A CORRELATION OF WESTERN ARCTIC OCEAN SEDIMENTATION DURING THE LATE HOLOCENE WITH AN ATMOSPHERIC TEMPERATURE PROXY RECORD FROM A GLACIAL LAKE IN THE BROOKS RANGE, ALASKA A thesis submitted to the Kent State University Graduate College in partial fulfillment of the requirements for the degree of Master of Science by Jeffrey M. Harrison May 2013 Thesis written by Jeffrey M. Harrison B.A. Ohio Wesleyan University, 2008 M.S. Kent State University, 2013 Approved by ___________________________________, Advisor Dr. Joseph D. Ortiz ___________________________________, Chair, Department of Geology Dr. Daniel K. Holm ___________________________________, Associate Dean, College of Arts & Sciences Dr. Raymond A. Craig ii TABLE OF CONTENTS LIST OF FIGURES ………………………...………….…………………………… v LIST OF TABLES ……………………………………...….…………………..…… vii ACKNOWLEDGMENTS ……………………………………………..…………... viii CHAPTER 1. INTRODUCTION …………………………………………………… 1 2. MARINE SEDIMENT CORE 2.1 Background …..………………………..…………...…………… 7 2.2 Significance of the Core Location ….....…….…….......…...…… 9 2.3 Methods …….…………………...……..………….......…...…… 12 2.3.1 Chronology .……………….………...…...…… 13 2.3.2 Malvern Analysis .………………..…......….… 15 2.3.3 VPCA Statistical Analysis .……………..….… 22 2.4 Results ………………........….....……..…………..…….……… 24 2.5 Discussion ………….…………...……..……………..………… 31 2.5.1 Sedimentation Processes ……..........…………. 34 2.5.1.1 Sea-Ice ………………….........……. 35 2.5.1.2 Sea-Ice Sedimentation …….....……. 38 2.5.1.3 Sea-Ice Circulation ……..........……. 42 2.5.1.4 Intermittent Suspension ……...……. 45 2.6 Conclusion …….……........….....……..…………..…….……… 48 iii TABLE OF CONTENTS (Cont.) CHAPTER 3. CORRELATION OF TIME-VARYING MULTIVARIATE DATASETS 3.1 Introduction ……………..…….…….....………………...…..… 51 3.2 Temperature Proxy …………….....…..………………….…..… 52 3.3 Correlation of Marine Sedimentation ……………..……........… 59 3.4 Periodicities ……………..……………..………………….....… 66 3.5 Discussion ……………………………..………………..…...… 72 3.6 Conclusion ……………..……………...………………….....… 80 4. SUMMARY ………..…………………...…………………...….…… 82 REFERENCES ……………………………..………………………………..…...… 85 APPENDIX A: Sample Component Scores ……….…..…..……….……..….…… 98 APPENDIX B: Comparison of VPCA Datasets ……….…….…….……….…… 103 iv LIST OF FIGURES Figure 1. Map of the Arctic Region and Surface Circulation …………………...…...… 3 Figure 2. Detailed Map of Study Area and Core Locations ………….….……....…...…4 Figure 3. Map of Arctic Sea-Ice Extent ………………………………….……...…...… 6 Figure 4. Age Model for Core JPC16 ………………………...………….…….…...… 14 Figure 5. Malvern Mastersizer 2000 ……………….…………………….…….…...… 17 Figure 6. Downcore Variation of JPC16 Mean Grain-size ...…………….…….…...… 19 Figure 7. Contour Plot of JPC16 Grain-size Distributions ………………................… 20 Figure 8. Standardized JPC16 Grain-size Data (Z-scores) …..……………………..… 21 Figure 9. Malvern VPCA Component Scores …………………………..…..............… 26 Figure 10. Component Scores Plotted against Grain-size Class …...………….…....… 28 Figure 11. Downcore JPC16 Components through Time ………………..…….......… 30 Figure 12. Mean Filed of Arctic Ocean Ice Drift ………………..……….….....…...… 33 Figure 13. Blue Lake Temperature Reconstruction ….….…….…………...….…....… 56 Figure 14. Magnetic Susceptibility from Burial Lake ……...…..……….……..…...… 57 Figure 15. Composite Blue Lake Varve Thickness Measurements ….…….….…....… 58 Figure 16. Interpolated Age Measurements for PC-1 …..……………….….….…...… 60 Figure 17. Comparison of JPC16 Components with Blue Lake Varves ...….….….. 61-63 Figure 18. Detrended PC-1 Data ……………………….……….……….……..…...… 68 v LIST OF FIGURES (Cont.) Figure 19. Wavelet Analyses ………………………..…………..……….…….….. 70-72 Figure 20. Comparison of JPC16 Grain-size Data and Varves Thicknesses .……....… 73 Figure B.1. Comparison of the Mean Grain-size Composition for JPC16 …….…...…105 Figure B.2. Comparison of the PCA Components for the JPC16 Datasets …….......…108 Figure B.3. Comparison of the Principal Components from the JPC16 Datasets .……110 vi LIST OF TABLES Table 1. VPCA Component Correlation Matrix …...…………...……………….…… 31 Table 2. Correlations between JPC16 components and Blue Lake varves …..….…… 65 Table B.1. Total Variance Explained by the Darby PCA ……………….....…………111 Table B.2. Total Variance Explained by the Thesis PCA …………....………….