Preface to Fourth Edition

Preface to First Edition

Chapter 1 Introduction

1.1 Introduction

1.2 History and Perspective

1.3 Organization of the Book

Further Reading

Chapter 2 Transformation of Snow to Ice

2.1 Introduction

2.2 Snow, Firn, and Ice

2.2.1 Density of Ice

2.3 Zones in a Glacier

2.3.1 Distribution of Zones

2.4 Variation of Density with Depth in Firn

2.5 Snow to Ice Transformation in a Dry-snow Zone

2.5.1 Processes

2.5.2 Models of Density Profiles in Dry Firn

2.5.3 Reduction of Gas Mobility

2.6 Hoar Layers

2.7 Transformation When Meltwater Is Present

Further Reading

Chapter 3 Grain-Scale Structures and Deformation of Ice

3.1 Introduction

3.2 Properties of a Single Ice Crystal

3.2.1 Structure

3.2.2 Deformation of a Single Crystal

3.3 Polycrystalline Ice: Grain-scale Forms and Processes

3.3.1 Orientation Fabrics: Brief Description

3.3.2 Impurities and Bubbles

3.3.3 Texture and Recrystallization

3.3.4 Formation of C-axis Orientation Fabrics

3.3.5 Mechanisms of Polycrystalline Deformation

3.4 Bulk Creep Properties of Polycrystalline Ice

3.4.1 Strain Rate and Incompressibility

3.4.2 Deviatoric Stress

3.4.3 Bench-top Experiments: The Three Phases of Creep

3.4.4 Isotropic Creep Behavior

3.4.5 Controls on Creep Parameter A

3.4.6 Recommended Isotropic Creep Relation and Values for A

3.4.7 Anisotropic Creep of Ice

3.5 Elastic Deformation of Polycrystalline Ice

Appendix 3.1

Appendix 3.2: Data for Figure 3.16

Chapter 4 Mass Balance Processes: 1. Overview and Regimes

4.1 Introduction

4.1.1 Notes on Terminology

4.2 Surface Mass Balance

4.2.1 Surface Accumulation Processes

4.2.2 Surface Ablation Processes

4.2.3 Annual (Net) Balance and the Seasonal Cycle

4.2.4 Annual Glacier Balance and Average Specific Balances

4.2.5 Variation of Surface Balance with Altitude

4.2.6 Generalized Relation of Surface Balance to Temperature and Precipitation

4.2.7 Relation of Glacier-wide Balance to the Area-Altitude Distribution

4.3 Mass Balance Variations of Mountain Glaciers

4.3.1 Interannual Fluctuations of Balance

4.3.2 Cumulative Balance and Delayed Adjustments

4.3.3 Regional Variations of Mass Balance

4.4 Englacial Mass Balance

4.4.1 Internal Accumulation

4.4.2 Internal Ablation

4.5 Basal Mass Balance

4.5.1 Basal Accumulation

4.5.2 Basal Ablation

4.6 Mass Loss by Calving

4.6.1 The Calving Spectrum

4.6.2 Calving from Tidewater Glaciers

4.6.3 Calving from Ice Shelves

4.6.4 Calving Relations for Ice Sheet Models

4.7 Methods for Determining Glacier Mass Balance

4.8 Mass Balance Regimes of the Ice Sheets

4.8.1 Greenland Ice Sheet

4.8.2 Antarctic Ice Sheet

Further Reading

Chapter 5 Mass Balance Processes: 2. Surface Ablation and Energy Budget

5.1 Introduction

5.1.1 Radiation

5.1.2 Energy Budget of Earth’s Atmosphere and Surface

5.2 Statement of the Surface Energy Budget

5.2.1 Driving and Responding Factors in the Energy Budget

5.2.2 Melt and Warming Driven by Net Energy Flux

5.3 Components of the Net Energy Flux

5.3.1 Downward Shortwave Radiation

5.3.2 Reflected Shortwave Radiation

5.3.3 Longwave Radiation

5.3.4 Field Example, Net Radiation Budget

5.3.5 Subsurface Conduction and Radiation

5.3.6 Turbulent Fluxes

5.4 Relation of Ablation to Climate

5.4.1 Calculating Melt from Energy Budget Measurements

5.4.2 Simple Approaches to Modelling Melt

5.4.3 Increase of Ablation with Warming

5.4.4 Importance of the Frequency of Different Weather Conditions

v5.4.5 Energy Budget Regimes

Further Reading

Chapter 6 Glacial Hydrology

6.1 Introduction

6.1.1 Permeability of Glacier Ice

6.1.2 Effective Pressure

6.2 Features of the Hydrologic System

6.2.1 Surface (Supraglacial) Hydrology

6.2.2 Englacial Hydrology

6.2.3 Subglacial Hydrology

6.2.4 Runoff from Glaciers

6.3 The Water System within Temperate Glaciers

6.3.1 Direction of Flow

6.3.2 Drainage in Conduits

6.3.3 Drainage in Linked Cavities

6.3.4 Subglacial Drainage on a Soft Bed

