Holocene Caribbean climate variability reconstructed from speleothems from western Cuba [Elektronische Ressource] / presented by Claudia Fensterer

English
181 Pages
Read an excerpt
Gain access to the library to view online
Learn more

Description

Dissertationsubmitted to theCombined Faculties for the Natural Sciences and for Mathematicsof the Ruperto-Carola University of Heidelberg, Germanyfor the degree ofDoctor of Natural Sciencespresented byDiplom-Physikerin Claudia Fenstererborn in Landau i. d. PfalzOral examination: 01.02.2011Holocene Caribbean Climate Variabilityreconstructed from Speleothems from Western CubaReferees: Prof. Dr. Augusto ManginiProf. Dr. Werner Aeschbach-HertigAbstractProxy records o er a high potential tool to investigate past climate variability. Stalagmitesas a natural archive have the advantage that they are absolutely datable and past changes in18precipitation or temperature can be highly resolved by the use of stable isotopes such as O13and C.This study uses three stalagmites from north-western Cuba to investigate past precipitationvariability in the Northern Caribbean. The records cover the whole Holocene and reveal vari-ability on several time scales. Frequency analysis initially suggest solar forcing as a main driver,but it is shown that a high correlation to Northern Atlantic sea surface temperature, namelythe Atlantic multidecadal oscillation, exist. This connection is visible on multidecadal as wellas millennial time scales, i. e. the Bond cycles. During North Atlantic cold events, such as theLittle Ice Age, the Bond events, the 8.2 ka event and the Younger Dryas, the Cuban recordsshow drier conditions.

Subjects

Informations

Published by
Published 01 January 2011
Reads 44
Language English
Document size 23 MB
Report a problem

