A revised introduction to aeolian geomorphology written by noted experts in the field
The new, revised and updated edition of Aeolian Geomorphology offers a concise and highly accessible introduction to the subject. The text covers the topics of deserts and coastlines, as well as periglacial and planetary landforms. The authors review the range of aeolian characteristics that include soil erosion and its consequences, continental scale dust storms, sand dunes and loess. Aeolian Geomorphology explores the importance of aeolian processes in the past, and the application of knowledge about aeolian geomorphology in environmental management.
The new edition includes contributions from eighteen experts from four continents. All the chapters demonstrate huge advances in observation, measurement and mathematical modelling. For example, the chapter on sand seas shows the impact of greatly enhanced and accessible remote sensing and the chapter on active dunes clearly demonstrates the impact of improvements in field techniques. Other examples reveal the power of greatly improved laboratory techniques. This important text:
- Offers a comprehensive review of aeolian geomorphology
- Contains contributions from an international panel of eighteen experts in the field
- Includes the results of the most recent research on the topic
- Filled with illustrative examples that demonstrate the advances in laboratory approaches
Written for students and professionals in the field, Aeolian Geomorphology provides a comprehensive introduction to the topic in twelve new chapters with contributions from noted experts in the field.
Table of Contents
List of Contributors xi
Preface xiii
1 Global Frameworks for Aeolian Geomorphology 1
Andrew Warren
1.1 Introduction 1
1.2 Wind 1
1.2.1 Wind Systems with Daily Rhythm and Local Scale 1
1.2.1.1 Dust Devils 1
1.2.1.2 Haboobs 1
1.2.1.3 Low‐Level Jets 4
1.2.1.4 Sea Breezes 4
1.2.1.5 Hurricanes, Cyclones, Typhoons 5
1.2.1.6 Mountain Winds 7
1.2.2 Wind Systems with Annual Rhythms and Semi‐Global Scale 8
1.2.2.1 Westerlies 8
1.2.2.2 The Trade Winds 11
1.2.2.3 The Harmattan 12
1.2.2.4 Monsoons 12
1.2.3 The Calmer Globe 13
1.3 Rhythms of Erosivity and Erodibility from the Semi‑Decadal to Hundreds of Thousands of Years 13
1.3.1 Multiannual Rhythms 13
1.3.2 Century‐Scale Rhythms 13
1.3.3 Orbitally‐Forced Rhythms 13
1.4 Frameworks of Sedimentary Supply 16
1.4.1 Hard Rock 16
1.4.2 Sand (63-2000 μm) 16
1.4.2.1 The Fluvial Origins of Most Quartz Sand 18
1.4.3 Coarse Dust (10-63 μm) 18
1.4.4 Fine Dust (< 10 μm) 18
1.5 Plate‐Tectonic Frameworks: A Glimpse 19
1.6 Conclusion 20
Acknowledgements 20
Note 20
Further Reading 20
References 20
2 Grains in Motion 27
Andreas C.W. Baas
2.1 Introduction 27
2.2 The Nature of Wind 27
2.2.1 Turbulent Boundary Layers 27
2.2.2 Turbulence and Coherent Flow Structures 30
2.3 Transport Modes 31
2.4 Ripples 32
2.5 Initiation of Grain Motion 33
2.5.1 Thresholds 33
2.5.2 Grain Size Control and Dust Emission 35
2.5.3 Other Sedimentary Controls 36
2.6 Sand Transport: Steady‐State 36
2.6.1 Saltation Trajectories 36
2.6.2 The Vertical Profile 38
2.6.3 Modification of the Wind 39
2.6.4 Bulk Transport Models 40