6.3.5 Summary of Water Systems at the Glacier Bed

6.3.6 System Behavior

6.4 Glacial Hydrological Phenomena

6.4.1 Jökulhlaups

6.4.2 Antarctic Subglacial Lakes

Further Reading

Chapter 7 Basal Slip

7.1 Introduction

7.1.1 Measurements of Basal Velocity

7.1.2 Local vs. Global Control of Basal Velocity

7.2 Hard Beds

7.2.1 Weertman’s Theory of Sliding

7.2.2 Observations at the Glacier Sole

7.2.3 Improvements to Weertman’s Analysis

7.2.4 Discussion of Assumptions

7.2.5 Comparison of Predictions with Observations

7.2.6 How Water Changes Sliding Velocity on Hard Beds

7.2.7 Sliding of Debris-laden Ice

7.2.8 Sliding at Sub-Freezing Temperatures

7.2.9 Hard-bed Sliding: Summary and Outlook

7.3 Deformable Beds

7.3.1 Key Observations

7.3.2 Till Properties and Processes

7.3.3 Constitutive Behaviors

7.3.4 Slip Rate ub on a Deformable Bed

7.3.5 Large-scale Behavior of Soft Beds

7.3.6 Continuity of Till

7.3.7 Additional Geological Information

7.4 Practical Relations for Basal Slip and Drag

Further Reading

Chapter 8 The Flow of Ice Masses

8.1 Introduction

8.1.1 Ice Flux

8.1.2 Balance Velocities

8.1.3 Actual Velocities

8.1.4 How Surface Velocities Are Measured

8.2 Driving and Resisting Stresses

8.2.1 Driving Stress and Basal Shear Stress

8.2.2 Additional Resisting Forces and the Force Balance

8.2.3 Factors Controlling Resistance and Flow

8.2.4 Effective Driving Force of a Vertical Cliff

8.3 Vertical Profiles of Flow

8.3.1 Parallel Flow

8.3.2 Observed Complications in Shear Profiles

8.4 Fundamental Properties of Extending and Compressing Flows

8.4.1 General Concepts

8.4.2 Uniform Extension or Compression

8.5 General Governing Relations

8.5.1 Local Stress-equilibrium Relations

8.5.2 General Solutions for Stress and Velocity

8.5.3 Vertically Integrated Force Balance

8.5.4 General Mass Conservation Relation (Equation of Continuity)

8.5.5 Vertically Integrated Continuity Equations

8.6 Effects of Valley Walls and Shear Margins

8.6.1 Transverse Velocity Profile Where Basal Resistance Is Small

8.6.2 Combined Effects of Side and Basal Resistances

8.7 Variations Along a Flow Line

8.7.1 Factors Controlling Longitudinal Strain Rate

8.7.2 Local-scale Variation: Longitudinal Stress-gradient Coupling

8.7.3 Large-Scale Variation

8.8 Flow at Tidewater Margins

8.8.1 Theory

8.8.2 Observations: Columbia Glacier

8.9 Ice Sheets: Flow Components

8.9.1 Flow at a Divide

8.9.2 Ice Streams

8.9.3 Ice Shelves

8.9.4 Transition Zone Between Grounded and Floating Ice

8.9.5 Flow Over Subglacial Lakes

8.10 Surface Profiles of Ice Sheets

8.10.1 Profile Equations

8.10.2 Other Factors Influencing Profiles

8.10.3 Relation Between Ice Area and Volume

8.10.4 Travel Times

8.10.5 Local-scale Relation of Surface and Bed Topography

Further Reading

Chapter 9 Temperatures in Ice Masses

9.1 Introduction

9.2 Thermal Parameters of Ice and Snow

9.3 Temperature of Surface Layers

9.4 Temperate Glaciers

9.4.1 Ice Temperature

9.4.2 Origin and Effect of Water

9.4.3 Distribution of Temperate Glaciers

9.5 Steady-state Temperature Distributions

9.5.1 Steady-state Vertical Temperature Profile

9.6 Measured Temperature Profiles

9.7 General Equation of Heat Transfer

9.7.1 Derivation of Equation

9.7.2 Boundary and Basal Conditions

9.8 Temperatures Along a Flow Line

9.8.1 Observations

9.9 Time-varying Temperatures

9.10 Temperatures in Ice Shelves

Chapter 10 Large-Scale Structures

10.1 Introduction

10.2 Sedimentary Layers

10.3 Foliation

10.3.1 Elongate Bubble Forms

10.3.2 Finite Strain

10.4 Folds

10.4.1 Folding in Central Regions of Ice Sheets

10.5 Boudinage

10.6 Faults

10.7 Implications for Ice Core Stratigraphy

10.8 Ogives and Longitudinal Corrugations

10.9 Crevasses

10.9.1 Patterns and Conditions for Occurrence

10.9.2 Crevasse Depth and Propagation

10.9.3 Related Tensional Features

10.10 Structural Assemblages

Further Reading

Chapter 11 Reaction of Glaciers to Environmental Changes

