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Periglacial Landforms of the Ahlmannryggen and Jutulsessen Areas of Western Dronning Maud Land, Antarctica

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Periglacial Landforms of the Ahlmannryggen and Jutulsessen Areas of Western Dronning Maud Land, Antarctica Periglacial landforms of the Ahlmannryggen and Jutulsessen areas of western Dronning Maud land, Antarctica A thesis submitted in fulfilment of the requirement for the degree of MASTER OF SCIENCE of Rhodes University By Nicola Wilmot November 2017 Supervisor Ian Meiklejohn Department of Geography, Rhodes University Abstract Periglacial landforms are a common occurrence in Ahlmannryggen and Jutulsessen areas of western Dronning Maud land (WDML). Classification and formation of these landforms were disputed in literature. In Antarctica information on periglacial landforms is limited or confined to a specific landform. Thus a holistic approach was taken when investigating the periglacial landforms found in WDML. An overview of the existing knowledge base on periglacial landforms in WDML was given which was coupled with the analysis of archival data. The landforms found in this area were patterned ground, openwork block deposits (OBD), rock glaciers, terraces, a pronival rampart and lake ice blisters. With patterned ground being the common periglacial landform in WDML, heave monitoring was used where time-lapse videos were used to investigate the formation processes in patterned ground. From consolidating existing knowledge as well as adding new knowledge on the formation of periglacial landforms, it is clear that the landforms in Antarctica should not be compared to other examples, especially examples from the northern hemisphere. Further research in the formation of periglacial landforms is needed and can be further enhanced with more extensive use of the heave monitoring method in future research. Keywords: periglacial, periglacial landforms, periglacial environment, geomorphology, western Dronning Maud Land, freeze thaw cycles i Acknowledgements I would like to express my gratitude and appreciation to Ian Meiklejohn for always believing in me and pushing me to my very best throughout my master's research. Thanks for giving the me opportunity to be part of the Landscape processes in Antarctic Ecosystem project and experience the environment of Antarctica. Thank you to NRF (National Research Foundation) for funding my research. Thanks goes to SANAP (South African National Antarctic Program) and Directorate Antarctic and Islands of the Department of Environmental Affairs for the logistical support in getting us to Antarctica and to our study sites. To the SANAEIV 55 team for the warm welcome in Antarctica and also for helping us logistically and in the field. Appreciation goes out to Jenna Knox and Tebogo Masebe, as I will never forget our time together in the field. Times were not easy but we got through it together. I will never forget all the memories that were made and our excitement over cool rocks. Thanks goes to the Geography department for all the support. Thank you Abe for assistance in using equipment and the labs. Thanks for always being welcoming and creating a warm environment to work in. General thanks to everyone in the department for all the encouraging words. A big thank you goes to my parents and family for supporting me through this time. Gabrielle Ayres, I want to thank you for taking time in reading my dissertation and giving me guidance. My deepest appreciation goes to Eppie McFarlane for going through my grammar and the style of my dissertation. Going to Antarctica is something that I will never forget. This place pushes you in ways you can't imagine. I have learnt so much from this experience. I have fallen in love with this place and a piece of my heart will always belong there. One day I go will back, to experience it all over again. ii Table of Contents Abstract........................................................................................................................................................... i Acknowledgements....................................................................................................................................... ii Table of Figures............................................................................................................................................. vi List of Tables................................................................................................................................................. ix List of Abbreviations..................................................................................................................................... xi Chapter 1: Introduction................................................................................................................................. 1 1.1. Background......................................................................................................................................... 1 1.2. Academic Problem..............................................................................................................................4 1.3. Aim and Objectives...................................................................................................................... 4 1.4. Structure of Dissertation..................................................................................................................4 Chapter 2: Literature Review .........................................................................................................................5 2.1. Periglacial Environment......................................................................................................................5 2.2. Nivation and Cryoplanation................................................................................................................ 8 2.2.1. Nivation.......................................................................................................................................8 2.2.2. Cryoplanation..............................................................................................................................9 2.2.3. Confusion between the two terms.............................................................................................. 9 2.2.4. A new term proposed................................................................................................................ 10 2.3. Periglacial landforms........................................................................................................................ 10 2.3.1. Patterned Ground...................................................................................................................... 10 2.3.2. Openwork Block deposits (OBDs).............................................................................................. 18 2.4. Rock Glaciers............................................................................................................................... 22 2.5. Terraces........................................................................................................................................25 2.6. Lake ice blisters and frost mounds............................................................................................... 27 2.7. Pronival Rampart..........................................................................................................................28 2.8. Summary ........................................................................................................................................ 32 Chapter 3: Setting ........................................................................................................................................33 3.1. Geography ...................................................................................................................................34 3.2. Geology .......................................................................................................................................34 3.3. Climate ........................................................................................................................................35 3.4. Geomorphology..........................................................................................................................37 Chapter 4: Methods .....................................................................................................................................39 4.1. Mapping ............................................................................................................................................41 4.2. Material Characteristics ....................................................................................................................42 4.2.1. Shape Analysis ...........................................................................................................................42 4.2.2. Particle Size Analysis ..................................................................................................................43 iii 4.2.3. Fabric Analysis.........................................................................................................................47 4.3. Heave monitoring...........................................................................................................................48 4.4 Morphological measurements...........................................................................................................49 4.4.1. Sorted circle and half circle.......................................................................................................49 4.4.2. Polygons ....................................................................................................................................49
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