Earth's Deep Water Cycle

• Publisher: American Geophysical Union
• Year: 2006
• Tongue: English
• Leaves: 306
• Category: Library

✦ Synopsis

Published by the American Geophysical Union as part of the Geophysical Monograph Series.

The distribution of H2O in the Earth is under debate. Although liquid water covers 70% of the surface, the oceans represent only about 0.025% of the planet's mass-far less water than thought to have been present during Earth's formation. If our planet is "missing" most of its original water, could it reside in the mantle? Can we detect it seismically?

Recognition of the capacity of some deep-mantle minerals to absorb water has propelled an interdisciplinary field of research addressing these two questions, and more. Earth's Deep Water Cycle advances the field with experimental, modeling, and seismic studies that focus on the physical characteristics of "hydrated" minerals, the potentially H2O-rich transition zone (410-660 km depth), and our detection abilities.

Integrated perspectives from four fields of research are featured:

• Mineral physics and geochemistry
• Seismology and electrical conductivity
• Properties of deep hydrous mantle
• Global models and consequences of a deep-Earth water cycle

From experimental synthesis and physical properties measurements to geophysical observations and geodynamic modeling, we are beginning to understand what parameters and data are needed to detect or refute the possibility of water in the deep Earth.

Content:

✦ Table of Contents

Title Page
......Page 3
Copyright
......Page 4
Contents......Page 5
Preface
......Page 7
1. INTRODUCTION......Page 9
2. FLUXES AND RESERVOIRS......Page 10
3. VOLUMES OF HYDRATION......Page 11
4. ELASTIC PROPERTIES......Page 12
5. DISPLACEMENT OF TRANSITIONS......Page 14
6. DISCUSSION......Page 15
REFERENCES......Page 17
1. INTRODUCTION......Page 20
2. THE EFFECTS OF WATER AND OTHER VARIABLES ON SEISMIC PROPERTIES......Page 21
3. SEISMOLGICAL CONSTRAINTS ON MANTLE WATER CONTENT......Page 24
4. DISCUSSION......Page 26
6. CONCLUSIONS......Page 30
REFERENCES......Page 31
1. INTRODUCTION......Page 35
2. ANTIGORITE PHASE RELATIONS......Page 37
3. PHASE RELATIONS OF HIGH-PRESSURE HYDROUS PHASES INCLUDING DHMS......Page 38
4. WATER ACTIVITY IN THE FLUID PHASE AT MANTLE CONDITIONS......Page 40
5. WATER CURCULATION THROUGH THE MANTLE......Page 42
6. ORIGIN OF THE DEEP FOCUS SEISMICITY......Page 44
REFERENCES......Page 46
1. INTRODUCTION......Page 50
2. METHODS......Page 51
3. INFRARED SIGNATURES OF NATURAL OLIVINE CRYSTALS......Page 52
4. MECHANISMS OF HYDROGEN INCORPORATION IN OLIVINE......Page 53
5.DISCUSSION......Page 58
REFERENCES......Page 60
1. INTRODUCTION......Page 62
2. WATER IN TRANSITION ZONE MINERALS......Page 63
3. WATER IN LOWER MANTLW MINERALS......Page 66
4. SUMMARY AND CONCLUSION......Page 70
REFERENCES......Page 72
1. INTRODUCTION......Page 74
3. EXPERIMENTAL METHODS......Page 77
4. ROOM-PRESSURE AND -TEMPERATURE RAMAN SPECTRA OF HYDROUS AND NOMINALLY ANDHYROUS SILICATES......Page 78
5. LOW TEMPERATURE RAMAN SPECTROSCOPY OF LAWSONITE......Page 91
6. HYDROGEN BONDING AT HIGH-PRESSURES IN CLINOCHLORE......Page 92
