WWW.DISSERTATION.XLIBX.INFO
FREE ELECTRONIC LIBRARY - Dissertations, online materials
 
<< HOME
CONTACTS



Pages:   || 2 | 3 | 4 | 5 |   ...   | 18 |

«by Sarah Miranda Aarons A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Geology) in the ...»

-- [ Page 1 ] --

Evidence of Regional and Global Climate Change in the Mineral Aerosol

(Dust) Record from Ice Cores Through the Anthropocene and Pleistocene

by

Sarah Miranda Aarons

A dissertation submitted in partial fulfillment

of the requirements for the degree of

Doctor of Philosophy

(Geology)

in the University of Michigan

Doctoral Committee:

Assistant Professor Sarah M. Aciego, Co-Chair

Professor Joel D. Blum, Co-Chair

Associate Professor Jeremy N. Bassis

Assistant Professor Rose Cory Assistant Professor Mark G. Flanner

ACKNOWLEDGMENTS

First I thank the University of Michigan, Rackham Graduate School, and the Department of Earth and Environmental Sciences for providing me with the opportunity to pursue my passion. My graduate experience would not be possible without the sponsorship and mentorship from my adviser, Dr. Sarah Aciego, who opened doors to me that allowed me to conduct fieldwork in some of the most beautiful places in the world. Her mentorship style allowed me to explore problems and research questions independently, and I know this will benefit me tremendously in the future. As Sarah’s student, it is clear that she made a concerted effort to provide opportunities and educational outreach to students from diverse backgrounds, and I am appreciative of her efforts. I would also like to thank the other members of my dissertation committee: Dr. Joel Blum, Dr.

Jeremy Bassis, Dr. Rose Cory, and Dr. Mark Flanner for their guidance and advice during my Ph.D.

I am also grateful for the support of others during my time as a graduate student.

My colleagues, Carli, Molly, Yi-Wei, Emily and Mark provided companionship and emotional support during long workdays. Carli and Molly were exceptional field mates (and future roommates) and I am so grateful for the time we spent together. Life as a graduate student can be stressful, and my lab mates were ii always there to support me when I needed it. There are many other unnamed graduate students in my cohort and I am thankful for their friendship and camaraderie.

I would like to acknowledge my Mom, Dad, sisters Miriam and Elizabeth and my remaining family members for their continuing emotional support throughout my Ph.D. work. Specifically, thank you to my dad who sparked my curiosity in the earth and taught me the power of using science to answer questions. I am grateful to my mom, who placed so much value and emphasis on the importance of obtaining an education. She taught me that education and knowledge provides empowerment, especially for underrepresented minorities. My Ph.D. degree has been a difficultjourney, but my mom is the reason I have persisted. Finally, I would like to thank Nick, who is an endless source of reassurance and comfort.

–  –  –

Acknowledgements ……………………………………………………………… ii List of Figures……………………………………………………………………… viii List of Tables…….………………………………………………………………... xi Abstract…….…….………………………………………………………………… xii Chapter

I. Introduction

1.1. Effect of Dust on climate ……………………………………... 1

1.2. Climate change in ice record ………………………………… 2

1.3. Paleo-dust record in ice cores………………………………… 3

1.4. Rare Earth, Trace Elements and Dust Provenance……....... 5

1.5. Principles of strontium and neodymium isotope geochemistry…………………………………………………………. 7

1.6. Dust provenance and Radiogenic Isotopes...………………. 8

1.7. The Horizontal ice core………………………………………… 9

1.8. Aims and motivation of this thesis……………………………. 10 1.8.1. Taylor Dome and Taylor Glacier 1.8.2. Upper Fremont Glacier

1.9. Publications resulting from this dissertation………………… 12

1.10. References……………………………………………………. 14

–  –  –

IV. Dust aerosol composition changes in East Antarctica during Glacial-Interglacial transition Abstract…………………………………………………………….. 120

4.1. Introduction…………………………………………………… 121

4.2. Regional setting……………………………………………… 123 4.2.1. Local climate effects of retreating ice shelf extent 4.2.2 Age scale of Taylor Glacier ‘horizontal ice core’

4.3. Materials and methods……………………………………… 129 4.3.1 Sample collection 4.3.2 Sample preparation and processing 4.3.3 Trace and Rare Earth Element analysis 4.3.4 Chloride ion analysis 4.3.5 Dust particle size and concentration analysis 4.3.6 Strontium and neodymium isotope analysis

