Keywords:
Glaciers.
;
Electronic books.
Description / Table of Contents:
This 2005 edition of a successful textbook is intended to give upper-level students the tools they need to understand modern glaciology. Practising geologists and glaciologists will also find it useful as a reference book. Relatively simple concepts are introduced first, followed by mathematically more sophisticated chapters. Student exercises are included.
Type of Medium:
Online Resource
Pages:
1 online resource (449 pages)
Edition:
2nd ed.
ISBN:
9780511196881
URL:
https://ebookcentral.proquest.com/lib/geomar/detail.action?docID=228802
DDC:
333.917
Language:
English
Note:
Cover -- Half-title -- Ttile -- Copyright -- Dedication -- Contents -- Preface to the first edition -- Preface to the second edition -- Physical constants relevant to ice -- Derived SI units and conversion factors -- Chapter 1 Why study glaciers? -- Chapter 2 Some basic concepts -- A note on units and coordinate axes -- Glacier size, shape, and temperature -- The condition of incompressibility -- Stresses, strains, and strain rates -- Notation -- Tensors -- Strains and strain rates -- Yield stress -- Deviatoric stresses -- Effective and octahedral shear stresses and strain rates -- Principal stresses and strain rates -- The flow law -- Chapter 3 Mass balance -- The transformation of snow to ice -- Snow stratigraphy -- Dating ice using preserved snow stratigraphy -- Mass balance principles -- Climatic causes of mass balance fluctuations -- The budget gradient -- Other modes of ice loss from valley glaciers -- Calving -- Bottom melting -- Mass balance of polar ice sheets -- Calving of ice shelves -- Bottom melting -- Effect of atmospheric circulation patterns on mass balance -- ENSO and Decadal Oscillations -- Global mass balance -- Summary -- Chapter 4 Flow and fracture of a crystalline material -- Crystal structure of ice -- Dislocations -- Rate-limiting processes -- Drag as the rate-limiting process -- Climb as the rate-limiting process -- Slip on other crystallographic planes -- Inhomogeneous strain -- Internal stresses -- Recrystallization -- Development of fabrics with preferred orientations of c-axes -- Summary -- Deformation mechanism maps -- A flow law for glacier ice -- Fracture -- Summary -- Chapter 5 The velocity field in a glacier -- Measurement of velocity -- Balance velocity -- Shear stress distribution -- Horizontal velocity at depth in an ice sheet -- Horizontal velocity in a valley glacier -- Comparison with measurements.
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Mean horizontal velocity and ice flux -- Vertical velocity -- Submergence and emergence velocities -- Flow field -- Transverse profiles of surface elevation on a valley glacier -- Radar stratigraphy -- Effect of drifting snow on the velocity field -- Ice streams -- Summary -- Chapter 6 Temperature distribution in polar ice sheets -- Energy balance in an ice sheet -- Advection -- Conduction -- Strain heating -- The generalized energy balance equation -- Dependence of K on temperature -- The steady-state temperature profile at the center of an ice sheet -- Simplifying assumptions -- The first integration -- The basal boundary condition -- The second integration -- The boundary condition at the surface -- Melting and freezing at the bed -- Character of the temperature profile -- Error introduced by the assumed vertical velocity distribution -- Temperature profiles in the ablation zone -- Temperature profiles near the surface of an ice sheet -- Temperature distributions far from a divide -- The Column model -- Englacial and basal temperatures along a flowline calculated using the Column model -- A problem with high uAlphaLambda warming rates in the Column model -- Basal temperatures in Antarctica - comparison of solutions using the Column model and a numerical model -- Geomorphic implications -- Summary -- Chapter 7 The coupling between a glacier and its bed -- Sliding -- Regelation -- Plastic flow -- Sliding speed -- Roughness in the Nye-Kamb theory -- Tests of sliding theories -- Weaknesses of present sliding theory -- Rheology of basal ice -- The role of normal pressure -- Cavities and the effect of water pressure -- Deformation of subglacial till -- Cohesion -- Consolidation -- Angle of internal friction -- Void ratio -- Grain fracture and the granulometry of deforming subglacial till -- Strain rates in subglacial till.
