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QualityTime-ESL 1
Glaciology and Global Warming
What is the connection?
Marianne Raynaud Copyright 2015
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Climate Change: Today vs Tomorrow
• Average temperature today = 15° C– Without the greenhouse effect: -18°C– Over the past century: A rise of 0.7° C
• Predictions (The most catastrophic!)– A rise of up to 6° C – Over the next 100 years
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The Procedure
• Measurements?• Traces of the ancient
atmosphere?• Answer: the world’s
archives• A huge refrigerator
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Midnight Sun Over Antarctica
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Antarctica
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EPICA
European Project of Ice Coring in Antarctica
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Drilling for Ice Samples
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Antarctica Continent
Twice size of the
USA
Driest place on earth
Winds up to 320
km/h
Among the highest
mountains
Bedrock
cloud
> 4 km of ice
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The Transarctic Mountains
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The Long Trip of a Tiny Snowflake
65% of the world’s drinking water
95% of the world’s ice
Yet a desert - very little precipitation
Story of a snowflake
Compression
Entrapped air
Bubbles of air in the iceVectorial forcesMovement (center to the shore)Fresh water icebergs!
Bedrock
cloud
> 4 km of ice
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An Iceberg!
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The Initial Project: Vostok Station
> 4 km deep
Bedrock
• Engineers drilled
down to 3,270 m
• Ice core represents:
400,000 years of
compacted ice
• Ancient atmosphere Vostok-Russian base
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Ice Core Samples
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Evolution of the Atmosphere Over the Last 400,000 years
Bedrock
Present day
400,000 years ago
They have to …drill “straight” down (through moving ice)
After that they have to take the “carrots” of ice up to the surface
Carrying out an engineering feat!
A shaft: roughly 3,200 m in depth
Taking the “samples back” … “the easy part”, but first…
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An Engineering Feat
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Research
• After Dating the ice samples (Carbon 14) • Measurements of radioactivity (visible traces of nuclear bombs)
• Correlation with identifiable volcanic eruptions in the past• Study of marine sediments
• Analysis of the entrapped air • Deuterium • Ratio 18 O to 16 O (isotopes) to determine the temperature
at formation • Greenhouse gases CO2 and methane (in bubbles)
– Variation of gases over the years
– Correlation between the quantity of these greenhouse gases and the temperature
– Temperature climate prevailing at different periods of time…
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Predictions
…over the next 100 years:
The least catastrophic: + 1.5° C
The most catastrophic: up to + 6° C…!
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Conclusion
• A rise of 0.7°C over the past century • Up to 21°C by 3000 (from 15°C today)• Kyoto Protocol of 1997: a first step – several
COP* meetings since then (*Conference of Parties)
• Urgent measures needed to limit production of harmful greenhouse gases
• Responsibility of both governments and citizens • Only way to save our planet for the generations
to come!
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Acknowledgements
We wish to thank the Laboratoire deGlaciologie de Grenoble
and its researchers, who participate in
EPICA
European Project of Ice Coring in Antarctica
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Thank you for your attention!
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