Southern Hemisphere cycles into the Antarctic and is dumped. The Gulf Stream prevents that happening in the Arctic !
So you cannot have it both ways.
Therefore if the one is impossible, then the impossibility of crustal shift must be revisited. I posted on that back in July of 2007 when I introduced the article Pleistocene nonconformity. All the difficulties disappear and all the evidence also lines up nicely.
UCSB geologist discovers pattern in Earth's long-term climate record
Contact: Gail Gallessich
805-893-7220
(Santa Barbara , Calif.
Lisiecki performed her analysis of climate by examining ocean sediment cores. These cores come from 57 locations around the world. By analyzing sediments, scientists are able to chart the Earth's climate for millions of years in the past. Lisiecki's contribution is the linking of the climate record to the history of the Earth's orbit.
It is known that the Earth's orbit around the sun changes shape every 100,000 years. The orbit becomes either more round or more elliptical at these intervals. The shape of the orbit is known as its "eccentricity." A related aspect is the 41,000-year cycle in the tilt of the Earth's axis.
Glaciation of the Earth also occurs every 100,000 years. Lisiecki found that the timing of changes in climate and eccentricity coincided. "The clear correlation between the timing of the change in orbit and the change in the Earth's climate is strong evidence of a link between the two," said Lisiecki. "It is unlikely that these events would not be related to one another."
Besides finding a link between change in the shape of the orbit and the onset of glaciation, Lisiecki found a surprising correlation. She discovered that the largest glacial cycles occurred during the weakest changes in the eccentricity of Earth's orbit –– and vice versa. She found that the stronger changes in the Earth's orbit correlated to weaker changes in climate. "This may mean that the Earth's climate has internal instability in addition to sensitivity to changes in the orbit," said Lisiecki.
She concludes that the pattern of climate change over the past million years likely involves complicated interactions between different parts of the climate system, as well as three different orbital systems. The first two orbital systems are the orbit's eccentricity, and tilt. The third is "precession," or a change in the orientation of the rotation axis.
Letter abstract
Published online: 4 April 2010 | doi:10.1038/ngeo828
Links between eccentricity forcing and the 100,000-year glacial cycle
Variations in the eccentricity (100,000 yr), obliquity (41,000 yr) and precession (23,000 yr) of Earth’s orbit have been linked to glacial–interglacial climate cycles. It is generally thought that the 100,000-yr glacial cycles of the past 800,000 yr are a result of orbital eccentricity1, 2, 3, 4. However, the eccentricity cycle produces negligible 100-kyr power in seasonal or mean annual insolation, although it does modulate the amplitude of the precession cycle. Alternatively, it has been suggested that the recent glacial cycles are driven purely by the obliquity cycle5, 6, 7. Here I use statistical analyses of insolation and the climate of the past five million years to characterize the link between eccentricity and the 100,000-yr glacial cycles. Using cross-wavelet phase analysis, I show that the relative phase of eccentricity and glacial cycles has been stable since 1.2 Myr ago, supporting the hypothesis that 100,000-yr glacial cycles are paced8, 9, 10 by eccentricity4, 11. However, I find that the time-dependent 100,000-yr power of eccentricity has been anticorrelated with that of climate since 5 Myr ago, with strong eccentricity forcing associated with weaker power in the 100,000-yr glacial cycle. I propose that the anticorrelation arises from the strong precession forcing associated with strong eccentricity forcing, which disrupts the internal climate feedbacks that drive the 100,000-yr glacial cycle. This supports the hypothesis that internally driven climate feedbacks are the source of the 100,000-yr climate variations12.
- Department of Earth Science,
Correspondence to: Lorraine
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