Earth Science: An Introduction, Third Edition
By Marc S. Hendrix, Graham R. Thompson and Jonathan Turk
Contents:
1
EARTH SYSTEMS 1
Introduction 2
The Earth’s Four Spheres 2
The Geosphere 2
The Hydrosphere 5
The Atmosphere 7
The Biosphere 7
Earth Systems 7
Time and Rates of Change in Earth Science 8
Gradual Change in Earth History 10
Catastrophic Change in Earth History 10
Threshold and Feedback Effects 12
Threshold Effects 12
Feedback Mechanisms 13
Humans and Earth Systems 13
2
MINERALS 17
Introduction 18
What Is a Mineral? 18
Naturally Occurring 19
Inorganic 19
Solid 19
The Chemical Composition of Minerals 19
The Crystalline Nature of Minerals 20
Physical Properties of Minerals 20
Crystal Habit 21
Cleavage 21
Fracture 22
Hardness 22
Specific Gravity 23
Color 23
Streak 23
Luster 23
Other Properties 24
Mineral Classes and the Rock-Forming Minerals 24
Silicates 25
Rock-Forming Silicates 25
Carbonates 26
Commercially Important Minerals 27
Harmful and Dangerous Rocks and Minerals 28
Silicosis and Black Lung 28
Asbestos, Asbestosis, and Cancer 28
Radon and Cancer 29
Acid Mine Drainage and Heavy Metals
Contamination 29
DIGGING DEEPER Here to Stay: Mercury 30
3
ROCKS 33
Introduction 34
Rocks and the Rock Cycle 34
The Rock Cycle and Earth Systems Interactions 36
Igneous Rocks 36
Magma: The Source of Igneous Rocks 36
Types of Igneous Rocks 36
Naming and Identifying Igneous Rocks 38
Common Igneous Rocks 39
Granite and Rhyolite 39
Basalt and Gabbro 39
Andesite and Diorite 41
Peridotite and Komatiite 41
Sedimentary Rocks 42
Clastic Sedimentary Rocks 43
Organic Sedimentary Rocks 45
Chemical Sedimentary Rocks 45
Bioclastic Sedimentary Rocks 46
Carbonate Rocks and Global Climate 48
Physical Sedimentary Structures 48
DIGGING DEEPER Gravel Mining and Sustainability 52
Metamorphic Rocks 54
Metamorphic Grade 54
Metamorphic Changes 54
Textural Changes 54
Mineralogical Changes 55
Types of Metamorphism and Metamorphic Rocks 56
4
GEOLOGIC TIME 60
Earth Rocks, Earth History, and Mass Extinctions 61
Extraterrestrial Impacts 63
Volcanic Eruptions 64
Supercontinents and Earth’s
Carbon Dioxide Budget 64
Geologic Time 66
Relative Geologic Time 66
Interpreting Geologic History from Fossils 69
Unconformities and Correlation 69
Unconformities 70
Correlation 73
Absolute Geologic Time 76
Radioactivity and Half-Life 77
Radiometric Dating 77
Sequence Stratigraphy—Interpreting
the Rock Record through Time 78
The Geologic Time Scale 82
The Earliest Eons of Geologic Time:
Precambrian Time 82
The Phanerozoic Eon 84
5
GEOLOGIC RESOURCES 87
Introduction 88
Mineral Resources 88
Ore and Ore Deposits 89
Magmatic Processes 90
Hydrothermal Processes 91
Sedimentary Processes 93
DIGGING DEEPER Manganese Nodules 94
Weathering Processes 94
Mineral Reserves vs. Mineral Resources 95
The Geopolitics of Metal Resources 96
Mines and Mining 98
Energy Resources: Coal, Petroleum, and Natural
Gas 99
Coal 99
Petroleum 100
Natural Gas 102
Unconventional Petroleum and Gas Reservoirs 103
Coal Bed Methane 106
Tar Sands 106
Energy Resources: Nuclear Fuels and Reactors 107
Energy Resources: Renewable Energy 109
Solar Energy 110
Wind Energy 110
Geothermal Energy 111
Hydroelectric Energy 111
Biomass Energy 111
Transmission of Electricity—
The Hidden Costs 111
The Future of Renewable Energy Resources 112
Conservation as an Alternative Energy Resource 113
Technical Solutions 114
Social Solutions 115
Energy for the 21st Century 116
