Ice and sediment cores in paleoclimatology

Samuel Masoni

Quentin Impagliazzo

Luci-Lou Hebert

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INTRODUCTION

INTRODUCTION

Ice cores Sediment cores (from the lake or from the sea-floor)

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Summary

INTRODUCTION

I- Ice Cores

1) Introduction

2) History of ice core research

3) Techniques used in ice core research and dating

strategies

4) Measurements performed on the ice

5) Dating Strategy

6) A general overview of climates of the past as seen

from ice cores and related proxies:

7) What past climates are relevant to modern-day and

future climate change?

8) What more research is needed? (Four challenges)

Summary

II- Sediment Cores

1) Lake Sediments

A/ What can we learn thanks to lake sediment cores

B/ Which methods are used to determine age within the core

2) Seafloor Sediments

A/ Drilling Techniques and Repartition

B/ Cores Identification and Description

C/ Sediment composition and geographic distribution

D/ Cores Dating

E/ Advantages and disadvantages of seafloor sediment cores

CONCLUSION

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I. Ice Cores

I. Ice Cores

1) Introduction https://www.youtube.com/embed/T69_diWYbkQ?rel=0

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2) History of ice core research

I. Ice Cores

1960 : Ice core research started 1st core drilling at Camp Century in Greenland GRIP (European) and GIPS2 (US) project Antarctica (Vostok, Dome C) EPICA (European Project for Ice Coring in Antarctica)

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3) Techniques used in ice core research and dating strategies

I. Ice Cores

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3) Techniques used in ice core research and dating strategies

I. Ice Cores

DIFFICULTIES: The access to the drilling site The extreme climatic conditions The need to use a drilling fluid to prevent the hole from closing The improvement of drilling techniques

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4) Measurments performed on the ice

I. Ice Cores

Which Climate Properties Do We Have Access to ?

Temperature

Accumulation rate

Origin of the precipitation

Atmospheric composition

Other climate parameters

Volcanic and solar forcings

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5) Dating Strategy

I. Ice Cores

1) Layer counting (only for Greenland, not for Antarctica)

2) Glaciological modeling

3) Use of time markers correlation

4) Comparison with insolation changes (orbital tuning)

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6) A general overview of climates of the past as seen from the ice cores and related proxies

I. Ice Cores

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I. Ice Cores

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I. Ice Cores

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I. Ice Cores

7) What past climates are relevent to modern-day and future climate change ?

Anthropogenic perturbation

Greenhouse gas concentration never been so hight

Projected climate change compare to past climate change

Future climate change = abrupt events

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I. Ice Cores

8) What more research needed ? 4 Challenges

1) The first Challenge : Obtain an undisturbed Antarctic ice core climate record prior to 1.2 million

years ago

2) The second Challenge : Obtain an undisturbed Greenland ice core climate record covering the

integrity of the last interglacial periods

3) The third Challenge : The full description of millennial scale variability

4 ) The final Challenge : The ultra-high-resolution records of climate variability and climate

forcings spanning the past 2000 years

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II. Sediment Cores

II. Sediment cores

1) Lake sediments

A/ What can we learn thanks to lake sediments cores ?

Water level (the depth of flowing water).

Lake drying

Frost

Oxygenation

Exceptional events

Living conditions for organisms in the lake

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II. Sediment Cores

B/ Which methods are used to determine age within the core ?

Magnetic Reversal

Tephrochronology

Radiocarbon Analysis

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II. Sediment Cores

2) Seafloor Sediments

A/ Drilling Techniques and Geographical Repartition

Drilling techniques

- Difficulty : keep the sediment compact

- Different techniques for different kinds of sediments

Expedition and price:

- A common expedition

- Drilling speed : 1 m/h

- Drilling cost : 3500 $/m

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II. Sediment Cores

A/ Drilling Techniques and Geographical Repartition

Geographical repartition :

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II. Sediment Cores

B/ Cores Identification and Description

How to identify cores :

- LEG : which expedition

- SITE: where

- HOLE : which hole

- CORE: how deep

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II. Sediment Cores

B/ Cores Identification an Description

How to describe cores:

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II. Sediment Cores

C/ Sediment composition and geographic distribution Type of sediments Origin of sediments Sediment Map

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II. Sediment Cores

D/ Cores Dating

Biostratigraphy (microfossils)

Magnetic Reversal

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II. Sediment Cores

E/ Advantages and disadvantages of seafloor sediment cores

Advantages - Old enough to record the

Cenozoic sediments

- Can be dated

- Large geographical repartition

- Many types of information

Disadvantages

- High cost

- Some discontinuity

- Technical difficulties

-Low resolution

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CONCLUSION

CONCLUSION

Ice cores: - 123 000 (greenland) to 800 000 years (antartica) - Global geographic scale - High resolution Lake sediment cores: - 800 000 years - Local geographic scale - High resolution

Seafloor sediment cores : - 100 millions years - Global geographic scale - Low resolution

Reconstruct the past climates plan the futur climates

Bibliography

BIBLIOGRAPHY

Jouzel, J., & MassonDelmotte, V. (2010). Paleoclimates: what do we learn from deep ice cores?. Wiley Interdisciplinary Reviews: Climate Change, 1(5), 654-669.

Menking, K. M. (1995). Paleoclimatic Reconstruction's from Owens Lake Core OL-92, Southeastern California (No. AFRL-SR-BL-TR-98-0026). Air force research lab bolling afb dc.

Worksheet correction

Which Climate Properties Do We Have Access to ?: What are the 4 challenges in ice core research? : Which clue can give information about :

Water level (the depth of flowing water) Lake drying Frost Oxygenation Exceptional events Find the correct number :

Drilling speed : .. m/h Drilling cost : .... $/m

Which information gives :

LEG : SITE: HOLE : CORE: Examples of information listed in the table:

Will we survive ? In which conditions ?

How do you imagine our future ?

Thank you for your attention