Mantle circulation and the lateral migration of subducted slabs

The irregular motions of plates and the irregular distribution of plate consumption and generation require that subduction zones and descending lithospheric slabs migrate laterally. Absolute plate motions indicate that slab migration is generally retrograde; that is, it is opposite to the direction of motion of the plates to which the slabs are attached, at rates of 10--25 mm yr/sup -1/. As a result, the downward motions of slabs are generally steeper than their dips, probably because of their negative buoyancy relative to the surrounding mantle. An important consequence of lateral slab migration is the displacement of material away from one side of the slab and inward flow of an equal volume toward the other side. This generates a mass flux in the mantle that is comparable in magnituide with the flux involved in the overturn of the oceanic lithosphere. The flow induced by slab migration is, therefore, an important part of the large-scale mantle circulation associated with plate motions. Two-dimensional numerical models with retrograde slab migration explicitly prescribed as a boundary condition show that migrating slabs, in contrast with nonmigrating ones, are at an angle to streamlines in the surrounding mantle.

[1]  G. Schubert,et al.  Finite element calculations of very high Rayleigh number thermal convection , 1985 .

[2]  A. Cox,et al.  Change in motion of Pacific plate at 5 Myr BP , 1985, Nature.

[3]  S. Hart.  A large-scale isotope anomaly in the Southern Hemisphere mantle , 1984, Nature.

[4]  T. Jordan,et al.  Slab penetration into the lower mantle , 1984 .

[5]  Bradford H. Hager,et al.  The distribution of earthquakes with depth and stress in subducting slabs , 1984 .

[6]  D. Giardini,et al.  Deep seismicity and modes of deformation in Tonga subduction zone , 1984, Nature.

[7]  B. Hager,et al.  Subduction, back-arc spreading and global mantle flow , 1983 .

[8]  D. Mckenzie.  The earth's mantle , 1983 .

[9]  W. J. Morgan.  Hotspot Tracks and the Early Rifting of the Atlantic , 1983 .

[10]  C. G. Chase,et al.  The modern geoid and ancient plate boundaries , 1983 .

[11]  P. R. Cobbold,et al.  Propagating extrusion tectonics in Asia: New insights from simple experiments with plasticine , 1982 .

[12]  F. Richter,et al.  A parameterized model for the evolution of isotopic heterogeneities in a convecting system. [for earth mantle] , 1982 .

[13]  G. Packham.  Foreword to papers on the tectonics of the southwest Pacific region , 1982 .

[14]  W. Alvarez,et al.  Geological evidence for the geographical pattern of mantle return flow and the driving mechanism of plate tectonics , 1982 .

[15]  P. Alfeld,et al.  Thermal modeling of the geometry of subduction with implications for the tectonics of the overriding plate , 1982 .

[16]  Seiya Uyeda,et al.  Subduction zones: An introduction to comparative subductology , 1982 .

[17]  S. Uyeda,et al.  Tectonic Processes and the History of the Mariana Arc: A Synthesis of the Results of Deep Sea Drilli , 1982 .

[18]  B. Parsons.  The rates of plate creation and consumption , 1981 .

[19]  Bradford H. Hager,et al.  A simple global model of plate dynamics and mantle convection , 1981 .

[20]  Hiroo Kanamori,et al.  Seismicity and the subduction process , 1980 .

[21]  R. Duncan,et al.  Linear volcanic chains — recording plate motions? , 1980 .

[22]  C. Jaupart,et al.  The heat flow through oceanic and continental crust and the heat loss of the Earth , 1980 .

[23]  Raymond Jeanloz,et al.  Convection, composition, and the thermal state of the lower mantle , 1979 .

[24]  G. Davies,et al.  Moving lithospheric plates and mantle convection , 1979 .

[25]  J. Oliver,et al.  A study of shallow global mantle flow due to the accretion and subduction of lithospheric plates , 1979 .

[26]  J. Jackson,et al.  Seismotectonic implications of relocated aftershock sequences in Iran and Turkey , 1979 .

[27]  H. Kanamori,et al.  Back-arc opening and the mode of subduction , 1979 .

[28]  B. Hager,et al.  Kinematic models of large‐scale flow in the Earth's mantle , 1979 .

[29]  G. Schubert.  Subsolidus Convection in the Mantles of Terrestrial Planets , 1979 .