7. HIGH-PRESSURE RAMAN SPECTROSCOPY OF TRANSITION ZONE SPINELLOIDS AND SPINEL......Page 93
8. CONCLUSIONS......Page 94
REFERENCES......Page 95
1. INTRODUCTION......Page 99
2. EXPERIMENTS AND PRESSURE CALIBRATION......Page 101
3. EXPERIMENTAL RESULTS......Page 102
4. IMPLICATION FOR SEISMIC DISCONTINUITIES AND MANTLE DYNAMICS......Page 107
REFERENCES......Page 111
INTRODUCTION......Page 116
HYDROGEN INCORPORATION MECHANISMS......Page 117
ELECTRICAL CONDUCTIVITY......Page 119
PLASTIC DEFORMATION......Page 122
SOME SPECULATIONS ON THE INFLUENCE OF HYDROGEN ON PLASTIC DEFORMATION IN DEEP MANTLE MINERALS......Page 128
REFERENCES......Page 130
1. INTRODUCTION......Page 133
2. EXPERIMENT......Page 135
3. RESULTS AND DISCUSSION......Page 138
4. SEISMIC STRUCTURE OF A HYDROUS TRANSITION ZONE......Page 144
REFERENCES......Page 145
1. INTRODUCTION......Page 148
2. EXPERIMENTS......Page 149
3. RESULTS AND DISCUSSION......Page 152
4. GEOPHYSICaL IMPLICATIONS......Page 154
REFERENCES......Page 156
INTRODUCTION......Page 159
HIGH P-T PHASES OF H2O......Page 160
THE MELTING CURVES OF H2O......Page 162
PLANETARY AND GEOPHYSICAL APPLICATIONS......Page 166
REFERENCES......Page 167
1. INTRODUCTION......Page 170
2. THREE-DIMENSIONAL EM TOMOGRAPHY......Page 171
3. THREE-DIMENSIONAL CONDUCTIVITY STRUCTURE BENEATH THE NORTH PACIFIC......Page 172
4. ESTIMATING WATER DISTRIBUTION IN THE MANTLE TRANSITION ZONE......Page 175
5. DISCUSSION......Page 176
REFERENCES......Page 177
INTRODUCTION......Page 179
DATA......Page 181
METHOD......Page 182
RESULTS......Page 183
DISCUSSION......Page 185
REFERENCES......Page 189
1. Introduction......Page 192
2. Data and Waveform analysis......Page 195
3. Discussions......Page 198
5. Appendix......Page 202
References......Page 209
Mantle Transition Zone Thickness in the Central South-American Subduction Zone......Page 211
Data and Method......Page 212
Results......Page 213
Discussion......Page 216
Conclusions......Page 219
References......Page 220
1. Introduction......Page 221
2. Conversion of Seismological Data to Geophysi cal Parameters......Page 222
3. Inversion......Page 224
4. Discussion......Page 225
Appendix: some notes on partial derivatives Aij......Page 229
References......Page 231
1. Introduction......Page 233
2. Methods......Page 234
3. Application to subduction zones......Page 236
4. Discussion and conclusion......Page 239
References......Page 243
Introduction......Page 246
Seismic Attenuati on......Page 247
3D Attenuation Observations......Page 248
Discussion and Conclusions......Page 250
References......Page 255
1. INTRODUCTION......Page 257
2. EARTH’S DEEP WATER CYCLE......Page 259
3. A MANTLE EVOLUTION SCENARIO......Page 261
4. DISCUSSION AND CONCLUSIONS......Page 268
REFERENCES......Page 269
Introduction......Page 271
Model Description and Constraints......Page 272
Results......Page 275
Discussion......Page 277
References......Page 280
1. INTRODUCTION......Page 282
2. MINERAL PHYSICS BASIS FOR THE TRANSITION-ZONE WATER FILTER......Page 283
3. MODELS OF MATERIAL CIRCULATION......Page 287
4. GEOPHYSICAL AND GEOCHEMICAL CONSEQUENCES......Page 294
Appendix I: Simple Decompaction Theory for a Heavy Melt Layer......Page 301
Appendix II.......Page 303
References......Page 304