| 2007 GSA Denver Annual Meeting (28–31 October 2007) | |
| Paper No. 111-16 | |
| Presentation Time: 1:30 PM-5:30 PM | ||
USING THE PRECESSION METHODOLOGY TO TIME PAST GLACIAL AND INTERGLACIAL CLIMATES | ||
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SHARPE, Saxon E., Desert Rsch Institute, 2215 Raggio Pkwy, Reno, NV 89512-1095, saxon.sharpe@dri.edu
Eccentricity and precession values time interglacial and
glacial climate change as indicated by the Devils Hole, Nevada, d18O
climate change chronology. The pattern of eccentricity minima (more circular
orbit) and precession maxima in the southern hemisphere marks the timing of
change from interglacial toward glacial climate as indicated by changes in
Devils Hole d18O. Further, the pattern of eccentricity minima
followed by precession maxima in the northern hemisphere marks the termination
of glacial climate as indicated by changes in Devils Hole d18O.
This pattern shows that the last 400 k.y. cycle can be divided into
glacial, interglacial, and intermediate (transitions between glacial and
interglacial and vice versa) climate states based on the timing of precession
values and paced by eccentricity minima. If this relation is valid, then
climate is approaching a major change in state out of present-day interglacial
climate. Long lacustrine climate records show that interglacial periods often
end with a short episode that is likely warmer than the interglacial period. If
present climate corresponds to or is changing toward this short, warm episode, then
this natural warm episode could be amplified by human-driven warming over the
next few centuries. Correspondence between the termination of interglacial
events after the short warm period and the timing of maximum precession
(increased summer solar radiation) in the southern hemisphere summer with the
Devils Hole d18O record indicates that northern hemisphere
climate begins a cooling trend when heat is being added to the southern
hemisphere. This relation indicates that a link between glacial and interglacial
periods and tropical insolation may exist.
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2007 GSA Denver Annual Meeting (28–31 October 2007)
General Information for this Meeting | ||
| Presentation Handout (.pdf format, 332.0 kb) | ||
| Session No. 111--Booth# 27 Paleoclimatology/Paleoceanography (Posters) Colorado Convention Center: Exhibit Hall E/F 1:30 PM-5:30 PM, Monday, 29 October 2007 Geological Society of America Abstracts with Programs, Vol. 39, No. 6, p. 301 | ||
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