2.7 Sand Transport: Natural Environments 44
2.7.1 Fetch and Saturation 45
2.7.2 Spatio‐Temporal Variability 46
2.7.3 Slope 47
2.7.4 Vegetation 48
2.7.5 Sand Roses 50
2.8 Conclusion 51
Further Reading 51
References 52
3 Wind Erosion 61
Jasper Knight
3.1 Introduction 61
3.2 The Processes of Wind Abrasion 61
3.2.1 Environmental Controls on the Wind Transport of Particles 62
3.3 Ventifacts 63
3.3.1 Morphology 64
3.3.2 Wind Abrasion Microfeatures 65
3.3.3 Ventifact Evolution 67
3.4 Yardangs 68
3.4.1 Yardang Morphology and Evolution 69
3.5 Hamadas and Stone Pavements 71
3.6 Deflation Basins and Pans 72
3.7 Discussion 73
3.7.1 Wind Erosion and Boundary Layer Climates 73
3.7.2 Reconstructing Past Wind Patterns from Wind‐Eroded Features 74
3.8 Conclusions 74
Acknowledgements 75
Further Reading 75
References 75
4 Dust: Sources, Entrainment, Transport 81
Joanna Bullard and Matthew Baddock
4.1 Introduction 81
4.2 What Is Dust? 82
4.3 Production and Entrainment 83
4.4 Sources 85
4.5 Dust Events and Weather Systems 93
4.6 Dust in Suspension 98
Further Reading 100
References 100
5 Loess 107
Helen M. Roberts
5.1 Introduction 107
5.2 Definitions of Loess and its Relationship to Dust 107
5.3 Distribution and Thickness of Loess Deposits 109
5.4 Loess Morphology 112
5.5 The Generation of Loess Sediments 114
5.5.1 The ‘Glacial’ Model 116
5.5.2 The ‘Desert’ Model 117
5.5.3 Seasonality and Continuity 118
5.6 Other Accumulations of Dust 119
5.6.1 Dust on the Ocean Floor 120
5.6.2 Ice Cores 120
5.7 The Palaeoclimatic and Palaeoenvironmental Records from Loess and Dust 121
5.8 Dating Loess and Dust Deposits 122
5.9 The Role of Dust in Climate Change 124
5.10 Cultural,Economic, and Environmental Significance of Loess and Dust 125
5.11 Conclusion 127
Further Reading 127
References 128
6 Desert Dunes: Form and Process 133
Giles Wiggs
6.1 Introduction 133
6.2 The Classification of Dunes 134
6.2.1 Major Dune Types and Their Controls 135
6.3 Dune Dynamics 137
6.4 Dune Morphology 141
6.4.1 Barchan Dunes and Transverse Ridges 141
6.4.2 Linear Dunes 143
6.4.3 Star Dunes 145
6.5 Dune Orientation and Alignment 146
6.6 Dune Interactions and Equilibrium 148
6.6.1 Complex Systems Models 148
6.6.2 Analytical Models 150
6.7 Conclusion 151
Further Reading 151
References 151
7 Anchored Dunes 157
Patrick A. Hesp and Thomas A.G. Smyth
7.1 Introduction 157
7.2 Nebkhas and Nebkha Fields 157
7.2.1 Generalities 157
7.2.2 Evolutionary Trends 159
7.3 Shadow Dunes 159
7.4 Foredunes 160
7.5 Lunette or Clay Dunes 162
7.6 Blowouts 163
7.7 Parabolic Dunes 165
7.8 Coastal Transgressive Sand Sheets and Dunefields 166
7.8.1 Semi‐fixed (Stabilising) and Fixed (Stabilised) Desert Dunefields 166
7.9 Echo Dunes 168
7.10 Climbing,Clifftop, Falling, and Lee Dunes 170
7.11 The Influence of Topography on Wind Flow and Dune Orientation and Migration 172
7.12 Conclusion 172
Acknowledgements 172
Further Reading 172
References 172
8 Sand Seas 179
Paul Hesse
8.1 Introduction 179
8.2 The Distribution of Sand Seas 180
8.3 Climatic Factors 181
8.3.1 Wind 181
8.3.2 Precipitation 182
8.4 Topography 186
8.5 Sorting Processes 189
8.6 Geological Factors 190
8.6.1 Lithology 190
8.6.2 Tectonic Setting 190