4.4 Results………………………………………………………… 134 4.4.1 Trace and Rare Earth Element concentration 4.4.2 Chloride concentration 4.4.3 Dust concentration and size distribution 4.4.4 Radiogenic isotopic composition

4.5 Discussion…………………………………………………….. 145 4.5.1 Changes in dust concentrations and fluxes indicated by trace and rare earth elements 4.5.1.1 Variations in dust contributions inferred from crustal enrichment factors (EFc) 4.5.1.2 Contributions from sea salt

–  –  –





V. Conclusion: Geochemical analysis of dust record preserved in ice cores

5.1 Summary of Conclusions……………………………………... 180

5.1.1 Chapter 2: A record of dust throughout the

Anthropocene 5.1.2 Chapter 3: Characterization of dust to East Antarctica during Holocene 5.1.3 Chapter 4: A high-resolution record of dust compositional changes during a major climate transition

5.2 References……………………………………………………....184

vii LIST OF FIGURES

Figure

1.1 Schematic cross-section of ice sheet showing relative velocity, accumulation and ablation areas, ice divide, and particle flow path……………………………………………………………………………...10

1.2 Map of Taylor Dome, Taylor Glacier, and Upper Fremont Glacier.….…..11

2.1 Upper Fremont Glacier (UFG) location map with 1998 and 1991 coring sites……………………………………………………………………………..21

2.2 Schematic of dust particle size distribution as an indicator of transport distance………………………………………………………………………....24

2.3 Historical land use maps for United States during the time periods of 1700, 1800, 1900 and today………………………………………………..………..27

2.4 NOAA HYSPLIT air parcel backward trajectory model for UFG coring site……………………………………………………………………..………..30

2.5 Schematic of ice core sample preparation……………………………….....33

2.6 Ice thickness cross sections ………………………………….……………...38

2.7 Age-depth profile………………………………………………..……………..40

2.8 Dust particle size distribution of select samples of UFG ice core………...41

2.9 Dust particle size distribution …………………………

2.10 Isotope, dust concentration and trace element records………………......45

2.11 Combined radiogenic strontium and neodymium compositions of dust within UFG ice and potential source areas of dust………..……………....47

3.1 Map of Taylor Dome and surrounding area in East Antarctica…………..60

3.2 Schematic of Taylor Dome ice core sample preparation for radiogenic isotope and rare earth element analysis of insoluble and soluble portion of TYD ice core……………………………………………….………….………67 viii

3.2 Rare earth element concentrations of TYD dust in ice…………………...75

3.4 Thirty-two-thousand-year climate history of the Ross Sector of East Antarctica……………………………………………………………………….77

3.5 Radiogenic isotope compositions of Taylor Dome ice core dust and regional Potential Source Areas…..…………………………………………79

3.6 Rare earth element concentrations of Taylor Dome ice core soluble portion (full digestion) in comparison to REE concentrations in seawater……………………………………………………………………….88

3.S1 Particle size distributions of samples measured in this study…………...114

3.S2 Taylor Dome dust concentration for three different size fractions……...114

3.S3 Sodium-to-strontium ratio of samples measured in this study with respect to age………………………………………………….……………………...115

3.S4 Normalized rare earth element concentrations of TYD ice soluble and insoluble portion (full digestion) to the mean crustal abundance separated by time period………………………………………………………………..115

3.S5 Mixing model results of rare earth element concentrations of Taylor Dome sample with dust input from Ross Sea sector and Southern South America……………………………………………………………………….116

3.S6 Mixing model results of rare earth element concentrations of Taylor Dome sample with seawater and dust input…….……………………………….117

3.S7 Radiogenic isotope composition of potential source areas in the Southern Hemisphere plotted in various colors………………………………….…..118

4.1 Map of Taylor Glacier and sampling transect locations and the ‘zero age’ sample at Round Mountain……………………………………………..….125

4.2 Schematic cross section of ice sheet and ice shelf extent from Siple Dome to the Ross Ice Shelf……………………………………..………………...127

4.3 Variations in race elements Li, Rb, and Al concentration as a function of age of the ice during time period studied………………….….………….135

4.4 Variations in trace elements Mn, Sr, and As crustal enrichment factor as a function of age of the ice during time period studied………………….…136 ix

