glaciology and global warming - qualitytime-esl · title: global_warming_with_animation.ppt author:...

Marianne Raynaud Copyright 2005

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Glaciology and Global Warming

What is the connection?


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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 ice Vectorial forces Movement (center to the shore) Fresh water icebergs!

Bedrock

cloud

> 4 km of ice


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An Iceberg!

Marianne Raynaud Copyright

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The Initial Project: Vostok Station

> 4 km deep

Bedrock

• Engineers drilled down to 3,270 m

• Ice core represents: 40,000 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…



An Engineering Feat


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Research!• Dating of ice

• Measurements of radioactivity • Correlation with identifiable volcanic eruptions in the past • By means of marines sediments

• Analysis • Deuterium • Ratio 18 O (isotope) to 16 O determines 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, thus climate at different periods…

• And finally…



Predictions

…over the next 100 years: The least catastrophic: + 1.5° C The most catastrophic: up to + 6° C…!


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Conclusion

• Over the past century +0.7°C • Up to +21°C by 3000 • Measures to limit production of harmful

greenhouse gases • Responsibility of both governments and citizens • Kyoto Protocol of 1997: a first step • Only way to save our planet for the generations to

come!



Acknowledgements We wish to thank the Laboratoire de

Glaciologie 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!

glaciology and global warming - qualitytime-esl · title: global_warming_with_animation.ppt author:...

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