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Polarimetric SAR As a Tool for Remote Sensing Salt Diapirs, Axel Heiberg Island, Nunavut

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Polarimetric SAR As a Tool for Remote Sensing Salt Diapirs, Axel Heiberg Island, Nunavut Western University Scholarship@Western Electronic Thesis and Dissertation Repository 4-13-2018 2:00 PM Polarimetric SAR as a Tool for Remote Sensing Salt Diapirs, Axel Heiberg Island, Nunavut Elise M. Harrington The University of Western Ontario Supervisor Neish, Catherine D. The University of Western Ontario Graduate Program in Planetary Science A thesis submitted in partial fulfillment of the equirr ements for the degree in Master of Science © Elise M. Harrington 2018 Follow this and additional works at: https://ir.lib.uwo.ca/etd Part of the Geology Commons Recommended Citation Harrington, Elise M., "Polarimetric SAR as a Tool for Remote Sensing Salt Diapirs, Axel Heiberg Island, Nunavut" (2018). Electronic Thesis and Dissertation Repository. 5321. https://ir.lib.uwo.ca/etd/5321 This Dissertation/Thesis is brought to you for free and open access by Scholarship@Western. It has been accepted for inclusion in Electronic Thesis and Dissertation Repository by an authorized administrator of Scholarship@Western. For more information, please contact [email protected]. Abstract The costs and hazards associated with traditional geological mapping have driven rapid advancement of remote predictive mapping techniques using satellite data. However, few studies have implemented synthetic aperture radar for geology. This study uses quad- polarimetric RADARSAT-2 and PALSAR-1 data to produce circular polarization ratio images over Axel Heiberg Island, Nunavut, Canada. These images are used to characterize the radar properties of gypsum and anhydrite diapirs and secondary salt deposits that have been mapped using visible and near infrared, short wave infrared, and thermal infrared spectroscopy. Diapiric salt outcrops appear rough in radar at the C-Band and L-Band (cm- dm) scales, whereas the secondary salts appear smooth. Ground truthing in the field confirms that salt diapirs are rough from millimeter to meter scale, whereas secondary salt minerals are precipitating on smoother surfaces, like floodplains and hillslopes. These results show that radar can be used to differentiate between diapiric and secondary salt exposures. Keywords Polarimetric SAR, salt diapirs, diapirism, salt tectonics, gypsum, Axel Heiberg Island, physical surface properties, polarization signature, multispectral analysis, remote predictive geological mapping, Canadian Arctic i Co-Authorship Statement The spectral mapping of gypsum and anhydrite exposures in this thesis was performed by Maria Shaposhnikova under the supervision of Dr. Catherine Neish and Dr. Livio Tornabene. Future papers will include co-authorship with these colleagues. ii Acknowledgments Thank you to Catherine Neish for being a great supervisor and encouraging a sustainable work-life balance. Thank you to Gordon “Oz” Osinski for including me on two incredible Arctic field seasons. Thank you to Byung-Hun Choe and Michael Zanetti for taking the time to show me how to process radar imagery. Thank you to Kimberly Law for running my XRD samples and spending the time showing me how to interpret the plots. Thank you, Rachel Maj, for helping me survive my first semester in London, Ontario. Thank you to Maria Nguyen and other SFU Earth Sciences alumni and faculty for your kind words of encouragement from afar. Thank you, Beverlee Buzon and Rachel Toyonaga, for putting up with living with me and driving me places. Thank you to my parents for their eternal, unconditional support. Thank you to the Canadian Space Agency for the SOAR grant that funded this project, and for providing the RADARSAT-2 imagery provided for this study. Thank you again for providing student participation initiative grants to fund me to attend the Earth Observation Summit, International Astronautical Congress, and Space Generations Congress. Thank you to the Natural Sciences and Engineering Research Council of Canada for the Canadian Graduate Program – Master’s Program scholarship and to the Government of Ontario for the Ontario Graduate Scholarship. Thank you to the Polar Continental Shelf Program for partially subsidizing our field expenses, providing tasty food, and for being fun people. Thank you to all who provided unseen assistance. RADARSAT-2 Data and Products (c) MacDonald, Dettwiler and Associates, Ltd. (2016, 2017) - All Rights Reserved. RADARSAT is an official trademark of the Canadian Space Agency. iii Table of Contents Abstract ................................................................................................................................ i Co-Authorship Statement.................................................................................................... ii Acknowledgments.............................................................................................................. iii Table of Contents ............................................................................................................... iv List of Tables ..................................................................................................................... vi List of Figures ................................................................................................................... vii List of Appendices ............................................................................................................ xv Chapter 1 ............................................................................................................................. 1 1 Introduction .................................................................................................................... 1 1.1 Remote Sensing and GIS ........................................................................................ 2 1.2 Radar ....................................................................................................................... 4 1.3 Salt Diapirs.............................................................................................................. 7 1.4 Regional Geology of Axel Heiberg Island.............................................................. 9 1.5 Aims and Objectives ............................................................................................. 13 Chapter 2 ........................................................................................................................... 15 2 Methods ........................................................................................................................ 15 2.1 Visible, Near Infrared, and Thermal Infrared Spectroscopy................................. 15 2.2 Polarimetric Radar ................................................................................................ 23 2.3 Ground Truth – Axel Heiberg Island Field Season 2017 ..................................... 34 2.4 Powder X-Ray Diffraction Analysis ..................................................................... 37 Chapter 3 ........................................................................................................................... 42 3 Results .......................................................................................................................... 42 3.1 Radar Characteristics: Circular Polarization Ratio Values ................................... 44 3.2 Ground Truth ........................................................................................................ 48 iv 3.2.1 Diapir Descriptions – Regional Textures .................................................. 50 3.2.2 Diapir Descriptions – Local Textures ....................................................... 51 3.2.3 Perennial Springs ...................................................................................... 54 3.2.4 Secondary Salts ......................................................................................... 56 3.3 XRD Results ......................................................................................................... 59 Chapter 4 ........................................................................................................................... 63 4 Discussion .................................................................................................................... 63 4.1 Diapiric and Non-Diapiric Salt ............................................................................. 63 4.1.1 C-Band vs. L-Band ................................................................................... 64 4.1.2 Spectral, Spatial, and Temporal Resolution .............................................. 66 4.1.3 Remote Sensing and Field Geology .......................................................... 66 4.2 Effects of Weather ................................................................................................ 70 4.3 Terrestrial Salts as a Planetary Analogue ............................................................. 71 4.3.1 Mars .......................................................................................................... 72 4.3.2 Europa ....................................................................................................... 75 4.3.3 Ceres ......................................................................................................... 76 Chapter 5 ........................................................................................................................... 79 5 Conclusions .................................................................................................................. 79 5.1 Limitations and Future Work ...............................................................................
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