Variation of Solar Radiation

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Motivation Theory Sources Methods Conclusion ?

Variation of Solar Radiation

10 Be in Stalagmites

Thomas Kuster, André Welti

Department of Environmental Sciences ETH Zürich

Advanced Geochemistry, 2 February 2007

Thomas Kuster, André Welti Variation of Solar Radiation

Outline

1 Motivation

2 Theoretical Background Influence of Cosmic Ray Beryllium Isotops

3 Sources Where Speleothem

4 Methods

5 Conclusion

6 Questions

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Hypothesis

Temple in Tikal [Wikipedia, 2005]

Collapse of the Maya Culture Around 800 AD ^a

Because of droughts

aAnno Domini, latin for "in the year of the lord"

Hypothesis

The collapse of the maya culture was at a time of high solar radiation flux, which induced droughts.

Motivation Theory Sources Methods Conclusion ? Influence of Cosmic Ray Beryllium Isotops

Influence of Cosmic Ray

Cosmic Ray

The biggest part of cosmics ray comes from the sun.

The Flux of radiation depends on:

Variations in earth’s orbit (Milankovi´c):

cycles of approximately 23 000, 41 000 and 100 000 years Fluctuations in the solar activity:

cycles of approximately 11 and 80–90 years

Influence Climate

Life on earth (e. g. collapse of the maya culture)

Different formation ratios of isotopes

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Cycles

[Earth Observatory (NASA), 2007]

Milankovi´c cycles

≈ 23 000 a

≈ 41 000 a

≈ 100 000 a

Cycles

10 10 Be und kosmische Strahlung Be und kosmische Strahlung

Sonnenflecken Sonnenflecken Konzentration von Konzentration von ¹⁰¹⁰BeBe

[Schüssler, 2001]

Sunspots

Fluctuations in the solar activity,

cycles of

approximately 11

and 80–90 years

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Influence of Cosmic Ray

Cosmic Ray

The biggest part of cosmics ray comes from the sun.

The Flux of radiation depends on:

Variations in earth’s orbit (Milankovi´c):

cycles of approximately 23 000, 41 000 and 100 000 years Fluctuations in the solar activity:

cycles of approximately 11 and 80–90 years

Influence Climate

Life on earth (e. g. collapse of the maya culture) Different formation ratios of isotopes

Forming of ¹⁰ Be

Reactions

Froming of ¹⁰ Be with neutrons (n) and protons (p) from cosmic ray.

14 N + n −→ ¹⁰ Be + 3p + 2n

14 N + p −→ ¹⁰ Be + 4p + 1n

16 O + n −→ ¹⁰ Be + 4p + 3n

16 O + p −→ ¹⁰ Be + 5p + 2n

Where

Upper atmosphere (30% in the troposphere and the the rest above).

Sediments out with aerosols.

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Motivation Theory Sources Methods Conclusion ? Where Speleothem

Sources of Beryllium with Time Resolution

Different Sources ice cores sediments speleothems

Speleothem

From the Greek for "cave deposit".

German: Speläotheme (sekundäre Mineralablagerungen in Höhlen)

Stalactites and Stalagmites

Dambovicioara Cave [ICI, Bucharest, 1999]

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Memory hook

English

Stalagmites grow from the ground, stalactites grow from the ceiling

German

Stalagmiten haben schon viel „mitgemacht“ sind daher „müde“

und deswegen am Boden, während Stalaktiten tropfen und an der Decke hängen.

Children: Die Stalaktiten kommen von der „T“ecke, und die Stalagmiten wachsen mit dir mit.

Adult: Die Mi(e)ten steigen und die (Stalak)tit(t)en hängen.

French

La Stalagmite monte, la stalagtite tombe

Stalagmites

Why Stalagmites

Available on all continents

In the region of the maya culture too

Influence of the terrestrial magnetic field is included

Stalactites could be hollow

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Methods

Separation

Extract the element by several seperation steps.