…...112 vii ACKNOWLEDGMENTS This study is based on a marine core collected by the U.S. Coast Guard Cutter Healy during a sedimentological and oceanographic study in the summer of 2002. A special thanks to Dr. Lloyd Keigwin and crew for obtaining the marine sediment core (JPC16) used here during HLY0204 cruise aboard the USCGC Healy. Funding for the research within this thesis was provided by a NSF grant (ARC-0612384 to Dr. Ortiz). I wish to thank Dr. Dennis Darby, Old Dominion University, for providing an age-depth model for JPC16 and for giving access to samples of the JPC16 sediment core for further analysis at KSU. Additionally, his comments and guidance were very valuable in strengthening the quality of work presented here. I am very thankful to Dr. Mark Abbott, University of Pittsburgh, for providing permission and access to the atmospheric temperature proxy data from Blue Lake and Burial Lake that enable for direct comparison to the marine sedimentation data. I am very grateful to my Advisor, Joseph Ortiz, for his dedication, guidance, and support through the entire research process, especially in helping to comprehend the vast paleoclimate and oceanographic processes of the Arctic Region, plus the various analytical methods that were new to me prior to this research. I cannot thank him enough for showing me the Malvern sample analysis and for his guidance with the PCA statistics and other data analysis procedures. I am thankful to have the privilege to work with viii someone so knowledgeable. Many thanks are due to my thesis committee members: Dr. David Hacker and Dr. Elizabeth Griffith. You both provided me with valuable experiences during my time at Kent State. Dr. Hacker, I cannot thank you enough for the chance to see and learn about “World-Class Geology” and for selecting me as a T.A. for Field Camp; you opened my eyes to what geology is really about. I appreciate the support and help that I received from everyone in the department throughout this process. Merida Keats deserves some special gratitude for her help and patience to resolve minor issues that arose with the Malvern and other laboratory items. Her willingness to help make sure everything was operating properly and to preform quick fixes was a huge blessing. Furthermore, I want to thank the Department of Geology at Kent State University for support during my Master’s program. I am thankful to have had this opportunity to pursue a graduate degree and conduct research on the arctic. Finally, I don’t think I could have accomplished what I have without a great network of support from family and friends. I want to thank my family for their constant encouragement in all of my endeavors. Their help and encouragement has been essential in my pursuit of life goals. I am extremely grateful to my best friend and wonderful wife, Rachel, who has been by my side every step of the way. I am thankful that she was able to read through these pages before the final version and for making valuable suggestions. If she was able to understand everything, I don’t know, but without her I would not have been able to achieve what I have. ix CHAPTER 1 INTRODUCTION Recent climate change has become one of the most popular topics of discussion over the past few years. The Arctic has experienced dramatic environmental changes over the last 30 years (Serreze et al. 2000), marked by a significant decline in the extent and thickness of sea-ice cover both during the summer and winter (Serreze et al. 2003). In the western Arctic Ocean, there has been an overall shift from a predominantly perennial ice pack toward a seasonal sea-ice cover (Rigor and Wallace, 2004; Nghiem et al., 2007). The Arctic Ocean has been viewed by many as an important region because of its high sensitivity to changes in the global climate, as effects tend to be amplified in the Polar Regions. Observations of climate patterns in the Arctic are vital to give scientists a better understanding of current and future variations in our climate system. There is much debate on the relative influence of natural versus anthropogenic forcing on these changes observed within the Arctic sea-ice. There are major changes occurring in the Arctic that researchers have long considered to be indicators of climate change, including later onset of ice formation and earlier break-up of Arctic ice, the overall decline in ice extent, accelerated rates of sea-ice drift and freshwater export, changes in the magnitude and frequency of storm tracks, and 1 2 warming of surface waters and the atmosphere (Darby et al., 2006; Serreze et al., 2000). Detailed records of natural climate variability from the western Arctic allow for better interpretation of climatic patterns and inference of possible forcing mechanisms. To track the climate history of the southern Arctic region and to better predict its future, there needs to be a better understanding of the linkage between variations in atmospheric and marine cycles, as these are important modulators of the global climate cycle. High-resolution studies of the Arctic climatic system will better our understanding of its longer-term variability and further constrain climate models through the use of past analogs. This study is of particular interest because it provides information regarding