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Coastal Lake-Sediment Records of Prehistoric Hurricane Strikes In Louisiana State University LSU Digital Commons LSU Master's Theses Graduate School 2004 Coastal lake-sediment records of prehistoric hurricane strikes in Honduras and Turks and Caicos Islands of the Caribbean basin Jason Thomas Knowles Louisiana State University and Agricultural and Mechanical College, [email protected] Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_theses Part of the Social and Behavioral Sciences Commons Recommended Citation Knowles, Jason Thomas, "Coastal lake-sediment records of prehistoric hurricane strikes in Honduras and Turks and Caicos Islands of the Caribbean basin" (2004). LSU Master's Theses. 3433. https://digitalcommons.lsu.edu/gradschool_theses/3433 This Thesis is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Master's Theses by an authorized graduate school editor of LSU Digital Commons. For more information, please contact [email protected]. COASTAL LAKE-SEDIMENT RECORDS OF PREHISTORIC HURRICANE STRIKES IN HONDURAS AND TURKS AND CAICOS ISLANDS OF THE CARIBBEAN BASIN A Thesis Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in Partial Fulfillment of the Requirement for the Degree of Master of Science in The Department of Geography and Anthropology by Jason Thomas Knowles B.A., California State University Long Beach, 2000 August 2004 ACKNOWLEDGMENTS First I would like to thank my advisor, Dr. Kam-biu Liu, for his knowledge, and willingness to share it, and his patience and focus, as I have a propensity to lose both, and for his unending support throughout my research. Dr. Liu’s direction in the preparation for professional meetings was an indispensable resource. I would also like to thank Dr. Liu for his support in making available the funding for the radiocarbon dating used in my research. I would like to thank the Geography and Anthropology Department at Louisiana State University for awarding me the 2004 R.J. Russell field research grant to help fund my expedition to Honduras. I would also like to thank my biogeography lab mates; Lawrence “Mzee” Kiage and Terry “Viejo” McCloskey for their seemingly endless supply of good nature and academic support, and of course to a special thanks to “Mzee” for the endless beatings on the tennis court. I would like to thank my field research collaborators, Robert “Hone Heke” Taylor for his assistance with the field research in Providenciales, as well as his creative housing solutions on the Island of Providenciales, “Kia Kaha” Bob. Thanks to Dr. Matthew “Matthews” Thompson for his invaluable skills during the field work in Honduras, especially for his command of the Spanish language, without which we may have never been able to find a place to “build” a battery for our boats, and of course for his good sense of humor. ii And last but most certainly not least, I would like to thank my loving family; whose support has carried me through my educational years. Thank you for your never ending encouragement and of course for the weekly challenges of the Sunday LA Times Geoquiz! iii TABLE OF CONTENTS ACKNOWLEDGMENTS……...……………………………………...………………….ii LIST OF TABLES……...………………………………………………………………...vi LIST OF FIGURES……………………...………………………………………………vii ABSTRACT……………………...…………………………………………………..…..ix CHAPTER 1. INTRODUCTION………….……………...…………………………...…1 2. LITERATURE REVIEW…………………………………………………3 2.1 Hurricanes……………………...………………………….………….3 2.2 Paleotempestology……………………………………….…………...5 2.3 Ecological Impacts of Hurricanes……...….………………………...12 2.4 The Bermuda High Hypothesis……….……….….…….……………16 3. STUDY AREAS…………………………………………………………23 3.1 Honduras………..……………………………………………………23 i. Hurricane History……….………………………………..27 3.2 Turks and Caicos….………..………………………………………...29 i. Hurricane History……………………….………………..34 4. METHODOLOGY………………………………………………………37 4.1 Storm Signature..……….....…………………………………………37 4.2 Field Methods………….…….………………………………………38 4.3 Laboratory Methods and Data Analysis……..……………………....38 4.4 Statistical Analysis…………..……………………………………….43 4.5 Radiocarbon Dating……………….….……………………………...44 5. RESULTS………………………………………………………………..45 5.1 Laguna de Los Micos……..………………………………………….45 i. Core Stratigraphy……………...……….…....…………...45 ii. Radiocarbon Dating ……………………………....……..54 iii. Statistical Analysis.…...……………….……….………...57 5.2 Lake Sophie i. Core Stratigraphy………………….………...…………...59 ii. Radiocarbon Dating.……………………………………..63 iii. Microfossil Identification…………………….…………..63 6. INTERPRETATION AND DISCUSSION...………...………………….64 6.1 Interpretation of Results, Laguna de Los Micos……………………..64 6.2 Interpretation of Results, Lake Sophie……………………………….67 6.3 Discussion………………………………………………………...….69 iv 7. CONCLUSIONS………………………………………………………...74 7.1 Future Research……………………………………………………...75 BIBLIOGRAPHY………………………………………………………………………..77 APPENDIX A: LOSS-ON-IGNITON RAW DATA…….