Automated Template B: Created by James Nail 2011V2.1 A multi-decadal remote sensing study on glacial change in the North Patagonia Ice field Chile By Lucy Korlekwor Tetteh A Thesis Submitted to the Faculty of Mississippi State University in Partial Fulfillment of the Requirements for the Degree of Master of Science in Geosciences in the Department of Geosciences Mississippi State, Mississippi May 2014 Copyright by Lucy Korlekwor Tetteh 2014 A multi-decadal remote sensing study on glacial change in the North Patagonia Ice field Chile By Lucy Korlekwor Tetteh Approved: ____________________________________ Shrinidhi S. Ambinakudige (Major Professor) ____________________________________ Qingmin Meng (Committee Member) ____________________________________ Padmanava Dash (Committee Member) ____________________________________ Michael E. Brown (Graduate Coordinator) ____________________________________ R. Gregory Dunaway Dean College of Arts & Sciences Name: Lucy Korlekwor Tetteh Date of Degree: May 17, 2014 Institution: Mississippi State University Major Field: Geosciences Major Professor: Shrinidhi Ambinakudige Title of Study: A multi-decadal remote sensing study on glacial change in the North Patagonia Ice field Chile Pages in Study: 91 Candidate for Degree of Master of Science Glaciers in the North Patagonian Ice Fields are temperate glaciers and can be studied to understand the dynamics of climate change. However, the ice field has been neglected in mass balance studies. In this study, multi decadal study of glacial mass balance, glacier retreat and glacial lake expansion in the North Patagonia were studied. Landsat (TM, ETM+ and 8) and ASTER images were used. San Quintin glacier experienced the highest retreat. Demarcation of glacier lakes boundaries indicated an increase in glacial lake area from 13.49 km2 to 65.06 km2 between 1979 and 2013, with an addition of 4 new glacial lakes. Nef glacier recorded the highest mass gain of 9.91±1.96 m.w.e.a.-1 and HPN-4 glacier recorded the highest mass loss of -8.9±1.96 m.w.e.a.-1. However, there is a high uncertainty in the elevation values in the DEM due to the rugged nature of the terrain and presence of the heavy snow cover. Key Words: Mass balance, Glacier, ASTER, DEM, North Patagonia, Chile DEDICATION This thesis is dedicated to the Almighty God for providing me with such a great opportunity. Secondly, to my loving family members who have offered their encouragement and support throughout my graduate study. Special thanks to my father, John Eric Tetteh; mother, Juliana Anastasia Tetteh, brothers, Henry Tetteh and Harry Tetteh and sister, Felicity Tetteh. ii ACKNOWLEDGEMENTS I greatly appreciate Dr. Shrinidhi Ambinakudige’s immense guidance in my development as a professional and assistance in my graduate research. Special thanks are also given to Dr. Qingmin Meng and Dr. Padmanava Dash who augmented this research through their countless critiques and assistance. iii TABLE OF CONTENTS DEDICATION .................................................................................................................... ii ACKNOWLEDGEMENTS ............................................................................................... iii LIST OF TABLES ............................................................................................................. vi LIST OF FIGURES .......................................................................................................... vii CHAPTER I. INTRODUCTION .............................................................................................1 Background ........................................................................................................1 Glacier mass balance measurement ...................................................................3 Glacier retreat and expansion of glacial lakes ...................................................4 Problem statement ..............................................................................................4 Study objectives .................................................................................................6 Study area: North Patagonian Ice Field .............................................................8 Research scope and limitations ........................................................................10 Thesis organization ..........................................................................................11 II. LITERATURE REVIEW ................................................................................12 Mass Balance Measurement of Glaciers ..........................................................12 Direct/in-situ method .................................................................................12 Indirect/remote sensing method .................................................................14 Digital elevation model creation and accuracy ..........................................15 Glacier studies in the NPI ................................................................................19 Glacier thinning studies in the NPI ............................................................20 Glacier retreat and lake expansion in the NPI ...........................................25 Glacial lake outburst floods .............................................................................28 III. RESEARCH METHODOLOGY.....................................................................30 Mass balance estimation of 13 glaciers in the NPI using remote sensing techniques ...............................................................................30 Dataset........................................................................................................31 ASTER .................................................................................................31 Topographic map .................................................................................32 iv Global Land Ice Measurements from Space (GLIMS) ........................32 DEM creation .............................................................................................33 Digitizing glacier boundary .......................................................................35 Elevation difference by using random points ............................................36 Uncertainty estimation ...............................................................................38 DEM accuracy test and t-tests....................................................................38 Volume change and mass balance calculation ...........................................39 Measurement of glacier retreat and expansion of glacial lakes .......................39 Dataset........................................................................................................39 Landsat .................................................................................................40 Glacier retreat measurement in the NPI ...............................................41 Expansion of glacial lakes measurements..................................................43 IV. RESULTS AND DISCUSSION ......................................................................45 Estimation of mass balance of major glaciers ..................................................45 Glacier retreat and expansion of glacial lakes .................................................53 V. CONCLUSIONS AND RECOMMENDATIONS ..........................................62 REFERENCES ..................................................................................................................65 APPENDIX A. T-TEST RESULTS FOR NON-GLACIALTED AND GLACIATED REGION FOR THE STUDY PERIOD 2007-2012 .............................73 B. T-TEST RESULTS FOR GLACIER LAKE EXPANSION AND GLACIER RETREAT FOR THE STUDY PERIOD 1979- 2013......................................................................................................90 v LIST OF TABLES 3.1 Projection information used to georeference aforementioned satellite images and topographic maps ................................................................41 4.1 Uncertainty calculation of master DEM with respect to topographic Map ........46 4.2 Descriptive statistics of non-glaciated area ........................................................46 4.3 Mass balance of glaciers from 2007 to 2012 year period...................................47 4.4 Mass balance of glacier accumulation and ablation zones. ................................49 4.5 Retreat of glaciers in the NPI .............................................................................57 4.6 Glacial lakes increase from 1979 to 2013 ..........................................................60 4.7 Glacial lakes area for 1979 and 2013 .................................................................61 vi LIST OF FIGURES 1.1 Glaciers in the North Patagonia Ice Fields ...........................................................8 3.1 Characteristics of ASTER Sensor Systems ........................................................32 3.2 The representation of TPs in stereo pair images ................................................33 3.3 Epipolar generation ............................................................................................35 3.4 Glaciers within the overlapping region of the ASTER 2007 and ASTER 2012, analyzed in this study ...................................................................36 3.5 Glaciers considered in the retreat study. ............................................................42 3.6