Dating

uranium series ( ²³⁸ U −→ ^α ²³⁴ Th ^β

−

−→ ²³⁴ Pa ^β

−

−→ ²³⁴ U)

δ Be measurements

10 Be Tandem Accelerator Mass Spectrometry (T-AMS) because of the extremly low concentration of this isotope

9 Be Inductively Coupled Plasma Mass Spectrometry (ICP-MS) or

Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES)

Van de Graaff EN tandem type accelerator

ETH Hönggerberg (HPK) [Institute of Particle Physics, 2002]

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Methods

Separation

Extract the element by several seperation steps.

Dating

uranium series ( ²³⁸ U −→ ^α ²³⁴ Th ^β

−

−→ ²³⁴ Pa ^β

−

−→ ²³⁴ U)

δ Be measurements

10 Be Tandem Accelerator Mass Spectrometry (T-AMS) because of the extremly low concentration of this isotope

9 Be Inductively Coupled Plasma Mass Spectrometry (ICP-MS) or

Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES)

Conclusion

Hypothesis

The collapse of the maya culture was at a time of high solar radiation flux, which induced droughts.

Test of the Hypothesis

If there is no maximum of the δ ¹⁰ Be when the maya culture

collapsed then the hypothesis must be wrong.

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Questions

[Slemko, 2003]

Appendix List of figures Bibliography Sources

List of figures I

Earth Observatory (NASA).

On The Shoulders of Giants, Milutin Milankovitch (1879–1958), 2007.

ICI, Bucharest.

Dambovicioara Cave, December 1999.

Institute of Particle Physics.

Ion Beam Physics, October 2002.

Manfred Schüssler.

Das Magnetfeld der Sonne und die globale Erwärmung:

Steuert die Sonne das Erdklima?, December 2001.

Sarah Slemko.

Fragen, 2003.

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List of figures II

Wikipedia.

Temple in Tikal, February 2005.

Bibliography I

Peter Foukal, Gerald North, and Tom Wigley.

A Stellar View on Solar Variations and Climate.

Science, 306(5693):68–69, October 2004.

Peter Foukal, C. Fröhlich, H. Spruit, and T. M. L. Wigley.

Variations in solar luminosity and their effect on the Earth’s climate.

Nature, 443(05072):161–166, September 2006.

Gerald H. Haug and Larry C. Peterson.

150 Jahre Trockenheit.

Spektrum der Wissenschaft, January 2006.

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Bibliography II

Gerald H. Haug, Detlef Günther, Larry C. Peterson, Daniel M. Sigman, Konrad A. Hughen, and Beat Aeschlimann.

Climate and the Collapse of Maya Civilization.

Science, 299(5631):1731–1735, March 2003.

Rick Hershberger.

Writing the Scientific Research Proposal, March 1997.

David A. Hodell, Mark Brenner, Jason H. Curtis, and Thomas Guilderson.

Solar Forcing of Drought Frequency in the Maya Lowlands.

Science, 292(5520):1367–1370, May 2001.

Bibliography III

David A. Hodell, Mark Brenner, and Jason H. Curtis.

Terminal Classic drought in the northern Maya lowlands inferred from multiple sediment cores in Lake

Chichancanab (Mexico).

Quanternary Science Reviews, 24:1413–1427, July 2005.

Stefand Alphons Walter Jacob.

Beschleunigermassenspektrometrie (AMS).

PhD thesis, ETH, Zürich, 2001.

Katarina Lundblad.

Studies on Tropical Palaeo-variation in Climate and Cosmic

Ray Influx: Geochemical data from stalagmites collected in

Tanzania and northern South Africa.

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Bibliography IV

PhD thesis, Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology, 2006.

Maura V. Vonmoos.

Rekonstruktion der solaren Aktivität im Holozän mittels Beryllium-10 im GRIP Eisbohrkern.

Variation of Solar Radiation