6
THE ACTIVE EARTH 119
The Origins of Continents and Oceans 120
Alfred Wegener and the Origin of an Idea:
The Continental Drift Hypothesis 120
The Earth’s Layers 123
The Crust 125
The Mantle 125
The Lithosphere 125
The Asthenosphere 126
The Mantle below the Asthenosphere 126
The Core 126
The Seafloor Spreading Hypothesis 126
The Theory of Plate Tectonics 130
Divergent Plate Boundaries 131
The Mid-Oceanic Ridge: Rifting in the Oceans 133
Splitting Continents: Rifting in Continental Crust 133
Convergent Plate Boundaries 135
Transform Plate Boundaries 136
The Anatomy of a Tectonic Plate 136
Why Plates Move: The Earth as a Heat Engine 136
Mantle Plumes and Hot Spots 138
Supercontinents 138
Isostasy: Vertical Movement of the Lithosphere 139
How Plate Tectonics Affect Earth’s Surface 140
Volcanoes 140
Earthquakes 140
Mountain Building 142
How Plate Tectonics Affect Earth’s Climate 142
7
EARTHQUAKES AND THE EARTH’S
STRUCTURE 145
Introduction 146
Anatomy of an Earthquake 146
Earthquake Waves 149
Body Waves 150
Surface Waves 150
Measurement of Seismic Waves 151
Measurement of Earthquake Strength 151
Locating the Source of an Earthquake 154
Earthquakes and Tectonic Plate Boundaries 155
Earthquakes at a Transform Plate Boundary: The San
Andreas Fault Zone 155
Earthquakes at Convergent Plate Boundaries 157
Earthquakes at Divergent Plate Boundaries 157
Earthquakes in Plate Interiors 157
Earthquake Damage and Hazard Mitigation 158
How Rock and Soil Influence Earthquake
Damage 158
Construction Design and Earthquake Damage 159
Tsunamis 159
Earthquake Prediction 161
Long-Term Prediction 161
DIGGING DEEPER Earthquakes in Cascadia 162
Short-Term Prediction 164
Studying the Earth’s Interior 164
Discovery of the Crust–Mantle Boundary 164
The Structure of the Mantle 164
Discovery of the Core 165
Density Measurements 165
Earth’s Magnetism 166
8
VOLCANOES AND PLUTONS 170
Magma 171
Processes That Form Magma 171
Environments of Magma Formation 171
Basalt and Granite 175
Granite and Granitic Magma 175
Andesite and Intermediate Magma 175
Partial Melting and the Origin of Continents 175
When Did Continents Form? 175
Partial Melting and the Origin of Granitic
Continents 176
Tectonic Accretion 176
Vertical Mantle Plume Tectonics 176
Magma Behavior 176
Effects of Silica on Magma Behavior 177
Effects of Water on Magma Behavior 177
Plutons 178
Volcanoes 180
Lava and Pyroclastic Rocks 180
Fissure Eruptions and Lava Plateaus 182
Volcano Types 183
Volcanic Explosions:
Ash-Flow Tuffs and Calderas 187
Pyroclastic Flows 187
Calderas 188
DIGGING DEEPER The Destruction of Pompeii 189
DIGGING DEEPER The Yellowstone Volcano 190
Risk Assessment: Predicting Volcanic Eruptions 191
Regional Prediction 191
Short-Term Prediction 191
Volcanic Eruptions and Global Climate 195
9
MOUNTAINS 199
Folds and Faults: Geologic Structures 200
How Rocks Respond to Tectonic Stress 200
Geologic Structures 200
Folds, Faults, and Plate Boundaries 208
Mountains and Mountain Ranges 210
Island Arcs: Subduction Where Two Oceanic Plates
Converge 211
The Andes: Subduction at a Continental Margin 212
The Himalayas: A Collision between Continents 215
Formation of an Andean-Type Margin 216
Continent–Continent Collision 218
The Himalayas Today 218
Mountains and Earth Systems 220
10
WEATHERING, SOIL, AND EROSION 223
Introduction 224
Weathering and Erosion 224
Mechanical Weathering 225
Frost Wedging 225
Abrasion 226
Organic Activity 227
