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• Past climate changes general presentation and
  tools
• Antarctic ice cores from Byrd to Vostok
• Greenland ice cores from Camp Century to
  GRIP/GISP2
• Historical overview
• GRIP and GISP 2 rapid changes
• Dating strategy Isotope temperature
• Dating strategy
• Rapid changes in the North Atlantic
• Geographical extension of rapid cahnges
• Greenland / Anatarctica
• - The 8.2 K event
• - Ongoing projects EPICA, North GRIP and others

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GRIP and GISP2 (Central Greenland) North GRIP
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Les forages glaciaires au GROENLAND
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Below 2700 m ( 100 000 years) the two profiles
diverge due to ice flow disturbances
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The last deglaciation
d dD - 8 d18O
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D0 8
D0 12
The glacial period the Dansgaard / Oeschger
events
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Review of independent temperature estimates
Jouzel (1999) Differences largely due to
seasonality (Krinner et al., 1997 Werner et
al., 2000)
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Rapid 15N changes caused by thermal and
gravitational processes Combined use of 15N /14N
and 40Ar/ 36Ar isotopic ratios allows precise
estimate of the associated temperature
change Comparison of the ice and gas records
allow direct estimate of the firn thickness and
of the gas age/ ice age difference Direct
comparison of gas records (e.g. CH4, CO2 .)
with rapid temperature change Method also useful
for Antarctica (Cf Caillon et al., Science, 2003
who inferred the timing between CO2 and
temperature change at Termination 3
Severinghaus et al. (Nature, 1998) Severinghaus
and Brook (Science, 1999)
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North GRIP
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40Ar and 15N measurements combined with a firn
model allow precise estimates of Tsite 10C
(18 and 20), 15C (19) Landais et al. (In
preparation)
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Rapid changes in the North Atlantic
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Découverte de variations climatiques rapides
dans le passé ( 10C en quelques
décennies) Groenland, atlantique nord,
continents.. Modifications du cycle
hydrologique liées à la décharge massive
dicebergs Risque de surprise climatique dans
un climat plus chaud (apport deau douce à
travers des précipitations
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Geographical extension of rapid changes
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Lake sediments in Bavaria, Germany von
Grafensteinet al., Scienc, 2001
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French cave 200 km from the ocean Genty et al.
Nature, 2003
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Hulu Cave, East of Nanjing (China) Wang et al.
(Science, 2001)
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Dongge cave, Guizhou Province Yuan et al.
(Science, 2004)
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Greenland / Antarctica
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Corrélations Nord-Sud De 10 000 à 90 000 ans
Blunier and Brook, Science, 2001
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8.2 K event a rapid event cooling during a warm
period The day after tomorrow
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Corrélations Nord-Sud Étude de la transition
5d/5c (108 000 ans) 
Le sud se réchauffe avant le Nord sur toute la
dernière période glaciaire avec une avance de
2000 ans.
Rôle important joué par la circulation océanique
et lintensité de la circulation thermohaline
dans lhémisphère Nord.
Caillon et al., unpublished
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Raisbeck et al., Goldschmidt Conference, 2002
The 10Be peak straddles event 10, exactly as seen
in the GRIP core. This implies that, within our
ability to resolve, which we presently estimate
as 200 years, the GRIP and EPICA climaterecords
at this time are synchronous.
Interesting modelling approach of Johnsen and
Stocker, Paleoceanography, 2003
Small events / Large events ?
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Detailed water isotope profiles combined with
high resolution methane measurements should
allow to extend the record of D/O events to
previous glacials
High resolution Vostok CH4 record shows
millennial-scale variability during MIS 6 and
MIS8 (periods of 2 to 7 kyr) Delmotte et al.,
In prep , Chappellaz , Euresco, 2003
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Bender.M., Malaizé, B., Orchado, J., Sowers, T,
Jouzel, J Geophysical Monograph , 1999