Steven R. Dickman, Binghamton University, USA

• Preface xviiAcknowledgments xviiAbout the Companion Website xixPart I An Earth System Science Framework1 The Birth of the Earth 31.0 Motivation 31.1 The Formation of the Solar System 31.1.1 Overview: Contrasting Theories Versus Solar System Basics 31.1.2 A Monistic Description of Solar System Formation 71.2 Properties of the Solar System 371.2.1 The Spacing of the Planetary Orbits 371.2.2 Moment of Inertia: A Diagnostic Tool for Planetary Interiors 421.2.3 A Brief Description of the Properties of Planets and Moons 451.3 Life in the Solar System, and Beyond 491.3.1 The Search for Planets 491.3.2 Evidence for Life in the Universe 541.3.3 Evidence for Life in Our Solar System 572 The Evolution of Earth’s Atmosphere 712.0 Motivation 712.1 The Differentiation of the Earth 722.1.1 A Core by Condensation? 722.1.2 An Act of Differentiation Created the Core 742.1.3 Consequences of Core Formation 752.2 The Faint Young Sun 862.2.1 The Young Sun’s Changing Luminosity Was Inevitable 872.2.2 A Paradox, and Its Resolution 882.2.3 The Urey Cycle 902.3 Constraints on the Evolution of Atmospheric CO 2 942.3.1 Levels of CO 2 Were (Relatively) Low During Ice House Climates 942.3.2 Other Approaches, and a Synthesis 972.4 The Development of an Oxygen Atmosphere 992.4.1 A Mostly Geology-Based Chronology of the Rise of Oxygen on Earth 1002.4.2 Oxygen and Evolution: An Overview 1122.4.3 Oxygen Chronology: A Synthesis 1163 The Climate System and the Future of Earth’s Atmosphere 1193.0 Motivation 119The Climate System 1203.1 The Circulation of the Atmosphere 1203.1.1 The Sun Is the Ultimate Driving Force 1203.1.2 Basic Concepts Underlying Atmospheric Circulation 1223.1.3 Global Atmospheric Circulation on a Nonrotating Earth 1233.1.4 Global Atmospheric Circulation on the Rotating Earth 1243.1.5 Complications of the Three-Cell Model 1253.1.6 Implications of the Three-Cell Model for Climate and Regional Circulation 1283.1.7 A Brief Jovian Perspective 1313.1.8 Jet Streams in the Atmosphere 1333.1.9 Hurricanes 1363.2 The Circulation of the Oceans 1363.2.1 Thermohaline Convection 1373.2.2 Wind-Driven Circulation 1433.2.3 The Wind-Driven Oceans Move Heat, Too 1473.3 El Niño and the Southern Oscillation: A Coupled Atmosphere—Ocean Phenomenon 1503.3.1 El Niño 1503.3.2 Southern Oscillation 1513.3.3 The Mechanism of a Strong ENSO Event 1553.3.4 The Mechanism of a Weak ENSO Event 1583.3.5 The Return to Normalcy 1593.3.6 There’s an Even Bigger Picture 160The Immediate Future of Our Atmosphere 1633.4 Preliminary Comments 1633.5 Solar Variability on Human Timescales 1633.5.1 Sunspot Cycles 1633.5.2 A Connection Between Sunspots and a Dramatic Change in Earth’s Climate? 1653.5.3 A Few Final Comments on Sunspots 1693.6 Anthropogenic Variations in Climate by the Emission of Greenhouse Gases 1693.6.1 Increases in Greenhouse Gas Abundances 1703.6.2 Direct and Indirect Impacts on Climate Expected From an Increase in Greenhouse Gas Abundances 1733.6.3 Tempered Expectations: Complications in How These Consequences Play Out 1853.6.4 Anthropogenic Variations in Climate: Evidence Concerning Direct Consequences (—If You Insist) 1933.6.5 Anthropogenic Variations in Climate: Evidence Concerning Indirect Consequences 2013.6.6 Anthropogenic Climate Change: Some Final Thoughts 222A Geophysical Perspective: The Rest of This Textbook 223Part II a Planet Driven by Convection4 Basics of Gravity and the Shape of the Earth 2274.0 