Thermal Expansion and Contraction 227
Chemical Weathering 228
Dissolution 228
Hydrolysis 229
Oxidation 230
Chemical and Mechanical
Weathering Acting Together 230
Soil 232
Components of Soil 232
Soil Horizons 232
Soil Classification 233
Soil-Forming Factors 235
Mass Wasting and Landslides 242
DIGGING DEEPER Soil Erosion and Human
Activities 242
Types of Rapid Mass Wasting 243
Slide 246
Fall 247
Predicting and Avoiding the Effects of Mass
Wasting 247
Why Do Slides, Flows, and Falls Occur? 247
11
FRESHWATER 252
Introduction 253
The Water Cycle 253
Streams 254
Stream Flow and Velocity 254
Stream Erosion and Sediment Transport 256
Downcutting and Base Level 256
Sinuosity of a Stream Channel 258
Drainage Basins and Drainage Divides 261
DIGGING DEEPER The Richest Hill on Earth and Location
of the Idaho-Montana State Line 262
Stream Erosion and Mountains:
How Landscapes Evolve 263
Stream Deposition 263
Floods 265
Flood Control 266
Flood Control, the Mississippi River Delta, and
Hurricane Katrina 267
Lakes 270
The Life Cycle of a Lake 270
Nutrient Balance in Lakes 270
Temperature Layering and Turnover in Lakes 271
Wetlands 271
Groundwater 273
Porosity and Permeability 273
The Water Table and Aquifers 274
Groundwater Movement 275
Hot Springs, Geysers, and Geothermal Energy 277
12
WATER RESOURCES 281
Introduction 282
Water Supply and Demand 282
Domestic Water Use 282
Industrial Water Use 286
Agricultural Water Use 286
Dams and Diversion 287
Surface Water Diversion 287
Groundwater Diversion 292
Groundwater Depletion 293
The Great American Desert 296
The Colorado River 297
Water and International Politics 297
DIGGING DEEPER The Los Angeles Water Project 298
Water Pollution 299
DIGGING DEEPER Love Canal 300
Types of Pollutants 300
How Sewage, Detergents, and Fertilizers Pollute
Waterways 302
Toxic Pollutants, Risk Assessment, and Cost–Benefit
Analysis 302
Groundwater Pollution 303
DIGGING DEEPER Yucca Mountain Controversy 304
Treating a Contaminated Aquifer 306
Nuclear Waste Disposal 306
The Clean Water Act: A Modern Perspective 307
13
GLACIERS AND GLACIATIONS 309
Introduction 310
Formation of Glaciers 310
Alpine Glaciers 310
Continental Glaciers 311
Glacial Movement 311
The Mass Balance of a Glacier 313
Glacial Erosion 314
Erosional Landforms Created by Alpine Glaciers 315
Erosional Landforms Created by a Continental
Glacier 318
Glacial Deposits 318
Landforms Composed of Till 318
DIGGING DEEPER Glacial Erratics and
Canadian Diamonds 320
Landforms Consisting of Stratified Drift 323
The Pleistocene Glaciation 325
Causes of the Pleistocene Glacial Cycles 325
Effects of Pleistocene Continental Glaciers 327
Sea Level Changes with Glaciation 327
Snowball Earth: The Greatest Glaciation in Earth’s
History 327
The Earth’s Disappearing Glaciers 327
14
DESERTS AND WIND 332
Introduction 333
Why Do Deserts Exist? 333
Latitude 333
Mountains: Rain-Shadow Deserts 334
Coastal and Interior Deserts 334
Water and Deserts 335
Desert Streams 335
Desert Lakes 335
Flash Floods 337
Pediments and Bajadas 337
Two American Deserts 338
The Colorado Plateau 338
Death Valley and the Great Basin 340
Wind 341
Wind Erosion 341
Transport and Abrasion 341
Dunes 341
Loess 344
DIGGING DEEPER The North American “Dust
Bowl” 346
Desertification 348
15
OCEAN BASINS 351
The Origin of Oceans 352
The Earth’s Oceans 354
Studying the Seafloor 355
Sampling 355
Remote Sensing 355
DIGGING DEEPER Invaluable sediment archives