Dissertation
submitted to the
Combined Faculties for the Natural Sciences and for Mathematics
of the Ruperto-Carola University of Heidelberg, Germany
for the degree of
Doctor of Natural Sciences
presented by
Diplom-Physikerin Claudia Fensterer
born in Landau i. d. Pfalz
Oral examination: 01.02.2011Holocene Caribbean Climate Variability
reconstructed from Speleothems from Western Cuba
Referees: Prof. Dr. Augusto Mangini
Prof. Dr. Werner Aeschbach-HertigAbstract
Proxy records o er a high potential tool to investigate past climate variability. Stalagmites
as a natural archive have the advantage that they are absolutely datable and past changes in
18precipitation or temperature can be highly resolved by the use of stable isotopes such as O
13and C.
This study uses three stalagmites from north-western Cuba to investigate past precipitation
variability in the Northern Caribbean. The records cover the whole Holocene and reveal vari-
ability on several time scales. Frequency analysis initially suggest solar forcing as a main driver,
but it is shown that a high correlation to Northern Atlantic sea surface temperature, namely
the Atlantic multidecadal oscillation, exist. This connection is visible on multidecadal as well
as millennial time scales, i. e. the Bond cycles. During North Atlantic cold events, such as the
Little Ice Age, the Bond events, the 8.2 ka event and the Younger Dryas, the Cuban records
show drier conditions. A possible driver is the strength of the thermohaline circulation. If the
thermohaline circulation is in a weaker phase, lower North Atlantic sea surface temperatures are
possibly leading to a southward Inter-tropical convergence zone and drier conditions in Cuba.
The records also reveal close connection to the Paci c El Nin~o-Southern Oscillation, which
might be driven by the Atlantic itself. This study o ers the rst continuous Holocene stalag-
mite records from the Caribbean region and further contribute to the understanding of Atlantic
and Pacic teleconnections on Northern Caribbean climate variability during the Holocene.
Zusammenfassung
Klimaarchive bieten ein gro es Potential um die nat urliche Klimavariabilitat der Vergangenheit
zu untersuchen. Stalagmiten haben den Vorteil der absoluten Datierbarkeit und vergangene
Schwankungen in Niederschlag oder Temperatur kon nen hochaufgelost durch stabile Isotope
18 13wie O und C rekonstruiert werden.
Die vorliegende Studie verwendet drei Stalagmiten aus Nord-West Kuba um die Nieder-
schlagsvariabilitat der Vergangenheit in der nordlichen Karibik zu untersuchen. Die Archive
decken das gesamte Holozan ab und zeigen eine Variabilitat auf verschiedenen Zeitskalen. Fre-
quenzanalysen deuten auf eine solare Modulation des Niederschlags hin, aber es wird gezeigt,
dass eine wichtige Verbindung zu Nord Atlantischen Meeresoberachentemperaturen, der At-
lantisch Multidekadischen Oszillation, existiert. Diese Verbindung ist sichtbar auf multideka-
dischen Zeitskalen, aber auch auf Jahrtausenden, den Bond-Zyklen. Wahrend Kal tepisoden
im Nordatlantik, wie z. B. in der kleinen Eiszeit, den Bond-Events, dem 8.2 ka-Event und der
Jungeren Dryas, zeigen die kubanischen Stalagmiten trockenere Bedingungen. Ein moglicher
Antriebsmechanismus ist die Starke der thermohalinen Zirkulation. Ist die thermohaline Zirku-
lation in einer schwac heren Phase, so sinken Nordatlantische Meeresober achentemperaturen,
was zu einer sudlichen Verschiebung der Innertropische Konvergenzzone und trockeneren Be-
dingungen in Kuba fuhrt. Die Archive deuten auch auf eine Verbindung zur Pazischen El
Nino-~ Sudlichen Oszillation hin, die moglicherweise von dem Atlantik selbst gesteuert wird. Die
vorliegende Studie stellt die ersten Stalagmiten Archive des Karibischen Raumes vor, die das
komplette Holozan abdecken und tragt zum Verstandnis der Ein usse von Atlantischen und
Pazi schen Telekonnektionen auf die Niederschlagsvariabilit at im Holozan in der nordlichen
Karibik bei.Contents
1 Introduction 1
2 Basics and Methods 5
2.1 Location, geological setting . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1.1 Dos Anas cave System . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.2 Santo Tomas cave System . . . . . . . . . . . . . . . . . . . . . . 8
2.2 Formation of Speleothems . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.3 U-series dating methods . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.3.1 U and Th geochemistry . . . . . . . . . . . . . . . . . . . . . . . 12
2.3.2 Calculation of Th/U ages . . . . . . . . . . . . . . . . . . . . . . 13
2.3.3 Correction for initial detrital contamination . . . . . . . . . . . . 15
2.3.4 MC-ICPMS and TIMS . . . . . . . . . . . . . . . . . . . . . . . . 16
2.4 Speleothems as paleoclimatic archive . . . . . . . . . . . . . . . . . . . . 18
3 Caribbean Climate Variability 23
3.1 Climatic Parameters in the Caribbean . . . . . . . . . . . . . . . . . . . 23
3.1.1 Annual precipitation pattern . . . . . . . . . . . . . . . . . . . . 23
183.1.2 O in the tropical Americas . . . . . . . . . . . . . . . . . . . . 28
3.2 Atmospheric Teleconnection Patterns in the Caribbean . . . . . . . . . . 29
3.2.1 El Nino~ Southern Oscillation . . . . . . . . . . . . . . . . . . . . 30
3.2.2 North Atlantic Oscillation . . . . . . . . . . . . . . . . . . . . . . 35
3.2.3 Atlantic Multidecadal Oscillation . . . . . . . . . . . . . . . . . . 37
3.2.4 Summary of Caribbean Teleconnection patterns . . . . . . . . . . 47
3.3 Caribbean Climate variability . . . . . . . . . . . . . . . . . . . . . . . . 48
3.3.1 Seasonal to interannual timescales . . . . . . . . . . . . . . . . . 48
183.3.2 ENSO and O . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
3.3.3 Interdecadal to multidecadal timescales . . . . . . . . . . . . . . 54
3.4 Past Climate Reconstructions . . . . . . . . . . . . . . . . . . . . . . . . 55
3.4.1 Holocene climate reconstructions . . . . . . . . . . . . . . . . . . 55
3.4.2 Holocene Climate variability in the Caribbean . . . . . . . . . . 58
4 Compilation of isotopic records, spectral investigation and cave monitoring 61
4.1 Chronology of Cuban stalagmites . . . . . . . . . . . . . . . . . . . . . . 61
4.1.1 Chronology of Cuba Grande . . . . . . . . . . . . . . . . . . . . . 614.1.2 Chronology of Cuba Pequen~o . . . . . . . . . . . . . . . . . . . . 66
4.1.3 Chronology of Cuba Medio . . . . . . . . . . . . . . . . . . . . . 72
4.2 Stable isotopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
4.2.1 Cuba Grande . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
4.2.2 Cuba Pequen~o . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
4.2.3 Cuba Medio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
4.3 Spectral analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
4.3.1 Red t, Cuba Grande . . . . . . . . . . . . . . . . . . . . . . . . . 83
4.3.2 Red t, Cuba Pequen~o . . . . . . . . . . . . . . . . . . . . . . . . 87
4.3.3 Red t, Cuba Medio . . . . . . . . . . . . . . . . . . . . . . . . . 91
4.3.4 Wavelet, Cuba Grande . . . . . . . . . . . . . . . . . . . . . . . . 95
4.3.5 Wavelet, Cuba Pequeno~ . . . . . . . . . . . . . . . . . . . . . . . 97
4.3.6 Wavelet, Cuba Medio . . . . . . . . . . . . . . . . . . . . . . . . 99
4.4 Cave Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
4.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
5 Reconstructed climate variability in the Northern Caribbean 105
5.1 Intercomparison between samples . . . . . . . . . . . . . . . . . . . . . . 105
5.2 Interpretation of isotopic records . . . . . . . . . . . . . . . . . . . . . . 108
5.3 From recent to past . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
5.4 Little Ice Age and Medieval Climate Anomaly . . . . . . . . . . . . . . . 115
5.5 Solar forcing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
5.6 Mid- to Late-Holocene variability . . . . . . . . . . . . . . . . . . . . . . 121
5.7 ENSO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
5.8 Holocene Transition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
5.9 8.2 ka event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
5.10 Younger Dryas and Preboreal . . . . . . . . . . . . . . . . . . . . . . . . 132
5.11 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
6 Conclusions and Outlook 137
7 Supplementary data 139
References 152
Acknowledgements 173