……………………………...82 APPENDIX B: RADIOCARBON RESULTS.……..…………………………………...94 APPENDIX C: STATISTICAL ANALYSIS RAW DATA..…………………………...99 VITA……...…………………………………………………………………………….111 v LIST OF TABLES 2-1 Saffir/Simpson hurricane disaster-potential scale 6 3-5 Table of all hurricanes of Category 2 or greater passing within 65 nautical miles of Laguna de Los Micos since 1850 30 3-9 Table of all hurricanes of Category 3 or greater passing within 65 nautical miles of Lake Sophie since 1850 36 4-1 Calculation parameters for loss-on-ignition 42 5-1 Radiocarbon (14C) dates from Beta Analytic Inc., Miami, Florida 55 vi LIST OF FIGURES Figure 2-1. Chronology of catastrophic hurricane strikes along the U.S. Gulf Coast during the last 4500 years 10 Figure 2-2. Hypothesized shifts of the Bermuda High during the last 6000 years 22 Figure 3-1. Locations of thesis research sites 24 Figure 3-2. Map of Honduras showing Laguna de Los Micos Location 25 Figure 3-3. Satellite image showing the location of Laguna de Los Micos 26 Figure 3-4. a.) Photograph showing the 50 meter wide sand barrier to Laguna de Los Micos. b) Arrow indicating the sand barrier as seen from Laguna de Los Micos 28 Figure 3-5. Map and table of all hurricanes of Category 2 or greater that have passed within 65 nautical miles of Laguna de Los Micos since 1850 30 Figure 3-6. Map of Turks and Caicos Islands showing Lake Sophie location 31 Figure 3-7. 1:25,000 scale topographic map of Providenciales showing Lake Sophie location 33 Figure 3-8. a) View of Lake Sophie facing east. b) View from top of barrier facing east 35 Figure 3-9. Map and Table of all hurricanes of Category 3 or greater that have passed within 65 nautical miles of Lake Sophie since 1850 36 Figure 4-1. Diagram of hypothesized sand deposition and coring technique 39 Figure 4-2. Loss-on ignition-equipment and methods 41 Figure 5-1. Laguna de Los Micos; site map with coring locations 46 Figure 5-2. Loss-on-ignition and sediment stratigraphy graphs for Laguna de Los Micos, Core 1 47 Figure 5-3. Loss-on-ignition and sediment stratigraphy graphs for Laguna de Los Micos, Core 2 48 Figure 5-4. Loss-on-ignition and sediment stratigraphy graphs for Laguna de Los Micos, Core 3 49 vii Figure 5-5. Loss-on-ignition and sediment stratigraphy graphs for Laguna de Los Micos, Core 4 51 Figure 5-6. Laguna de Los Micos summary of four cores: Loss-on-ignition with stratigraphic correlation and radiocarbon dates 53 Figure 5-7. (A) Statistical analysis results for Core 1, (B) Statistical analysis results for Core 2 58 Figure 5-8. (A) Statistical analysis results for Core 3, (B) Statistical analysis results for Core 4 60 Figure 5-9. Loss-on-ignition and sediment stratigraphy graphs for Lake Sophie, Core A 61 Figure 6-1. Simplified stratigraphic diagram for Laguna de Los Micos 65 Figure 6-2. Simplified stratigraphic diagram for Lake Sophie 68 Figure 6-3. Anticipated 137Cs peak corresponding with Hurricane Donna (1960) 70 viii ABSTRACT This study seeks to apply the geological method of paleotempestology to reconstruct past hurricane activities for Central America and the Caribbean. Landfalling hurricanes may deposit distinct overwash sand layers in coastal lake sediments through storm surges and tidal overwash processes that can be dated to establish a chronology of past hurricane strikes. Proxy records from lake-sediment cores were taken for this study in the spring and summer of 2003 from Lake Sophie, Providenciales Island, Turks and Caicos, and from Laguna de Los Micos, Honduras. Loss-on-ignition analysis revealed many changes in the sediment stratigraphies for both sites that appear to represent overwash sand layers caused by past hurricane landfalls. The identification of the overwash sand layers through loss-on-ignition and grain size analyses and radiocarbon dating allowed for a preliminary estimation of return periods and annual landfall probabilities for the regions around Laguna de Los Micos and Lake Sophie. Four cores taken from Laguna de Los Micos, composed mostly of gyttja, contain two distinct sand layers deposited within 500 years of sediment. Radiocarbon dating indicates that the events occurred around AD 1660 and 1550, suggesting a return period of 250 years and an annual landfall probability of 0.4% for Laguna de Los Micos. The core from Lake Sophie is composed of marl and contains 8 distinctive layers of coarse calcareous sand that are interpreted to be hurricane overwash layers. Radiocarbon dating indicates the core to be around 4240 years old, suggesting a return period of 530 years and an annual landfall probability of 0.18% for Lake Sophie. The return periods and annual landfall probability
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