Motivation 2274.1 The Nature of Gravity 2284.1.1 Simple Expressions of the Law of Gravitation 2284.2 Newton’s Second Law and the Gravity Field 2354.2.1 Cause and Effect, Mass and Weight 2354.2.2 Earth’s Gravity Field, and the Answer to a Really Fundamental Question 2364.2.3 Weighing the Earth 2394.3 The Gravity Field of a Three-Dimensional Earth 2424.3.1 A Guiding Principle 2424.3.2 More Consequences of Gravity Being an Inverse-Square Law Force 2434.3.3 Revisiting Newton’s Law of Gravitation, With Superposition 2464.4 The Shape of the Earth, and Variations of Gravity With Latitude 2484.4.1 A Motivation to Get Complicated 2484.4.2 The Earth Is Not Spherical 2484.4.3 Earth’s Rotation Is the Cause 2494.4.4 A Thorough Description of Centrifugal Force 2524.4.5 Gravity Versus Centrifugal Force on a Rotating Earth 2584.4.6 Indirect Effects of Centrifugal Force on Gravity, and the Idealized Earth 2614.5 Kepler’s Laws 2655 Gravity and Isostasy in the Earth System 2695.0 Motivation 2695.1 Exploring the Earth System with Gravity 2695.1.1 Scaling Down for Gravity Exploration 2695.1.2 The Reduction of Gravity Data 2745.1.3 An Application to the Earth System 2815.1.4 Gravity Data Measured on a Moving Platform 2855.2 Isostasy and the Earth System 2875.2.1 Bouguer’s Discovery and the Principle of Isostasy 2875.2.2 Mechanisms to Achieve Isostatic Balance 2895.2.3 The Moho and Other Evidence of Airy Isostasy 2935.2.4 Airy Isostasy and the Oceanic Response to Atmospheric Pressure Fluctuations 2945.2.5 A Third Mechanism for Achieving Isostatic Compensation 2965.2.6 Isostatic Response to Surface Loads in the Earth System: Anomalous Regions 3005.2.7 Isostatic Response to Surface Loads: Implications for Mantle Rheology 3135.2.8 Global Constraints on Mantle Viscosity 3196 Orbital Perspectives on Gravity 3296.0 Motivation 3296.1 Tides 3296.1.1 Ebbs and Flows 3296.1.2 Tidal Forces 3306.1.3 The Response of the Oceans to Tidal Forces 3326.1.4 The Response of the Solid Earth to Tidal Forces 3356.2 Precession of the Equinoxes and Orbital Effects on Climate 3386.2.1 Precession 3386.2.2 Precession, the Core, and the Geomagnetic Field of the Earth 3446.2.3 Precession Can Affect the Earth’s Climate 3456.2.4 Milankovitch and Mars 3576.3 Satellite Geodesy 3596.3.1 Satellite Orbital Precession 3596.3.2 The Geoid and Satellite Altimetry 3686.3.3 Geoid Versus Spheroid, and Geoidal Heights 3796.3.4 More Perspectives on Global Gravity and the Global Geoid 3836.4 Tidal Friction 3946.4.1 Another Way of Looking at Tides 3946.4.2 The Solid Earth Will End Up in the Middle of It All, and Suffer Greatly 3966.4.3 Tidal Friction Also Affects the Moon’s Orbit 3996.4.4 Tidal Friction Has Consequences for the Earth System 4016.4.5 Tidal Friction Without Oceans, and Astronomical Implications 4036.4.6 Theories of the Origin of the Moon 4057 Basics of Seismology 4097.0 Motivation 4097.1 Stress and Strain 4097.1.1 Stress 4107.1.2 Stress: A Rigorous Description 4127.1.3 Strain 4147.1.4 Strain: A Rigorous Description 4177.2 Relations Between Stress and Strain in Elastic and Nonelastic Materials 4197.2.1 Ideal Models of Different Materials 4207.2.2 Material Properties of an Elastic Medium: Elastic Parameters 4277.3 Elastic Waves 4317.3.1 Descriptions of Waves 4327.3.2 Elastic Waves: The Wave Equation 4337.3.3 Elastic Waves: Reflection and Refraction 4377.4 Surface Waves and Free Oscillations 4527.4.1 Surface Waves 4527.4.2 Free Oscillations 4577.5 Seismic Waves and Exploration of