11.1 Introduction

11.2 Reaction to Changes of Mass Balance: Scales

11.2.1 Net Change of Glacier Length

11.2.2 Simple Models for Response

11.2.3 Simple Models for Different Zones

11.3 Reaction to Changes of Mass Balance: Dynamics

11.3.1 Theoretical Framework

11.3.2 Ice Thickness Changes

11.3.3 Relative Importance of Diffusion and Kinematic Waves

11.3.4 Numerical Models of Glacier Variation

11.4 Reactions to Additional Forcings

11.4.1 Response of Glaciers to Ice and Bed Changes

11.4.2 Factors Influencing the Reaction of an Ice Sheet to the End of an Ice Age

11.4.3 Ice Flow Increased by Water Input

11.5 Changes at a Marine Margin

11.5.1 Conceptual Framework

11.5.2 The Tidewater Glacier Cycle

11.5.3 Interactions of Ice Shelves and Inland Ice

11.5.4 Forcing by Sea-level Rise

Further Reading

Chapter 12 Glacier Surges

12.1 Introduction

12.2 Characteristics of Surging Glaciers

12.2.1 Spatial Distribution and Relation to Geological Setting

12.2.2 Distribution in Time

12.2.3 Temperature Characteristics

12.2.4 Characteristics of Form and Velocity

12.3 Detailed Observations of Surges

12.3.1 Surges of Temperate Glaciers

12.3.2 The Role of Water: Variegated Glacier

12.3.3 Surges Where the Bed Is Partly Frozen

12.3.4 Surges of Polythermal Tidewater Glaciers

12.4 Surge Mechanisms

12.4.1 General Evidence Relevant to the Mechanism

12.4.2 The Mechanism for Temperate Glaciers

12.4.3 Polythermal Glaciers

12.5 Surging of Ice Sheets?

12.6 Ice Avalanches

Chapter 13 Ice Sheets and the Earth System

13.1 Introduction

13.2 Interaction of Ice Sheets with the Earth System

13.2.1 Processes Driving Ice Sheet Change

13.2.2 Feedback Processes

13.3 Growth and Decay of Quaternary Ice Sheets

13.3.1 Relation to Milankovitch Forcings

13.3.2 Climate Forcings at the LGM

13.3.3 Onset of Quaternary Cycles

13.3.4 Heinrich Events

13.4 Ice Sheet Evolution Models

13.4.1 Model Components

13.4.2 Model Calibration

13.4.3 Simulations of Quaternary Ice Sheets

Further Reading

Chapter 14 Ice, Sea Level, and Contemporary Climate Change

14.1 Introduction

14.1.1 Equivalent Sea Level

14.1.2 Recent Climate and Sea-level Change

14.2 Global Warming and Mountain Glaciers

14.2.1 History of Glacier Lengths

14.2.2 Worldwide Mass Balance of Mountain Glaciers and Small Ice Caps

14.2.3 Sea-level Forecasts: Mountain Glaciers and Small Ice Caps

14.3 The Ice Sheets and Global Warming

14.3.1 Greenland

14.3.2 Antarctica

14.3.3 Model Forecasts of Ice Sheet Contributions to Sea-level Change

14.3.4 Simple Approaches to Forecasts for the Century Ahead

14.4 Summary

14.4.1 Recent Sea-level Rise

14.4.2 The Twentieth Century

14.4.3 This Century

Chapter 15 Ice Core Studies

15.1 Introduction

15.1.1 Some Essential Terms and Concepts

15.1.2 Delta Notation

15.2 Relation Between Depth and Age

15.2.1 Theoretical Relations

15.2.2 Determination of Ages

15.2.3 Difference of Gas and Ice Ages

15.3 Fractionation of Gases in Polar Firn

15.4 Total Air Content

15.5 Stable Isotopes of Ice

15.5.1 Conceptual Model

15.5.2 Interpretation of Records

15.6 Additional Techniques of Temperature Reconstruction

15.6.1 Borehole Temperatures

15.6.2 Melt Layers

15.6.3 Thermal and Gravitational Fractionation of Gases

15.7 Estimation of Past Accumulation Rates

15.8 Greenhouse Gas Records

15.8.1 Histories of Atmospheric Concentration

15.8.2 Isotopic Compositions of Greenhouse Gases

15.9 Gas Indicators of Global Parameters

15.9.1 Global Mean Ocean Temperature

15.9.2 Global Biological Productivity

15.10 Particulate and Soluble Impurities

15.10.1 Electrical Conductivity Measurement (ECM)

15.10.2 Primary Aerosols

15.10.3 Secondary Aerosols

15.11 Examples of Multiparameter Records from Ice Sheets

15.11.1 Deglacial Climate Change

15.11.2 A Long Record of Climate Cycling

15.12 Low-latitude Ice Cores

15.13 Surface Exposures in Ablation Zones

Further Reading

Appendix: A Primer on Stress and Strain

Index