Climate and Glacier Variability During Past Centuries in the North and South Patagonian Andes of Argentina

Climate and Glacier Variability during Past Centuries in the North and South Patagonian Andes of Argentina (Spine Title: Recent Climate and Glacier Changes in the Patagonian Andes) (Thesis Format: Integrated-Article) by Mariano H. Masiokas Graduate Program in Geography (Environmental Science) Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Faculty of Graduate Studies The University of Western Ontario London, Ontario, Canada January, 2008 © Mariano H. Masiokas 2008 Library and Bibliotheque et 1*1 Archives Canada Archives Canada Published Heritage Direction du Branch Patrimoine de I'edition 395 Wellington Street 395, rue Wellington Ottawa ON K1A0N4 Ottawa ON K1A0N4 Canada Canada Your file Votre reference ISBN: 978-0-494-39303-1 Our file Notre reference ISBN: 978-0-494-39303-1 NOTICE: AVIS: The author has granted a non L'auteur a accorde une licence non exclusive exclusive license allowing Library permettant a la Bibliotheque et Archives and Archives Canada to reproduce, Canada de reproduire, publier, archiver, publish, archive, preserve, conserve, sauvegarder, conserver, transmettre au public communicate to the public by par telecommunication ou par Plntemet, prefer, telecommunication or on the Internet, distribuer et vendre des theses partout dans loan, distribute and sell theses le monde, a des fins commerciales ou autres, worldwide, for commercial or non sur support microforme, papier, electronique commercial purposes, in microform, et/ou autres formats. paper, electronic and/or any other formats. The author retains copyright L'auteur conserve la propriete du droit d'auteur ownership and moral rights in et des droits moraux qui protege cette these. this thesis. Neither the thesis Ni la these ni des extraits substantiels de nor substantial extracts from it celle-ci ne doivent etre imprimes ou autrement may be printed or otherwise reproduits sans son autorisation. reproduced without the author's permission. In compliance with the Canadian Conformement a la loi canadienne Privacy Act some supporting sur la protection de la vie privee, forms may have been removed quelques formulaires secondaires from this thesis. ont ete enleves de cette these. While these forms may be included Bien que ces formulaires in the document page count, aient inclus dans la pagination, their removal does not represent il n'y aura aucun contenu manquant. any loss of content from the thesis. Canada The University of Western Ontario Faculty of Graduate Studies Certificate of Examination Chief Advisor Examining Board Dr. Brian H. Luckman Dr. Chris Smart Advisory Committee Dr. Katrina Moser Dr. James Voogt Dr. Stephen Hicock Dr. Stephen Hicock Dr. Greg Wiles The thesis by Mariano H. Masiokas entitled: Climate and glacier variability during past centuries in the north and south Patagonian Andes of Argentina is accepted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Date Chairman of Examining Board u Abstract and Keywords Updated instrumental hydro-climatic data, tree rings and glacier records from southern South America were used to document the main spatial and temporal patterns of climate and glacier variability across the Patagonian Andes over the past few centuries. Analyses of instrumental records identified four well defined regional patterns with distinct modes of variability. The south Patagonian region has warmed significantly during the 20 century and experienced a concurrent, widespread glacier mass loss. Recent glacier recession is also documented throughout the north Patagonian Andes using repeat photography. Although the gridded temperature data in this region show significant warming, improved homogenized temperature records indicate an overall negative trend. Strong negative trends also occur in regional precipitation and streamflow records. A simple climate-based "glacier mass balance" proxy series was developed to overcome the lack of local, direct mass balance measurements. This series shows a long term negative trend between 1912 and 2002 which is concordant with the widespread glacier recession. Dendrogeomorphic techniques were used to develop detailed Little Ice Age (LIA) glacier chronologies for the past few centuries at the Tronador and Fitz Roy-Lago del Desierto areas in the north and south Patagonian Andes. Trees directly affected by glacier activity at Tronador indicate two main LIA advances culminating in the early-mid 1600s and 1800s followed by several readvances. A hitherto unknown glacier advance was identified and calendar dated to ca. 450 AD. In the southern area the main LIA event th probably culminated during the early 17 century, but additional, relatively synchronous advances occurred in the early 1700s and late 1800s-early 1900s. Well-replicated