The West Antarctic Ice Sheet: Behavior and Environment

Title page
......Page 5
Copyright page
......Page 6
Contents
......Page 7
Preface
......Page 9
INTRODUCTION......Page 10
SOME ARGUMENTS ON THE POSSIBILITY OF WEST ANTARCTIC ICE-SHEET COLLAPSE......Page 13
COLLAPSE MECHANISMS......Page 15
SUMMARY......Page 17
REFERENCES......Page 18
INTRODUCTION......Page 21
TOPOGRAPHY AND ICE THICKNESS......Page 22
SURFACE CHARACTERISTICS......Page 29
CONCLUSIONS......Page 32
REFERENCES......Page 33
INTRODUCTION......Page 36
THE WEST ANTARCTIC ICE SHEET IN TIME AND SPACE......Page 38
ORIGIN OF THE WEDDELL SEA EMBAYMENT......Page 40
DEVELOPMENT OF THE WEST ANTARCTIC RIFT SYSTEM......Page 46
REFERENCES......Page 49
INTRODUCTION......Page 52
TERTIARY RECORD OF WAIS EVOLUTION......Page 54
LATE QUATERNARY RECORD OF ICE-SHEET EVOLUTION......Page 55
CONCLUSIONS......Page 60
REFERENCES......Page 61
BACKGROUND......Page 65
WESTERN ROSS SEA-TRANSANTARCTIC MOUNTAINS AREA......Page 68
COASTAL AREAS OF MARIE BYRD LAND AND ELLSWORTH LAND......Page 70
INTERIOR NUNATAKS......Page 72
SUMMARY AND CONCLUSIONS......Page 77
REFERENCES......Page 79
1. INTRODUCTION......Page 81
2. VARIATIONS IN ICE SHEET ELEVATION......Page 82
3. ELEVATION HISTORY FROM ICE SHEET MODELS......Page 85
4. EMPIRICAL CONSTRAINTS ON FORMER ICE ELEVATIONS......Page 87
REFERENCES......Page 93
1. INTRODUCTION......Page 97
2. WEST ANTARCTIC ENSO VARIABILITY......Page 99
3. CONFIRMATION OF CULLATHER ET AL. [1996] RESULTS BY SURFACE-BASED OBSERVATIONS......Page 102
4. CIRCULATION CHARACTERISTICS OF THE STRONG EL NIÑO EVENTS OF 1982/83 AND1997/98......Page 104
5. DISCUSSION......Page 107
REFERENCES......Page 108
INTRODUCTION......Page 110
THE ROSS EMBAYMENT AS A GEOLOGICAL FRAMEWORK FOR RBM......Page 111
SEISMIC EVIDENCE FOR POSSIBLE GEOLOGICAL CONTROL ON RBM IN THE SERE......Page 113
AEROGEOPHYSICAL EVIDENCE FOR POSSIBLE GEOLOGICAL CONTROL ON RBM IN THE SERE......Page 114
APPENDIX......Page 123
INTRODUCTION......Page 127
LOCATION OF THE ONSET......Page 128
DETAILED STUDIES OF ONSET AREAS......Page 133
PHYSICAL PROCESSES AT THE ONSET......Page 135
SUMMARY......Page 137
1. INTRODUCTION......Page 141
2. CHARACTERISTICS OF ICE STREAM......Page 142
3. DYNAMIC ANALYSIS......Page 145
4. MIGRATION OF SHEAR MARGINS......Page 153
5. SYNTHESIS......Page 156
REFERENCES......Page 157
BASAL ZONE OF THE WEST ANTARCTIC ICE STREAMS AND ITS ROLE IN LUBRICATION OF THEIR RAPID MOTION......Page 160
1. INTRODUCTION......Page 161
2. OBSERVATIONAL METHODS AND STUDY SITES......Page 162
3. PHYSICAL CONDITIONS IN THE BASAL ZONE......Page 163
4. BASAL MATERIALS AND STRUCTURE......Page 168
5. BASAL SLIDING VS. TILL DEFORMATION......Page 175
6. TILL STRENGTH AND RHEOLOGY......Page 177
7. BASAL WATER SYSTEM......Page 187
8. COMPARISON OF ICE STREAM C WITH ICE STREAMS B AND D......Page 193
9. THEORY......Page 195
REFERENCES......Page 199
INTRODUCTION......Page 203
POTENTIAL SOURCES OF INSTABILITY......Page 215
CONCLUSIONS......Page 217
OUTLOOK......Page 218
REFERENCES......Page 219
INTRODUCTION AND BACKGROUND......Page 222
GLACIOLOGICAL REGIME......Page 225
SHEAR MARGINS......Page 226
BASAL REGIME......Page 228
ONSET OF STREAMING......Page 229
GROUNDING ZONE AND TIDAL FLEXING......Page 230
FLOATING PORTION......Page 232
REFERENCES......Page 234
1. INTRODUCTION......Page 237
2. THE INTERIOR ICE-DRAINAGE BASIN......Page 240
3. THE GLACIER......Page 246
4. THE ICE SHELF......Page 250
6. MASS BALANCE......Page 252
7. DISCUSSION AND CONCLUSIONS......Page 253
REFERENCES......Page 254
INTRODUCTION......Page 257
MAPPING THE ICE STREAMS......Page 258
VELOCITIES......Page 265
MASS BALANCE......Page 266
BED MOBILITY......Page 268
FORCE BUDGET......Page 271
ONSET......Page 274
HYPOTHETICAL CONTROLS......Page 275
CONCLUSIONS......Page 277
APPENDIX......Page 278
REFERENCES......Page 279
1. INTRODUCTION......Page 282
2. TIME OF SLOW-DOWN......Page 284
4. HYPOTHESES FOR SLOW-DOWN......Page 285
5. OBSERVATIONS AND DATA......Page 287
6. DISCUSSION......Page 291
7. CONCLUSION......Page 292
REFERENCES......Page 293