9 Part II: Material Transport Across the Mantle 10 Dynamics of the Upper Mantle in Light of Seismic Anisotropy 10.1 INTRODUCTION 10.2 OBSERVATIONS OF SEISMIC ANISOTROPY 10.3 INTERPRETATION OF SEISMIC ANISOTROPY 10.4 OPEN QUESTIONS 10.5 WAYS FORWARD 10.6 CONCLUSIONS ACKNOWLEDGMENTS REFERENCES 11 Mantle Convection in Subduction Zones: Insights from Seismic Anisotropy Tomography 11.1 INTRODUCTION 11.2 METHOD 11.3 APPLICATIONS 11.4 DISCUSSION 11.5 CONCLUSIONS ACKNOWLEDGMENTS REFERENCES 12 The Cycling of Subducted Oceanic Crust in the Earth’s Deep Mantle 12.1 INTRODUCTION 12.2 OBSERVATIONAL CONSTRAINTS ON THE DISTRIBUTION OF OCEANIC CRUST IN THE DEEP MANTLE 12.3 THE CYCLING OF SUBDUCTED OCEANIC CRUST IN THE DEEP MANTLE 12.4 SUMMARY AND FUTURE WORK 12.5 ACKNOWLEDGMENTS REFERENCES 13 Toward Imaging Flow at the Base of the Mantle with Seismic, Mineral Physics, and Geodynamic Constraints 13.1 INTRODUCTION 13.2 OBSERVATIONAL CONSTRAINTS ON LOWERMOST MANTLE FLOW 13.3 FORWARD MODELING 13.4 JOINT GEODYNAMIC–SEISMIC MODELING 13.5 LIMITATIONS, ADVANCES, AND THE WAY FORWARD 13.6 ACKNOWLEDGMENTS REFERENCES 14 Seismic Imaging of Deep Mantle Plumes 14.1 INTRODUCTION 14.2 PHYSICAL MODELS OF DEEP MANTLE PLUMES 14.3 TRAVELTIME ANALYSIS 14.4 UNDULATIONS OF THE 410‐KM AND 660‐KM PHASE TRANSITIONS 14.5 DIFFRACTION AND SCATTERING EFFECTS 14.6 CONCLUDING REMARKS ACKNOWLEDGMENTS REFERENCES
10 Part III: Surface Expressions 15 Observational Estimates of Dynamic Topography Through Space and Time 15.1 INTRODUCTION 15.2 CONVECTIVE REGIMES AND THEIR SURFACE EXPRESSION 15.3 EARLY OBSERVATIONAL CONSTRAINTS ON LARGE‐SCALE MANTLE FLOW AND THEIR ROLE IN PAST AND PRESENT GEODYNAMIC MODELING 15.4 ESTIMATING PRESENT‐DAY DYNAMIC TOPOGRAPHY 15.5 OBSERVATIONAL ESTIMATES OF TIME‐EVOLVING DYNAMIC TOPOGRAPHY 15.6 FRONTIERS AND OUTSTANDING CHALLENGES