Subduction Dynamics E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Serie: Geophysical Monograph Series
• Sprache: Englisch

Seitenzahl: 621

Veröffentlichungsjahr: 2015

Beschreibung

Subduction dynamics has been actively studied through seismology, mineral physics, and laboratory and numerical experiments. Understanding the dynamics of the subducting slab is critical to a better understanding of the primary societally relevant natural hazards emerging from our planetary interior, the megathrust earthquakes and consequent tsunamis. Subduction Dynamics is the result of a meeting that was held between August 19 and 22, 2012 on Jeju island, South Korea, where about fifty researchers from East Asia, North America and Europe met. Chapters treat diverse topics ranging from the response of the ionosphere to earthquake and tsunamis, to the origin of mid-continental volcanism thousands kilometers distant from the subduction zone, from the mysterious deep earthquakes triggered in the interior of the descending slabs, to the detailed pattern of accretionary wedges in convergent zones, from the induced mantle flow in the deep mantle, to the nature of the paradigms of earthquake occurrence, showing that all of them ultimately are due to the subduction process. Volume highlights include: * Multidisciplinary research involving geology, mineral physics, geophysics and geodynamics * Extremely large-scale numerical models with sliate-of-the art high performance computing facilities * Overview of exceptional three-dimensional dynamic representation of the evolution of the Earth interiors and of the earthquake and subsequent tsunami dynamics * Global risk assessment strategies in predicting natural disasters This volume is a valuable contribution in earth and environmental sciences that will assist with understanding the mechanisms behind plate tectonics and predicting and mitigating future natural hazards like earthquakes, volcanoes and tsunamis.

Leseprobe

Table of Contents

Cover

Title Page

CONTRIBUTORS

INTRODUCTION: The Impact of Subduction Dynamics on Mantle Flow, Continental Tectonics, and Seismic Hazard

REFERENCES

1 Evidence from Caustic Waveform Modeling for Long Slab Thickening above the 660-km Discontinuity under Northeast Asia: Dynamic Implications

1.1. INTRODUCTION

1.2. CAUSTIC WAVEFORM MODELING AND DATA SOURCES

1.3. SLAB IMAGE IN THE MANTLE TRANSITION ZONE

1.4. UNCERTAINTY ESTIMATES OF THICKNESS OF SLAB

1.5. DYNAMIC SIMULATION OF SLAB THICKENING

1.6. DISCUSSION AND DYNAMIC IMPLICATION

1.7. CONCLUSIONS

ACKNOWLEDGMENT

REFERENCES

2 The Continental Collision Process Deduced from the Metamorphic Pattern in the Dabie-Hongseong and Himalayan Collision Belts