[30]  C. G. Chase.  Asthenospheric counterflow: a kinematic model , 1979 .

[31]  G. Schubert,et al.  Mantle flow pressure and the angle of subduction - Non-Newtonian corner flows , 1978 .

[32]  C. G. Chase.  Extension behind island arcs and motions relative to hot spots , 1978 .

[33]  P. Molnar,et al.  Interarc spreading and Cordilleran tectonics as alternates related to the age of subducted oceanic lithosphere , 1978 .

[34]  B. Hager,et al.  Subduction zone dip angles and flow driven by plate motion , 1978 .

[35]  J. Harper.  Asthenosphere flow and plate motions , 1978 .

[36]  Bryan L. Isacks,et al.  Geometry of the subducted lithosphere beneath the Banda Sea in eastern Indonesia from seismicity and fault plane solutions , 1978 .

[37]  D. Karig,et al.  Characteristics of back arc spreading in the Mariana Trough , 1978 .

[38]  C. G. Chase.  Plate kinematics: The Americas, East Africa, and the rest of the world , 1978 .

[39]  F. Richter,et al.  Simple plate models of mantle convection , 1977 .

[40]  Thomas H. Jordan,et al.  Present‐day plate motions , 1977 .

[41]  T. Tullis,et al.  Evaluation of the forces that drive the plates , 1977 .

[42]  G. Davies.  Whole-mantle convection and plate tectonics , 1977 .

[43]  S. Uyeda,et al.  Evolution of the western pacific and its margin , 1977 .

[44]  Richard J. O'Connell,et al.  On the scale of mantle convection , 1977 .

[45]  D. Clague,et al.  Implications of Pacific Island and Seamount Ages for the Origin of Volcanic Chains (Paper 6R0694) , 1977 .

[46]  B. Isacks,et al.  Spatial distribution of earthquakes and subduction of the Nazca plate beneath South America , 1976 .

[47]  E. Thompson,et al.  Finite element models for creeping convection , 1976 .

[48]  Z. Garfunkel.  Growth, shrinking, and long‐term evolution of plates and their implications for the flow pattern in the mantle , 1975 .

[49]  Donald W. Forsyth,et al.  On the Relative Importance of the Driving Forces of Plate Motion , 1975 .

[50]  P. Molnar,et al.  Cenozoic Tectonics of Asia: Effects of a Continental Collision: Features of recent continental tectonics in Asia can be interpreted as results of the India-Eurasia collision. , 1975, Science.

[51]  W. M. Kaula.  Absolute plate motions by boundary velocity minimizations , 1975 .

[52]  L. Lliboutry.  Plate movement relative to rigid lower mantle , 1974, Nature.

[53]  S. Solomon,et al.  Some simple physical models for absolute plate motions , 1974 .

[54]  N. Weiss,et al.  Convection in the earth's mantle: towards a numerical simulation , 1974, Journal of Fluid Mechanics.

[55]  F. Richter.  Dynamical Models for Sea Floor Spreading , 1973 .

[56]  D. Clague,et al.  Tertiary Pacific Plate Motion Deduced from the Hawaiian-Emperor Chain , 1973 .

[57]  K. Burke,et al.  Two Types of Mountain Building , 1972, Nature.

[58]  T. Fitch.  Plate convergence, transcurrent faults, and internal deformation adjacent to Southeast Asia and the western Pacific , 1972 .

[59]  P. Barker.  A spreading centre in the east Scotia sea , 1972 .

[60]  W. J. Morgan,et al.  Plate Motions and Deep Mantle Convection , 1972 .

[61]  D. Turcotte,et al.  Structure of the olivine‐spinel phase boundary in the descending lithosphere , 1971 .

[62]  D. Karig.  Origin and development of marginal basins in the western Pacific , 1971 .

[63]  Walter M. Elsasser,et al.  Sea‐Floor Spreading as Thermal Convection , 1971 .

[64]  P. Molnar,et al.  Distribution of stresses in the descending lithosphere from a global survey of focal‐mechanism solutions of mantle earthquakes , 1971 .

[65]  Donald L. Turcotte,et al.  Finite amplitude convective cells and continental drift , 1967, Journal of Fluid Mechanics.

[66]  J. Wilson,et al.  Evidence from Islands on the Spreading of Ocean Floors , 1963, Nature.