recently recovered from the
deep ocean floor 356
Features of the Seafloor 360
The Mid-Oceanic Ridge System 360
Global Sea-Level Changes and the Mid-Oceanic
Ridge System 364
Oceanic Trenches and Island Arcs 365
Seamounts, Oceanic Islands, and Atolls 366
Sediment and Rocks of the Seafloor 369
Ocean-Floor Sediment 370
Continental Margins 372
Passive Continental Margins 372
The Continental Shelf 372
Active Continental Margins 376
16
OCEANS AND COASTLINES 379
Introduction 380
Geography of the Oceans 380
Seawater 381
Salts and Trace Elements 381
Dissolved Gases 382
Temperature 383
Tides 384
Sea Waves 386
Ocean Currents 386
Surface Currents 386
Why Surface Currents Flow in the Oceans 389
Deep-Sea Currents 391
Upwelling 392
The Seacoast 393
Weathering and Erosion on the Seacoast 393
Sediment Transport along Coastlines 393
Tidal Currents 396
Emergent and Submergent Coastlines 396
Factors That Cause Coastal Emergence and
Submergence 396
Beaches 397
Sandy Coastlines 398
Rocky Coastlines 400
Life in the Sea 403
World Fisheries 403
Reefs 405
Global Warming and Rising Sea Level 407
17
THE ATMOSPHERE 410
Introduction 411
Earth’s Early Atmospheres 411
The First Atmospheres: 4.6 to 4.0 Billion Years
Ago 411
When Life Began: 4.0 to 2.6 Billion Years Ago 412
Life, Iron, and the Evolution of the Modern
Atmosphere 413
Systems Interactions That Affected Oxygen Concentration
in Earth’s Early Atmosphere 414
Evolution of the Modern Atmosphere 415
The Modern Atmosphere 416
Atmospheric Pressure 417
Atmospheric Temperature 418
Air Pollution 420
Gases Released When Fossil Fuels Are Burned 421
Acid Rain 422
Consequences of Acid Rain 422
Smog and Ozone in the Troposphere 422
Toxic Volatiles 424
Particulates and Aerosols 425
Depletion of the Ozone Layer 425
18
ENERGY BALANCE IN THE
ATMOSPHERE 430
Introduction 431
Incoming Solar Radiation 431
Absorption and Emission 432
Reflection 433
Scattering 434
The Radiation Balance 434
Energy Storage and Transfer: The Driving
Mechanisms for Weather and Climate 437
Heat and Temperature 437
Heat Transport by Conduction and Convection 438
Changes of State 439
Heat Storage 439
Temperature Changes with
Latitude and Season 440
Temperature Changes with Latitude 440
DIGGING DEEPER Latitude and Longitude 440
The Seasons 441
Temperature Changes with Geography 443
Altitude 443
Ocean Effects 444
Wind Direction 445
Cloud Cover and Albedo 446
19
MOISTURE, CLOUDS, AND WEATHER 449
Moisture in Air 450
Humidity 450
Supersaturation and Supercooling 451
Cooling and Condensation 451
Radiation Cooling 451
Contact Cooling: Dew and Frost 451
Cooling of Rising Air 451
Rising Air and Precipitation 453
Orographic Lifting 453
Frontal Wedging 453
Convection–Convergence 453
Convective Processes and Clouds 453
Types of Clouds 455
Fog 457
Pressure and Wind 458
Pressure Gradient 458
Coriolis Effect 458
Friction 459
Cyclones and Anticyclones 460
Pressure Changes and Weather 460
Fronts and Frontal Weather 461
Warm Fronts and Cold Fronts 462
Occluded Front 463
Stationary Front 465
The Life Cycle of a Midlatitude Cyclone 465
How the Earth’s Surface Features Affect
Weather 466
Mountain Ranges and Rain-Shadow Deserts 466
Forests and Weather 466
Sea and Land Breezes 467
Monsoons 467
Thunderstorms 467
Lightning 468
Tornadoes and Tropical Cyclones 469
Tornadoes 469
Tropical Cyclones 469
Hurricane Katrina 472
Scope of the Disaster 472
Brief History of Gulf Hurricanes 472