2.1. INTRODUCTION

2.2. METAMORPHIC EVOLUTION ALONG THE DABIE-HONGSEONG COLLISION BELT IN NORTHEAST ASIA

2.3. THE DABIE-SULU COLLISION BELT BETWEEN THE NCB AND SCB IN CHINA

2.4. THE EXTENSION OF THE DABIE-SULU BELT IN CHINA INTO THE HONGSEONG AREA IN KOREA

2.5. THE LATE-PERMIAN TO TRIASSIC COLLISION BELT IN KOREA

2.6. THE EXTENSION OF THE DABIE-HONGSEONG COLLISION BELT INTO JAPAN AND NORTH KOREA

2.7. THE METAMORPHIC TREND ALONG THE DABIE-HONGSEONG COLLISION BELT

2.8. METAMORPHIC EVOLUTION ALONG THE HIMALAYAN COLLISION BELT

2.9. THE METAMORPHISM IN THE WESTERN HIMALAYAN COLLISION BELT

2.10. THE METAMORPHISM IN THE MIDEASTERN HIMALAYAN COLLISION BELT

2.11. THE METAMORPHISM IN THE EASTERN HIMALAYAN COLLISION BELT

2.12. THE METAMORPHIC PATTERN ALONG THE HIMALAYA COLLISION BELT

2.13. DISCUSSION AND TECTONIC IMPLICATION

ACKNOWLEDGMENT

REFERENCES

3 A New Tectonic Model for the Genesis of Adakitic Arc Magmatism in Cretaceous East Asia

3.1. INTRODUCTION

3.2. NUMERICAL MODELSs

3.3. RESULTS

3.4. DISCUSSION

3.5. CONCLUDING REMARKS

ACKNOWLEDGMENT

REFERENCES

4 Incoming Plate Variations along the Northern Manila Trench: Implications for Seafloor Morphology and Seismicity

4.1. INTRODUCTION

4.2. GEOLOGICAL FRAMEWORK

4.3. INCOMING PLATE VARIATION

4.4. DISCUSSION

4.5. CONCLUSION

ACKNOWLEDGMENT

REFERENCES

5 Source of the Cenozoic Volcanism in Central Asia

5.1. INTRODUCTION

5.2. PETROLOGICAL SETTING

5.3. BUOYANCY DRIVEN VISCOUS INSTABILITIES

5.4. NUMERICAL SIMULATIONS

5.5. MODEL RESULTS

5.6. DISCUSSION

5.7. CONCLUSIONS

ACKNOWLEDGMENT

BIBLIOGRAPHY

6 Influence of Variable Thermal Expansivity and Conductivity on Deep Subduction

6.1. INTRODUCTION

6.2. METHOD AND MODEL

6.3. RESULTS

6.4. DISCUSSION AND CONCLUSIONS

ACKNOWLEDGMENT

REFERENCES

7 Slab-driven Mantle Weakening and Rapid Mantle Flow

7.1. INTRODUCTION

7.2. METHODS

7.3. RESULTS

7.4. DISCUSSION

7.5. CONCLUSIONS

ACKNOWLEDGMENT

REFERENCES

8 Influence on Earthquake Distributions in Slabs from Bimaterial Shear Heating

8.1. INTRODUCTION

8.2. NUMERICAL METHOD AND MODEL SETTINGS

8.3. RESULTS

8.4. DISCUSSION

8.5. CONCLUSIONS

ACKNOWLEDGMENT

REFERENCES

9 The Seismology of the Planet Mongo: The 2015 Ionospheric Seismology Review

9.1. ORIGINS

9.2. IONOSPHERIC SEISMOMETERS

9.3. THE GPS REVOLUTION: FROM POINT MEASUREMENTS TO IMAGES

9.4. THE GREAT SUMATRA TSUNAMI IN THE IONOSPHERE

9.5. THE TOHOKU EARTHQUAKE AND TSUNAMI

9.6. PHYSICAL PROPERTIES OF

AW

Rayleigh

,

IGW

tsuna

, AND

AGW

epi

9.7. CONCLUSION

ACKNOWLEDGMENT

REFERENCES

10 Why We Need a New Paradigm of Earthquake Occurrence

10.1. INTRODUCTION

10.2. MODELS OF EARTHQUAKES

10.3. THE CHARACTERISTIC EARTHQUAKE MODEL

10.4. UNCHARACTERISTIC EARTHQUAKES

10.5. THE PSHA APPROACH TO EARTHQUAKE-HAZARD MODELING

10.6. PROBABILISTIC FORECASTS OF INDIVIDUAL EARTHQUAKES

10.7. CONCLUSION

REFERENCES

Index

End User License Agreement

List of Tables

Chapter 01

Table 1.1 Information of earthquakes used in caustic waveform modeling.

Chapter 02

Table 2.1 Representative microprobe analyses of garnet and omphacite in retrograde eclogites from the Bibong area.

Table 2.2 SHRIMP U-Pb zircon data from retrograde eclogite in the southwestern part of the Gyeonggi Massif, South Korea.

Table 2.3 Whole rock compositions of representative mangerites and gabbros in the Odesan area, the eastern part of the Gyeonggi Massif, South Korea.

Table 2.4 SHRIMP U-Pb zircon data from the mangerite and gabbro in the Odesan area.

Table 2.5 SHRIMP U-Pb zircon data from spinel granulite in the Odesan area, South Korea.

Table 2.6 The summary of the metamorphic evolution along the Dabie-Hongseong collision belt.

Table 2.7 The summary of the metamorphic evolution along the Himalayan collision belt.

Chapter 05

Table 5.1 Results of the models with 64, 125 and 216 diapirs organized in a perturbed lattice configuration and varying inner viscosity.

Table 5.2 Outcomes of the models with randomly placed diapirs with compaction varying between 0.1 and 0.4.

Chapter 06

Table 6.1 Model parameters.

Table 6.2 Phase-dependent coefficients for the parameterizations of thermal expansivity (equation (6.12)) and thermal conductivity (equation (6.13)).

Table 6.3 Model list.

Chapter 07

Table 7.1 Dimensionalization parameters.

Table 7.2 Flow law parameters, assuming diffusion and dislocation creep of wet olivine.

Table 7.3 Summary of model parameters and results.

Chapter 08

Table 8.1 Descriptions of input parameters

List of Illustrations

Introduction

Figure I.1 Sketch of some of the dynamics investigated in this book. The history of the effects of the subduction process are largely observed in the tectonic structures of the overriding plate, as shown by the chapters focusing on the Eurasian continent (see Figure I.2). The most dramatic events caused by Subducting plates are the large thrust earthquakes (see Chapter 10 by

Geller

et al

.). Megathrusts and tsunamis also cause waves in the ionosphere, as illustrated in the panel on the top right. Rayleigh waves propagate due to both the quake and to the tsunami (see Chapter 9 by Occhipinti). The down-going slab induces a complex mantle flow, as shown by M. A. Jadamec in Chapter 7. Inside the slab, earthquakes are detected down to the transition between upper and lower mantle, but their mechanism is still debated (see So and Yuen in Chapter 8, e.g. about the hypocenter distribution within the Tonga slab on the bottom right panel). Thermal expansivity and conductivity gradients estimates are shown in the bottom right panels. Their role in mantle dynamics is analized in

Tosi et al.

, Chapter 6.

Figure I.2 Summary of the Asian regions covered in this volume overlaying a overview of the Asian tectonics. The map is modified after [

Yin

, 2010]. Chapter 2 from Chang Wahn Oh and Chapter 9 by Giovanni Occhipinti cover two separate regions.

Chapter 01

Figure 1.1 Diagram of caustic waveforms. (a) Three consecutive phases are expected to arrive at the receiver side. These are the direct AB phase, a wave diving above the discontinuity; the reflected BC phase, a wave reflected from the discontinuity; and the CD phase diving below the discontinuity. (b) Synthetic transversal displacement for an assumed epicentral depth of 520 km. The locations of caustic points are very sensitive to the velocity structure around the discontinuity. (c) Iasp91 model used for the synthetic waveform calculation.

Figure 1.2 (a) Synthetic seismograms at 20° epicentral distance (∆) for transversal component S wave calculated for iasp91 model and three different models (c). The depth of the event is 520 km. The trade-off between the depth of the interface and velocity variation around the 660-km discontinuity is not well resolved due to the similarity of the waveforms in a single seismogram. (b) Predicted caustic-wave travel-time after aligning seismograms with the epicentral distance. Significant discrepancy appeared in the major features of caustic points, which can be used to discriminate between different models. (c) Different models used for calculation of (a) and (b). Note that the reference model iasp91 (black line) is overlapped with the other three models.