8.7 A Basin Model of Sand‐Sea Formation 192
8.8 Dune Patterns and Their Origins 195
8.8.1 Sediment Properties (Grain Size and Composition) 195
8.8.2 Climate Change and Changing Wind Regime 197
8.8.3 Sand Supply and Flow Paths 200
8.8.4 Climatic Gradients 200
8.9 Conclusion 200
Further Reading 204
References 204
9 Dune Sediments 209
Charles Bristow and Ian Livingstone
9.1 Introduction 209
9.2 Dune Sands: Mineralogy, Shape, Surface Textures, and Colour 210
9.2.1 Mineralogy 210
9.2.2 Shape 212
9.2.3 Surface Textures 213
9.2.4 Colour 214
9.3 Particle Size Characteristics 216
9.3.1 Particle Size Patterns 219
9.4 Dune Structure 220
9.4.1 Sedimentary Structures in Sand Dunes 220
9.4.2 Bounding Surfaces 223
9.4.3 Sedimentary Models for Dunes and Interdunes 227
9.5 Eolianites 230
9.6 Conclusion 231
Further Reading 231
References 231
10 Dune Palaeoenvironments 237
David S.G. Thomas
10.1 Introduction 237
10.2 A Date with Dunes 238
10.3 A Challenge: Inactive Versus Active Dunes 240
10.3.1 Vegetation 240
10.3.2 Interacting Environmental Controls 241
10.4 Complex Dune Development 245
10.4.1 Complex Dune Profile Records 246
10.5 Interpreting Dated Dune Records 247
10.6 A Schematic View of Interpreting Dune Palaeoenvironmental Records 249
10.6.1 Accumulation: A Better Way to Look at Dune Palaeoenvironmental Sequences? 250
10.7 Conclusion 254
Further Reading 254
References 254
11 Planetary Aeolian Geomorphology 261
Mary C. Bourke, Matthew Balme, Stephen Lewis, Ralph D. Lorenz, and Eric Parteli
11.1 Introduction 261
11.2 Planetary Atmospheres 261
11.2.1 Mars 261
11.2.2 Titan 263
11.2.3 Venus 263
11.3 Planetary Sediment Transport (Mars, Titan, Venus) 263
11.3.1 Mars 264
11.3.2 Venus and Titan 266
11.4 From Sediment Transport to Aeolian Bedforms 266
11.4.1 Deriving Sediment Transport Characteristics from Planetary Bedform Characteristics 267
11.5 Planetary Aeolian Deposition Features: Dunes, Sand Seas, Sediment Source 269
11.5.1 Mars 269
11.5.2 Titan 270
11.5.3 Venus 272
11.6 Aeolian Dust 273
11.6.1 Dust in the Martian Atmosphere 273
11.6.2 Sources of Martian Dust 276
11.6.3 Landforms Associated with Aeolian Dust on Mars 276
11.7 Planetary Wind‐Eroded Landforms 278
11.7.1 Ventifacts 279
11.7.2 Yardangs 279
11.8 Conclusion 280
Further Reading 281
References 281
12 Application 287
Andrew Warren
12.1 Introduction 287
12.2 Wind Erosion and Dust Production from Agricultural and Grazing Land 287
12.2.1 The Dust Bowl 287
12.2.2 Field‐Scale Application of Aeolian Research After the Dust Bowl 290
12.2.3 Field‐Scale Research into Wind Erosion in the Sahel of West Africa 290
12.2.4 Application at Expanding Scales 291
12.2.4.1 More Types of Land Use 291
12.2.4.2 New Sources of Information 292
12.2.4.3 Larger Scales Bring New End‐Users 293
12.2.4.4 Modelling 293
12.3 Shelter,Wind Erosion, and Dust Production: A Possible Confusion of Scale? 296
12.3.1 The Plains Shelterbelt 297
12.4 Blown Sand in the Desert 297
12.4.1 Oasis Agriculture 297
12.4.1.1 Contemporary Sand Fences 298
12.5 Blown Sand on the Coast 299
12.5.1 Blown Sand and Recreation 299
12.5.2 Coastal Protection 300
12.6 Conclusion: Learning from Past Mistakes 300
Notes 302
Further Reading 302
References 303
Index 307