the Shallow Earth 4757.5.1 Refraction Surveys; or, First Arrivals on a Flat Earth 4757.5.2 Refraction Surveys: An Illustration With Possible Hydrogeological Implications 4787.5.3 Refraction Surveys: Thoughts About Multilayered Situations 4817.6 Seismic Waves and Exploration of the Whole Earth: Preliminaries 4827.6.1 Travel Times: Lateral Homogeneity Within the Earth 4827.6.2 Travel Times: Locating Earthquakes 4847.6.3 Travel Times: Identifying Phases on a Seismogram 4898 Seismology and the Interior of the Earth 4918.0 Motivation 4918.1 Seismology and the Dynamic Earth 4928.1.1 Defining Plate Tectonics 4928.1.2 Quantifying Plate Motions 4958.1.3 Plate Motions Through the Ages 4988.1.4 A Last Look at Plates and Plate Motions 5058.1.5 Travel Times and the Interior of the Earth 5108.2 Seismology and the Large-Scale Structure of the Earth 5148.2.1 Travel Times: The Shadow Zone and the Core 5148.2.2 Travel Times: Determining Seismic Velocities Within the Earth 5168.3 Seismic Velocities and the State of Earth’s Interior 5218.3.1 Birch’s Rule 5228.3.2 The Adams-Williamson Equations 5328.3.3 Seismic Tomography 5548.4 Using Earth Models to Learn About the Composition of the Interior 5648.4.1 Equations of State 5648.4.2 High-Pressure Experiments 5689 Heat From Earth’s Interior 5979.0 Motivation 5979.1 Measuring Heat Flow 5989.1.1 Basic Ideas and Practical Challenges 5989.1.2 Heat Flow Data 6009.1.3 Strengthening Our Theoretical Foundation of Heat Flow: An Introduction to Del 6069.2 Heat Sources 6079.2.1 Radioactivity 6079.2.2 Gravitational Energy, Part One 6099.2.3 Heat of Compression 6099.2.4 Gravitational Energy, Part Two 6139.2.5 Moon-Forming Impact 6139.2.6 Tidal Friction 6149.2.7 Another Look at Radioactivity 6149.2.8 Growth of the Inner Core 6189.2.9 Some Reflections, and What Must Come Next 6199.3 Transmission of Heat in Solids 6219.3.1 Conduction Plus Conservation Equals Diffusion 6219.3.2 The Nature of Diffusion 6249.3.3 Some Solutions to the Diffusion Equation 6279.3.4 Learning From Failure: A Deeper Look Into Heat Flow by Conduction 6309.4 Transmission of Heat in Fluids 6389.4.1 Fluid Stability 6399.4.2 How Convection Works in a Fluid 6409.4.3 Heat Transmission in a Convecting Fluid 6499.4.4 Horizontal Convection 6529.4.5 Temperatures Within a Convecting Fluid; Fluid Versus Solid-State Convection 6589.5 More on Surface Heat Flow in the Earth System 6669.5.1 Geothermal Heat and the Thermohaline Circulation 6679.5.2 Subsurface Temperature Variations and Climate Change 66910 Geomagnetism and the Dynamics of the Core 67710.0 Motivation 67710.1 The Earth’s Magnetic Field 67810.1.1 Dipole Fields 67810.1.2 An ‘Elemental’ Description of Magnetic Fields, with Reference to the Earth 68010.1.3 Magnetic Fields: An Overview of the Earth System 68210.2 Global Descriptions of the Internal Field 70710.2.1 Satellite Missions Dedicated to Observing Earth’s Magnetic Fields 70810.2.2 Spherical Harmonics, Once Again 71110.2.3 Back to the Surface: A Closer Look at the Crustal (and Geomagnetic) Fields 71810.3 Snapshots in Time of the Geomagnetic Field 72610.3.1 Current and Recent Snapshots 72610.3.2 Snapshots Further Back in Time 74310.4 Generation of the Geomagnetic Field 75510.4.1 Preliminary Assessments 75510.4.2 Fields Weaken, Fields Strengthen 75810.4.3 Examples of Simple Dynamos 76510.4.4 Inescapable Wisdom From Unavoidable Equations 76810.4.5 Dynamo Flow in a Taylor-Proudman World 77610.4.6 Some Final Thoughts 788References 791Index 891