4.5 Normalized rare earth element concentrations of TG dust in ice with respect to mean crustal abundance………………………………………..138

4.6 Chloride concentration of Taylor Glacier ice from ~40-0 ka with EPICA Dome C for comparison……………………...…………………………..… 139

4.7 Dust concentration with respect to time and ratio of fine to coarse dust (RFP/CP) throughout time period studied…………………..………………..141

4.8 Radiogenic isotope composition of Taylor Glacier insoluble dust and ice throughout time……………………………………………………………....144

4.9 Radiogenic isotopic compositions of Taylor Glacier ice core dust and potential source areas……………………………………….………………145

4.10 Sodium to strontium elemental ratio of Taylor Glacier ice and a surface sample during time period studied………………………………………....147

4.11 Radiogenic isotopic compositions of dust and the ratio of fine to coarse dust (RFP/CP) …………...……………………………………….…………….154

4.S1 Particle size distributions of samples measured from Taylor Glacier......176

4.S2 Radiogenic isotope composition of potential source areas in the Southern Hemisphere plotted in various colors ……………………………………...177

x LIST OF TABLES

Table

2.1 Trace element enrichment factors…………………………………………...46

2.2 Radiogenic isotopic compositions of UFG dust………………………...…..49

3.1 Radiogenic isotope compositions of Taylor Dome ice samples……..…...70

3.S1 Dust particle concentration of Taylor Dome ice core with respect to dust particle diameter and age.…………………………………………………. 103

3.S2 Rare earth element concentrations of traditional acid leach and full acid digestion Taylor Dome ice core samples………………………………...104

3.S3 Sodium and strontium trace element concentrations of Taylor Dome ice

3.S4 Detailed sample information of Ross Sea Sector potential source area dust…………………………………………………………………………. 108

4.1 Radiogenic isotope compositions of dust from Taylor Glacier ice samples………………………………………………………………………143

4.S1 Rare earth element concentrations of Taylor Glacier samples and approximate ages……………………………………………….…………..165

4.S2 Rare earth element concentrations of Taylor Glacier samples and approximate ages…………………………………………..……………….170

4.S3 Chloride concentrations of Taylor Glacier ice samples and approximate ages……………………………………………..……………..……………..173

4.S4 Dust concentrations and size distribution data for Taylor Glacier ice and approximate ages………………………………………………………..….174

4.S5 Radiogenic isotope compositions of soluble portion of Taylor Glacier ice samples ……………………………………………………………..……….175

–  –  –



Pages:   || 2 | 3 | 4 | 5 |   ...   | 18 |


Similar works:

«Concepts and Meaning in Medieval Philosophy By Stephen Read Abstract: In Concepts, Fodor identifies five non-negotiable constraints on any theory of concepts. These theses were all shared by the standard medieval theories of concepts. However, those theories were cognitivist, in contrast with Fodor’s: concepts are definitions, a form of natural knowledge. The medieval theories were formed under two influences, from Aristotle by way of Boethius, and from Augustine. The tension between them...»

«Ghent University Faculty of Arts and Philosophy Academic year 2015/2016 Ethnicity, Voting and the Promises of the Independence Movement in Tanzania: The Case of the 2010 General Elections in Mwanza Mrisho Mbegu Malipula Dissertation presented in the fulfilment of the requirements for the Degree of Doctor of Comparative Science of Culture Promoter: Prof. Dr. Koenraad Stroeken i ACKNOWLEDGEMENT This dissertation is the result of research work I embarked upon since December 2011 when I secured...»

«THERMOMECHANICAL FATIGUE CRACK FORMATION IN A SINGLE CRYSTAL NI-BASE SUPERALLOY A Dissertation Presented to The Academic Faculty By Robert Lewis Amaro In Partial Fulfillment Of the Requirements for the Degree Doctor of Philosophy in the George W. Woodruff School of Mechanical Engineering Georgia Institute of Technology December, 2010 THERMOMECHANICAL FATIGUE CRACK FORMATION IN A SINGLE CRYSTAL NI-BASE SUPERALLOY Approved by: Dr. Stephen D. Antolovich, Co-Advisor Dr. Richard W. Neu, Co-Advisor...»

«Information Hazards: A Typology of Potential Harms from Knowledge Nick Bostrom Faculty of Philosophy & Oxford Martin School Oxford University [Published in Review of Contemporary Philosophy, Vol. 10 (2011): pp. 44-79] www.nickbostrom.com Abstract Information hazards are risks that arise from the dissemination or the potential dissemination of true information that may cause harm or enable some agent to cause harm. Such hazards are often subtler than direct physical threats, and, as a...»

