CONTENTS Preface Acknowledgements page xi xv 1 Introduction to the study of surface processes 2 The global context 4 Overview of geomorphology 5 Guiding principles 6 Conservation 6 Transport rules 7 Event size and frequency 7 Establishing timing: rates of processes and ages of landscapes 8 What drives geomorphic processes? 8 The surface temperature of the Earth 9 The climate context 9 Summary 13 Problems 14 Further reading 14 2 Whole Earth morphology 16 Why an oblate spheroid? 18 Topographic statistics: Earth s hypsometry 21 Summary 24 Problems 24 Further reading 25 3 Large-scale topography 26 Ocean basins: the marriage of conduction and isostasy 28 Plate tectonics overview 36 The motion of plates 36 Plate speeds 37 Large-scale mountain ranges: orogens 38 Effects of thickening the crust 39 Effects of erosion on the isostatic balance 41 Mantle response times: geomorphology as a probe of mantle rheology 43 Ice sheet and ocean loading and the response of the Earth surface to it 44 Mantle flow and its influence on topography 49 Dynamic topography 49 Topographic oozing of the Tibetan Plateau margin 50 Gooshing of mantle across the continental edge 52 Summary 55 Problems 57 Further reading 59 4 Tectonic geomorphology 60 Deformation associated with individual faults 62 Fault scaling and fault interaction 65 Coulomb stress changes 67 Determination of offsets from modern earthquakes 69 Paleoseismology 71 Strike-slip faults 71 Normal faults 72 Megathrust faults 75 Long-term deformation: cumulative displacement deduced from offsets of geomorphic markers 78 Marine platforms 79 River profiles 83 The special case of corals 84 v in this web service
vi Flexure 86 Generation of mountain ranges by repeated earthquakes 91 Summary 93 Problems 94 Further reading 95 5 Atmospheric processes and geomorphology 96 The Sun 98 Climate and weather processes 99 Why is Earth the water planet? 100 The spatial pattern of radiation 104 Vertical structure of the atmosphere 107 Wind and atmospheric circulation 108 Hadley cells 108 Monsoons 110 Sea breezes 112 Katabatic winds 112 Orographic effects 113 Summary 117 Problems 118 Further reading 119 6 Dating methods, and establishing timing in the landscape 120 Relative dating methods 122 Absolute dating methods 122 Paleomagnetic dating 123 Optically stimulated luminescence (OSL) 123 Amino acid racemization 124 Oxygen isotopes and the marine isotope stages 126 Radiometric dating methods 128 Cosmogenic radionuclides 131 Shallow geothermometry: establishing long-term rates of exhumation 146 Fission tracks 147 Ar/Ar thermochronometry 148 (U-Th)/He method 151 Summary 157 Problems 157 Further reading 159 7 Weathering 160 Weathering as part of erosion 162 The weathered profile 162 The Critical Zone 164 Denudation 165 Mass loss 165 Processes that fracture rock 166 Thermal stress and strain 168 Frost cracking 173 Other fracturing processes 176 The deeper history of fractures 177 Fractures and rock strength 181 Chemical alteration of rock 183 Chemical equilibrium 183 Solubility and saturation 185 Rivers, continental crust, and common chemical weathering reactions 186 Chemical kinetics 191 Long-term carbon cycle 200 Effects of chemical alteration of rock 202 Assessing mass losses (or gains) in regolith 202 Chemical alteration of rock strength 205 The conversion of bedrock to mobile regolith 207 Mobile-regolith production functions 207 Summary 208 Problems 210 Further reading 211 8 Glaciers and glacial geology 212 Glaciology: what are glaciers and how do they work? 214 Types of glaciers: a bestiary of ice 215 Mass balance 216 Ice deformation 219 The rheology 221 Ice wrinkles 1: Glen s flow law 223 Ice wrinkles 2: sliding/regelation 225 Basal motion by till deformation 232 Applications of glaciology 232 Glacier simulations 232 Paleo-climate estimates from glacial valleys 233 Ice sheet profiles 234 Surging glaciers and the stability of ice sheets 236 Tidewater glaciers 237 The great ice sheets: Antarctica and Greenland 241 Glacial geology: erosional forms and processes 245 Erosional processes 245 Abrasion 246 Quarrying 248 Large-scale erosional forms 251 The U-shaped valley 251 Cirques, steps, and overdeepenings: the long valley profile 252 Fjords 255 Depositional forms 257 Moraines 257 Eskers 260 Erosion rates 263 Summary 265 in this web service
vii Problems 267 Further reading 268 9 Periglacial processes and forms 270 Definition and distribution of permafrost 272 Thermal structure 272 Base of the permafrost 273 Active layer depth 275 Latent heat 277 Departures from the steady-state geotherm 278 Geomorphology of periglacial regions 280 Segregation ice and frost heave 280 Upfreezing of stones 283 Patterned ground 285 Ice wedge polygons 286 Solifluction lobes 290 Pingos 290 Thaw lakes 293 The present rapidly changing Arctic 296 Thermokarst 296 Coastal erosion 298 Permafrost and carbon 299 Summary 300 Problems 301 Further reading 303 10 Hillslopes 304 Convexity of hilltops 307 Mass balance 308 Diffusive processes 309 Hillslope processes 313 Rainsplash 313 Creep 320 Solifluction: frost creep and gelifluction 320 Biogenic process examples 325 Pacing hillslopes 328 Landslides 330 The force balance at failure 331 A primer on the behavior of saturated granular materials 334 What oversteepens the slopes? 