Aeolian Geomorphology

Ian Livingstone is Professor of Physical Geography and Head of the Graduate School, University of Northampton, UK. Andrew Warren is an Emeritus Professor of Geography at University College London, UK.

• List of Contributors xiPreface xiii1 Global Frameworks for Aeolian Geomorphology 1Andrew Warren1.1 Introduction 11.2 Wind 11.2.1 Wind Systems with Daily Rhythm and Local Scale 11.2.1.1 Dust Devils 11.2.1.2 Haboobs 11.2.1.3 Low‐Level Jets 41.2.1.4 Sea Breezes 41.2.1.5 Hurricanes, Cyclones, Typhoons 51.2.1.6 Mountain Winds 71.2.2 Wind Systems with Annual Rhythms and Semi‐Global Scale 81.2.2.1 Westerlies 81.2.2.2 The Trade Winds 111.2.2.3 The Harmattan 121.2.2.4 Monsoons 121.2.3 The Calmer Globe 131.3 Rhythms of Erosivity and Erodibility from the Semi‑Decadal to Hundreds of Thousands of Years 131.3.1 Multiannual Rhythms 131.3.2 Century‐Scale Rhythms 131.3.3 Orbitally‐Forced Rhythms 131.4 Frameworks of Sedimentary Supply 161.4.1 Hard Rock 161.4.2 Sand (63–2000 μm) 161.4.2.1 The Fluvial Origins of Most Quartz Sand 181.4.3 Coarse Dust (10–63 μm) 181.4.4 Fine Dust (<10 μm) 181.5 Plate‐Tectonic Frameworks: A Glimpse 191.6 Conclusion 20Acknowledgements 20Note 20Further Reading 20References 202 Grains in Motion 27Andreas C.W. Baas2.1 Introduction 272.2 The Nature of Wind 272.2.1 Turbulent Boundary Layers 272.2.2 Turbulence and Coherent Flow Structures 302.3 Transport Modes 312.4 Ripples 322.5 Initiation of Grain Motion 332.5.1 Thresholds 332.5.2 Grain Size Control and Dust Emission 352.5.3 Other Sedimentary Controls 362.6 Sand Transport: Steady‐State 362.6.1 Saltation Trajectories 362.6.2 The Vertical Profile 382.6.3 Modification of the Wind 392.6.4 Bulk Transport Models 402.7 Sand Transport: Natural Environments 442.7.1 Fetch and Saturation 452.7.2 Spatio‐Temporal Variability 462.7.3 Slope 472.7.4 Vegetation 482.7.5 Sand Roses 502.8 Conclusion 51Further Reading 51References 523 Wind Erosion 61Jasper Knight3.1 Introduction 613.2 The Processes of Wind Abrasion 613.2.1 Environmental Controls on the Wind Transport of Particles 623.3 Ventifacts 633.3.1 Morphology 643.3.2 Wind Abrasion Microfeatures 653.3.3 Ventifact Evolution 673.4 Yardangs 683.4.1 Yardang Morphology and Evolution 693.5 Hamadas and Stone Pavements 713.6 Deflation Basins and Pans 723.7 Discussion 733.7.1 Wind Erosion and Boundary Layer Climates 733.7.2 Reconstructing Past Wind Patterns from Wind‐Eroded Features 743.8 Conclusions 74Acknowledgements 75Further Reading 75References 754 Dust: Sources, Entrainment, Transport 81Joanna Bullard and Matthew Baddock4.1 Introduction 814.2 What Is Dust? 824.3 Production and Entrainment 834.4 Sources 854.5 Dust Events and Weather Systems 934.6 Dust in Suspension 98Further Reading 100References 1005 Loess 107Helen M. Roberts5.1 Introduction 1075.2 Definitions of Loess and its Relationship to Dust 1075.3 Distribution and Thickness of Loess Deposits 1095.4 Loess Morphology 1125.5 The Generation of Loess Sediments 1145.5.1 The ‘Glacial’ Model 1165.5.2 The ‘Desert’ Model 1175.5.3 Seasonality and Continuity 1185.6 Other Accumulations of Dust 1195.6.1 Dust on the Ocean Floor 1205.6.2 Ice Cores 1205.7 The Palaeoclimatic and Palaeoenvironmental Records from Loess and Dust 1215.8 Dating Loess and Dust Deposits 1225.9 The Role of Dust in Climate Change 1245.10 Cultural,Economic, and Environmental Significance of Loess and Dust 1255.11 Conclusion 127Further Reading 127References 1286 Desert Dunes: Form and Process 133Giles Wiggs6.1 Introduction 1336.2 The Classification of Dunes 1346.2.1 Major Dune Types and Their Controls 1356.3 Dune Dynamics 1376.4 Dune Morphology 1416.4.1 Barchan Dunes and Transverse Ridges 1416.4.2 Linear Dunes 1436.4.3 Star Dunes 1456.5 Dune Orientation and Alignment 1466.6 Dune Interactions and Equilibrium 1486.6.1 Complex Systems Models 1486.6.2 Analytical Models 1506.7 Conclusion 151Further Reading 151References 1517 Anchored Dunes 157Patrick A. Hesp