«Parametric Optimization of Taper Cutting Process using Wire Electrical Discharge Machining (WEDM) A THESIS SUBMITTED IN FULFILLMENT OF THE REQUIREMENT FOR THE AWARD OF THE DEGREE OF Doctor of Philosophy IN MECHANICAL ENGINEERING BY Bijaya Bijeta Nayak (Roll No. 512ME124) Department of Mechanical Engineering National Institute of Technology, Rourkela 769008, India September–2015 NATIONAL INSTITUTE OF TECHNOLOGY ROURKELA-769008, ODISHA, INDIA CERTIFICATE OF APPROVAL This to certify that the...»

«The New Zealand Dressmaker: Experiences, Practices and Contribution to Fashionability, 1940 to 1980. A thesis submitted in (partial) fulfilment of the requirements for the degree of Doctor of Philosophy Jan Hamon MA (Fashion & Textile Studies) School of Design and Architecture RMIT University July 2007 i Declaration I certify that except where due acknowledgement has been made, the work is that of the author alone; the work has not been submitted previously, in whole or in part, to qualify for...»

«A CMOS Magnetic Sensor Chip for Biomedical Applications by Peng Liu A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering – Electrical Engineering and Computer Sciences in the GRADUATE DIVISION of the UNIVERSITY OF CALIFORNIA, BERKELEY Committee in charge: Professor Bernhard E. Boser, Chair Professor Seth Sanders Professor Yuri Suzuki Spring 2012 A CMOS Magnetic Sensor Chip for Biomedical Applications Copyright © 2012 by...»

«Energy Efficiency in Hybrid Mobile and Wireless Networks Ziaul Haq Abbas Energy Efficiency in Hybrid Mobile and Wireless Networks A Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Philosophiae Doctor (PhD) in Information and Communication Technology Department of Information and Communication Technology Faculty of Engineering and Science University of Agder 2012 iii Doctoral Dissertation at the University of Agder 49 ISBN: 978-82-7117-712-6 ISSN: 1504-9272...»

«UNIVERSITY OF CALIFORNIA, SAN DIEGO Efficient Thermal Management for Multiprocessor Systems A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Computer Science and Engineering by Ay¸e Kıvılcım Co¸kun s s Committee in charge: ˘ Tajana Simuni´ Rosing, Chair c Kenny C. Gross Rajesh Gupta Tara Javidi Andrew B. Kahng Dean Tullsen 2009 Copyright Ay¸e Kıvılcım Co¸kun, 2009 s s All rights reserved. The dissertation of Ay¸e...»

«Magid, Michael (2011) A validation and application of the L2 motivational self system among Chinese learners of English. PhD thesis, University of Nottingham.Access from the University of Nottingham repository: http://eprints.nottingham.ac.uk/11971/1/Magid_Thesis.pdf Copyright and reuse: The Nottingham ePrints service makes this work by researchers of the University of Nottingham available open access under the following conditions. This article is made available under the University of...»

«Timaree L Schmit, Ph.D. 215.900.2245 timaree.schmit@gmail.com http://sexwithtimaree.com Curriculum Vitae Education 2010: Widener University: Doctorate of Philosophy in Human Sexuality  Dissertation: “How Body Morphology Changes Affect Preference for Thinness and Attractiveness in Partners Among Women Attracted to Women,” December, 2010  Founding Chair of the Human Sexuality Education Student Organization  Laureate Counselor, founding executive committee member and inductee of Gamma...»

«Against Assertion1 Herman Cappelen Forthcoming in Assertion (Eds. Brown and Cappelen), Oxford 2010 Theories of assertion fall into four rough categories:2 (i) Assertions are those sayings that are governed by certain norms – the norms of assertion. (ii) Assertions are those sayings that have certain effects. (iii) Assertions are those sayings that have certain causes. (iv) Assertions are those sayings that are accompanied by certain commitments. The view defended in this paper I call it the...»





 
<<  HOME   |    CONTACTS
2016 www.dissertation.xlibx.info - Dissertations, online materials

Materials of this site are available for review, all rights belong to their respective owners.
If you do not agree with the fact that your material is placed on this site, please, email us, we will within 1-2 business days delete him.