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Till rheology - the Coulomb plastic model -- Till rheology - the viscous model -- Sliding of ice over till -- Ploughing -- Depth of deformation in a subglacial till -- Stability of ice streams -- Effect of a frozen bed -- Summary -- Chapter 8 Water flow in and under glaciers: geomorphic implications -- The upper part of the englacial hydraulic system -- Veins and the initial development of passages -- Connections to the surface -- Equipotential surfaces in a glacier -- Alternative derivation of equipotential-plane dip -- Melt rates in conduits -- Water pressures in subglacial conduits on hard beds -- Shapes of subglacial conduits -- Types of subglacial drainage system -- The linked-cavity system -- Transitions between conduit and linked-cavity systems -- Multi-branched arborescent system -- Conduits on deforming till -- Temporal and spatial distribution of drainage system types -- Surges -- Subglacial drainage paths and the formation of eskers -- Sediment supply to eskers -- Size and location of water conduits on eskers -- Ramp structures and esker nets -- Tunnel valleys -- Water pressure and glacier quarrying -- Origin of cirques and overdeepenings -- Summary -- Chapter 9 Stress and deformation -- Stress -- General equations for transformation of stress in two dimensions -- Principal stresses -- Mohr's circle -- Invariants of a tensor -- Extension to three dimensions and introduction of deviatoric stresses -- A yield criterion -- The invariants in plane strain -- Momentum balance -- Deformation -- Logarithmic strain -- General equations for transformation of strain in two dimensions -- Condition that principal axes of stress and strain rate coincide -- Summary -- Chapter 10 Stress and velocity distribution in an idealized glacier -- Solutions for stresses and velocities in plane strain -- Stress solutions in a perfectly plastic medium.
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Velocity solutions in a perfectly plastic medium -- Stress and velocity solutions for a nonlinear material -- Comparison with real glaciers -- Summary -- Chapter 11 Numerical modeling -- Goals of modeling -- Numerical integration -- Finite-difference models -- Implicit methods -- Alternating direction schemes -- Backward, forward, and centered differences -- Non-dimensionalization -- Shallow ice approximation -- Finite-element models -- Initial conditions and forcing -- Validation -- Intercomparison of models -- Sensitivity testing and tuning -- Coupling thermal and mechanical models -- Examples -- Calving -- Role of permafrost in ice sheet dynamics and landform evolution -- Three-dimensional models of ice sheets -- Summary -- Chapter 12 Applications of stress and deformation principles to classical problems -- Collapse of a cylindrical hole -- Tunnel and borehole closure -- Subglacial water conduits -- Calculating basal shear stresses using a force balance -- Creep of floating ice shelves -- Analysis of borehole-deformation data -- Summary -- Chapter 13 Finite strain and the origin of foliation -- The strain ellipse -- Simple and pure shear -- Parameters describing cumulative deformation -- Calculating cumulative strain -- Components of foliation -- Foliation in the marginal zone -- Recumbent folds in basal ice -- Summary -- Chapter 14 Response of glaciers to changes in mass balance -- Positive feedback processes -- Response of a temperate glacier -- Elementary kinematic wave theory -- Analysis of the effect of a small change in mass balance using a perturbation approach -- Solution for a small part of a glacier with uniform longitudinal strain rate and without diffusion -- Effect of diffusion -- The problem at the terminus -- Further study of the response time -- Numerical modeling of glacier responses -- Comparison with observation.
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Nisqually Glacier -- South Cascade Glacier -- Summary -- Appendix Problems -- Chapter 3 -- Chapter 4 -- Chapter 5 -- Chapter 6 -- Chapter 8 -- Chapter 9 -- Chapter 10 -- Chapter 11 -- Chapter 12 -- Chapter 13 -- Chapter 14 -- References -- Index.
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