and Thomas A.G. Smyth7.1 Introduction 1577.2 Nebkhas and Nebkha Fields 1577.2.1 Generalities 1577.2.2 Evolutionary Trends 1597.3 Shadow Dunes 1597.4 Foredunes 1607.5 Lunette or Clay Dunes 1627.6 Blowouts 1637.7 Parabolic Dunes 1657.8 Coastal Transgressive Sand Sheets and Dunefields 1667.8.1 Semi‐fixed (Stabilising) and Fixed (Stabilised) Desert Dunefields 1667.9 Echo Dunes 1687.10 Climbing,Clifftop, Falling, and Lee Dunes 1707.11 The Influence of Topography on Wind Flow and Dune Orientation and Migration 1727.12 Conclusion 172Acknowledgements 172Further Reading 172References 1728 Sand Seas 179Paul Hesse8.1 Introduction 1798.2 The Distribution of Sand Seas 1808.3 Climatic Factors 1818.3.1 Wind 1818.3.2 Precipitation 1828.4 Topography 1868.5 Sorting Processes 1898.6 Geological Factors 1908.6.1 Lithology 1908.6.2 Tectonic Setting 1908.7 A Basin Model of Sand‐Sea Formation 1928.8 Dune Patterns and Their Origins 1958.8.1 Sediment Properties (Grain Size and Composition) 1958.8.2 Climate Change and Changing Wind Regime 1978.8.3 Sand Supply and Flow Paths 2008.8.4 Climatic Gradients 2008.9 Conclusion 200Further Reading 204References 2049 Dune Sediments 209Charles Bristow and Ian Livingstone9.1 Introduction 2099.2 Dune Sands: Mineralogy, Shape, Surface Textures, and Colour 2109.2.1 Mineralogy 2109.2.2 Shape 2129.2.3 Surface Textures 2139.2.4 Colour 2149.3 Particle Size Characteristics 2169.3.1 Particle Size Patterns 2199.4 Dune Structure 2209.4.1 Sedimentary Structures in Sand Dunes 2209.4.2 Bounding Surfaces 2239.4.3 Sedimentary Models for Dunes and Interdunes 2279.5 Eolianites 2309.6 Conclusion 231Further Reading 231References 23110 Dune Palaeoenvironments 237David S.G. Thomas10.1 Introduction 23710.2 A Date with Dunes 23810.3 A Challenge: Inactive Versus Active Dunes 24010.3.1 Vegetation 24010.3.2 Interacting Environmental Controls 24110.4 Complex Dune Development 24510.4.1 Complex Dune Profile Records 24610.5 Interpreting Dated Dune Records 24710.6 A Schematic View of Interpreting Dune Palaeoenvironmental Records 24910.6.1 Accumulation: A Better Way to Look at Dune Palaeoenvironmental Sequences? 25010.7 Conclusion 254Further Reading 254References 25411 Planetary Aeolian Geomorphology 261Mary C. Bourke, Matthew Balme, Stephen Lewis, Ralph D. Lorenz, and Eric Parteli11.1 Introduction 26111.2 Planetary Atmospheres 26111.2.1 Mars 26111.2.2 Titan 26311.2.3 Venus 26311.3 Planetary Sediment Transport (Mars, Titan, Venus) 26311.3.1 Mars 26411.3.2 Venus and Titan 26611.4 From Sediment Transport to Aeolian Bedforms 26611.4.1 Deriving Sediment Transport Characteristics from Planetary Bedform Characteristics 26711.5 Planetary Aeolian Deposition Features: Dunes, Sand Seas, Sediment Source 26911.5.1 Mars 26911.5.2 Titan 27011.5.3 Venus 27211.6 Aeolian Dust 27311.6.1 Dust in the Martian Atmosphere 27311.6.2 Sources of Martian Dust 27611.6.3 Landforms Associated with Aeolian Dust on Mars 27611.7 Planetary Wind‐Eroded Landforms 27811.7.1 Ventifacts 27911.7.2 Yardangs 27911.8 Conclusion 280Further Reading 281References 28112 Application 287Andrew Warren12.1 Introduction 28712.2 Wind Erosion and Dust Production from Agricultural and Grazing Land 28712.2.1 The Dust Bowl 28712.2.2 Field‐Scale Application of Aeolian Research After the Dust Bowl 29012.2.3 Field‐Scale Research into Wind Erosion in the Sahel of West Africa 29012.2.4 Application at Expanding Scales 29112.2.4.1 More Types of Land Use 29112.2.4.2 New Sources of Information 29212.2.4.3 Larger Scales Bring New End‐Users 29312.2.4.4 Modelling 29312.3 Shelter,Wind Erosion, and Dust Production: A Possible Confusion of Scale? 29612.3.1 The Plains Shelterbelt 29712.4 Blown Sand in the Desert 29712.4.1 Oasis Agriculture 29712.4.1.1 Contemporary Sand Fences 29812.5 Blown Sand on the Coast 29912.5.1 Blown Sand and Recreation 29912.5.2 Coastal Protection 30012.6 Conclusion: Learning from Past Mistakes 300Notes 302Further Reading 302References 303Index 307