336 The aftermath 337 Debris flows 340 Hillslope models 344 Summary 345 Problems 346 Further reading 347 11 Water in the landscape 348 Drainage basins 350 Water balance 352 Soil moisture and its distribution with depth 353 Infiltration 355 Groundwater 358 The Dupuit case 360 Groundwater rules of thumb 363 Runoff mechanisms 363 Infiltration capacity 365 Roles of vegetation 365 Evapotranspiration 365 Water storage in the soil 366 Overland flow generation 366 Overland flow of water and its geomorphic consequences 367 The problem of drainage density 370 Sapping and amphitheater-headed canyons 373 Summary of channel head issues 374 Hydrology of a headwater catchment: the Coos Bay experiment 374 Summary 376 Problems 377 Further reading 378 12 Rivers 380 Theory and measurement of turbulent flows in open channels 382 The vertically averaged mean velocity 388 Other equations for the mean velocity 389 Measurement of channel velocity and discharge 391 Summary of theory and measurement of channel flow 394 Hydraulic geometry 395 Floods and floodplain sedimentation 396 The floodplain 399 Channel plan views 399 The braided case 400 The meandering case 401 Channel profiles 405 Character of the bed 407 River slopes 408 The influence of baselevel 409 The Amazon 411 Summary 414 Appendix: The Navier Stokes equation and the origin of the Reynolds and Froude numbers 414 The left-hand side 415 The right-hand side 415 Non-dimensionalization of the Navier Stokes equation 418 Problems 419 Further reading 421 in this web service
viii 13 Bedrock channels 422 Measurement techniques 424 Straths 425 Lava flows 425 Caves 425 Cosmogenic radionuclides on the channel floor 426 Short-term monitoring 426 Erosion processes 428 The stream power approach 428 Abrasion 429 Quarrying 431 Hydraulic wedging 433 Dissolution 433 Knickpoint migration 434 Summary of processes 435 Stream profiles in bedrock channels 435 The channel width problem 445 Empirical constraints 446 Theory 446 Summary 449 Appendix: Future work and research needs 449 Problems 450 Further reading 451 14 Sediment transport mechanics 452 The pieces of the problem 454 Grain entrainment 455 Recent progress in the fluvial realm 459 Modes of transport 461 The saltation trajectory 462 The granular splash 463 Mass flux: transport laws 464 Suspended sediment transport 468 The suspension trajectory 468 The continuum approach 469 Summary 473 Problems 474 Further reading 475 15 Eolian forms and deposits 476 Bedforms 478 Classification of dune types 481 Models of dunes and their stratigraphy 484 Eolian ripples 486 Summary of bedforms 489 Loess 489 Erosion by windblown particles 493 Windblown snow 497 Eolian evidence on Mars 498 Summary 499 Problems 500 Further reading 501 16 Coastal geomorphology 502 The relative movement of land and sea 504 The Pleistocene record 504 Sea level change in the Holocene 505 The last century of sea level change and its causes 506 Rock uplift 507 Waves 508 Origin of waves 508 Transformation of waves 510 Hurricane storm surge 511 Physics of sand movement in the littoral system 512 Sandy coasts 513 Capes and spits 513 Beach cusps 514 Deltas 515 Rocky coasts 520 Coastal littoral sand budget 521 Pocket beaches and headlands 523 Icy coasts 524 The continental shelf 526 Summary 528 Problems 530 Further reading 531 17 The geomorphology of big floods 532 Why should we study large floods? 534 A historical backdrop 534 A recipe for truly big floods: a bunch of water, a breach of the dam 535 Paleoflood analysis 537 Slackwater and separation eddy deposits 538 Estimates of flow competence 538 Paleodischarge estimates 538 The Bonneville flood 538 Glacial floods: Jo kulhlaups 540 The Lake Missoula floods and the channeled scablands 541 Lakes Agassiz and Ojibway 546 The English Channel reinterpreted 549 Noah s flood 549 Floods from the failure of landslide dams 553 Summary 554 Problems 554 Further reading 555 in this web service
ix 18 Whole landscapes 556 The Santa Cruz landscape: introduction 558 Rock uplift: advection around a fault bend 560 Evolution of the terraces 562 Stream channels 563 Terrace ages 565 Evolution of soils on the terraces 567 Implications of the weathering of soils for the hydrology 568 Littoral system 568 Seacliff evolution 573 Long-term evolution of the coastal plan view 579 Summary 580 Problems 580 Further reading 581 Appendix A: Physics 582 Primary units 582 Key definitions 582 Heat transport mechanisms 583 Rheologies 583 Important dimensionless numbers 583 Important natural constants 583 Physical properties 583 Appendix B: Mathematics 584 Numbers worth memorizing 584 Important functions 584 Basic rules of thumb for manipulation of expressions 591 Trigonometry 591 Geometry 592 Volume, area, and circumference 592 Algebra 592 Calculus 592 Derivatives 592 Integrals 594 Mean value theorem 594 Taylor series expansion 594 Ordinary differential equations (ODEs) 595 Partial differential equations (PDEs) 596 Statistics 596 Probability density functions (PDFs) 597 Goodness of fit 599 References 600 Index 635 in this web service