tree- ring records from NW Patagonia were used to develop an annually-resolved "glacier mass balance" proxy series over the past 520 years that partially validates the glacier chronology from the Tronador area. This reconstructed proxy record, viewed cumulatively, shows a noticeable negative trend after the late 1500s and extended intervals of overall "positive" mass balance conditions that roughly precede the two main LIA advances in this region. These results highlight the great potential for future research in this region but several limitations associated with the basic data and/or the methodologies used still need to be addressed. in Keywords: Southern South America, Patagonian Andes, instrumental hydro-climatic data, tree-ring records, glacier fluctuations, Little Ice Age, dendroglaciology, glacier mass balance estimates. IV Statement on Co-Authorship Chapters 2-6 and Appendix 1 were written as stand-alone manuscripts intended for publication. Chapter 3 and Appendix 1 have been published and Chapter 4 accepted for publication. I am the first author in all cases but several co-authors assisted to a variable extent in the preparation of these manuscripts. The specific contribution of each co author is detailed below. A list of co-authors and the publication information is also provided at the beginning of the appropriate chapters. I wrote all the papers and except for the analysis of satellite images in Chapter 4 (see below) I also conducted all the data analysis and preparation of figures and tables. With some assistance from co-authors I gathered all hydro-climatic data for Chapters 2, 3 and 6, analyzed and collected or participated in the collection of most tree-ring samples used in Chapters 4 and 5, and collaborated in the collection of some of the tree-ring samples used in Chapter 6. My supervisor Dr. Brian H. Luckman is co-author of all the manuscripts. Dr. Luckman assisted with the organization and structure of the research and papers, providing useful suggestions regarding the analysis of data, the interpretation of results and the overall presentation of figures and tables. He was also crucial editing the text to improve readability. Dr. Ricardo Villalba of IANIGLA-CONICET1 is also a co-author of all the manuscripts. He was critical during the planning stages of the research and manuscripts and subsequently provided useful suggestions regarding data analysis and interpretation of results. He collected or assisted in the collection of most of the tree-ring data used throughout this thesis and provided access to a large proportion of the climatic data analyzed in Chapters 2, 3 and 6. 1 Institute Argentino de Nivologia, Glaciologia y Ciencias Ambientales, Consejo Nacional de Investigaciones Cientificas y Tecnicas, Mendoza, Argentina. v Dr. Petr Stepanek of the Czech Hydrometeorological Institute is co-author of Chapters 2 and 3. He allowed unrestricted access to his computer programs that permitted a thorough analysis of the relative homogeneity of the climatic data. He also provided useful suggestions during the preparation of these manuscripts. Drs. Steven A. Mauget of the U.S. Department of Agriculture-Agricultural Research Service and Richard L. Branham of IANIGLA-CONICET are co-authors in Chapter 2. Dr. Mauget provided the source code for the testing algorithm that identifies intra- to multi-decadal modes of variability in time series whereas Dr. Branham facilitated its implementation in a PC Windows environment. Both co-authors provided useful discussions regarding the interpretation of this methodology. Silvia Delgado of IANIGLA-CONICET is a co-author in Chapters 3 and 4. In Chapter 3 she provided useful suggestions in the interpretation of results, whereas in Chapter 4 she performed with my assistance the analyses of Landsat TM satellite data to determine glacier area changes at the study sites in the south Patagonian Andes. Marcelo E. Lascano of IANIGLA-CONICET is co-author of Chapter 3. Mr. Lascano facilitated access to updated hydro-climatic data from NW Patagonia and participated in the discussion of preliminary versions of this manuscript. Alberto Ripalta of IANIGLA-CONICET is co-author of Chapters 4 and 5. He assisted in the collection of the tree-ring samples used in these manuscripts and provided important suggestions in the field that improved the subsequent interpretation of results. Pedro Skvarca of Instituto Antartico Argentino is co-author in Chapter 4. He provided aerial photographs and useful suggestions to improve readability and interpretation of results. VI Dr. Jorge Rabassa of CADIC-CONICET2 is co-author of Chapter 5. He collected and supported the analysis of an earlier tree-ring sampling at selected sites in the forefield of Glaciar Rio Manso in the early

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