El Niño 473
20
CLIMATE 477
Introduction 478
Global Winds and Climate 478
Climate Zones of Earth 480
Humid Tropical Climates: No Winter 481
Dry Climates: Evaporation Greater Than
Precipitation 484
Humid Midlatitude Climates with Mild Winters 484
Humid Midlatitude Climate with Severe Winters 487
Polar Climate 487
Urban Climates 488
21
CLIMATE CHANGE 492
Introduction 493
Climate Change in Earth’s History 493
Measuring Climate Change 495
Historical Records 495
Tree Rings 496
Plant Pollen 496
Oxygen Isotope Ratios in Glacial Ice 496
Glacial Evidence 496
Plankton and Isotopes in Ocean Sediment 496
The Rock and Fossil Record 497
Astronomical Causes of Climate Change 497
Changes in Solar Radiation 497
Bolide Impacts 497
Water and Climate 498
The Natural Carbon Cycle and Climate 498
Carbon in the Atmosphere 498
Carbon in the Biosphere 499
Carbon in the Hydrosphere 499
Carbon in the Crust and Upper Mantle 499
Tectonics and Climate Change 501
Positions of the Continents 501
Mountains and Climate 501
Volcanoes and Climate 501
How Tectonics, Sea Level, Volcanoes, and Weathering
Interact to Regulate Climate 502
Greenhouse Effect: The Carbon Cycle and Global
Warming 503
Consequences of Greenhouse Warming 505
Feedback and Threshold Mechanisms in Climate
Change 511
Albedo Effects 511
Imbalances in Rates of Plant Respiration and
Photosynthesis 511
Changes in Ocean Currents 511
Permafrost and Deep-Sea Methane Deposits 512
22
MOTIONS IN THE HEAVENS 515
The Motions of the Heavenly Bodies 516
Aristotle and the Earth-Centered
Universe 516
The Renaissance and the Heliocentric Solar
System 518
Copernicus 519
Brahe and Kepler 519
Galileo 519
Isaac Newton and the Glue of the Universe 520
The Motions of the Earth and the Moon 521
Motion of the Moon 521
Eclipses of the Sun and the Moon 523
Modern Astronomy 525
Optical Telescopes 525
Telescopes Using Other Wavelengths 526
Emission and Absorption Spectra 526
Doppler Measurements 527
23
PLANETS AND THEIR MOONS 530
The Solar System: A Brief Overview 531
The Terrestrial Planets 534
Atmospheres and Climates of the Terrestrial
Planets 535
Geology and Tectonics of the Terrestrial Planets 538
The Moon: Our Nearest Neighbor 541
Formation of the Moon 542
History of the Moon 542
The Jovian Planets: Size, Compositions, and
Atmospheres 544
Jupiter 544
Saturn 546
Uranus and Neptune 547
Moons of the Jovian Planets 547
The Moons of Jupiter 547
Saturn’s Moons 549
The Moons of Uranus and Neptune 549
Planetary Rings 550
Pluto and Other Dwarf Planets 551
Asteroids, Comets, and Meteoroids 551
Asteroids 551
Comets 552
Meteoroids 554
24
STARS, SPACE, AND GALAXIES 557
Introduction 558
In the Beginning: The Big Bang 558
The Nonhomogeneous Universe 560
The Birth of a Star 561
The Sun 563
The Sun’s Inner Structure 563
The Photosphere 564
The Sun’s Outer Layers 564
Stars: The Main Sequence 565
The Life and Death of a Star 566
Stars about the Same Mass as Our Sun 566
Stars with a Large Mass 568
First- and Second-Generation Stars 569
Neutron Stars, Pulsars, and Black Holes 570
Neutron Stars and Pulsars 570
Black Holes 572
Gamma Ray Bursts 573
Galaxies 573
Galactic Motion 574
The Milky Way 575
The Nucleus of the Milky Way 575
Galactic Nebulae 575
Quasars 576
Looking Backward into Time 577
Dark Matter 578
The End of the Universe 578
Why Are We So Lucky? 578
APPENDICES
A: English-Metric Conversion Chart 582
B: Earth Science Mineral Identification 583
Glossary 585
Index 608