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pure and applied geophysics

, Volume 140, Issue 2, pp 211–255 | Cite as

Quantitative estimates of interplate coupling inferred from outer rise earthquakes

  • Xinping Liu
  • Karen C. McNally
Article

Abstract

Interplate coupling plays an important role in the seismogenesis of great interplate earthquakes at subduction zones. The spatial and temporal variations of such coupling control the patterns of subduction zone seismicity. We calculate stresses in the outer rise based on a model of oceanic plate bending and coupling at the interplate contact, to quantitatively estimate the degree of interplate coupling for the Tonga, New Hebrides, Kurile, Kamchatka, and Marianas subduction zones. Depths and focal mechanisms of outer rise earthquakes are used to constrain the stress models. We perform waveform modeling of body waves from the GDSN network to obtain reliable focal depth estimates for 24 outer rise earthquakes. A propagator matrix technique is used to calculate outer rise stresses in a bending 2-D elastic plate floating on a weak mantle. The modeling of normal and tangential loads simulates the total vertical and shear forces acting on the subducting plate. We estimate the interplate coupling by searching for an optimal tangential load at the plate interface that causes the corresponding stress regime within the plate to best fit the earthquake mechanisms in depth and location.

We find the estimated mean tangential load\(\overline f _x\) over 125–200 km width ranging between 166 and 671 bars for Tonga, the New Hebrides, the Kuriles, and Kamchatka. This magnitude of the coupling stress is generally compatible with the predicted shear stress at the plate contact from thermal-mechanical plate models byMolnar andEngland (1990), andVan den Buekel andWortel (1988). The estimated tectonic coupling,F tc , is on the order of 1012–1013 N/m for all the subduction zones.F tc for Tonga and New Hebrides is about twice as high as in the Kurile and Kamchatka arcs. The corresponding earthquake coupling forceF ec appears to be 1–10% of the tectonic coupling from our estimates. There seems to be no definitive correlation of the degree of seismic coupling with the estimated tectonic coupling. We find that outer rise earthquakes in the Marianas can be modeled using zero tangential load.

Key words

Interplate coupling outer rise earthquakes stress modeling subduction zones 

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References

  1. Bevington, P. R.,Data Reduction and Error Analysis for the Physical Sciences (McGraw-Hill Book Company, 1969).Google Scholar
  2. Burbach, G. V., andFrohlich, C. (1986),Intermediate and Deep Seismicity and Lateral Structure of Subducted Lithosphere in the Circum-Pacific Region, Rev. Geophys.24, 833–874.Google Scholar
  3. Caldwell, J. G., Haxby, W. F., Karig, D. E., andTurcotte, D. L. (1976),On the Applicability of a Universal Elastic Trench Profile, Earth Planet. Sci. Lett.31, 239–246.Google Scholar
  4. Cathles, L. M. III The Viscosity of the Earth's Mantle (Princeton University Press, 1975).Google Scholar
  5. Chapple, W. M., andForsyth, D. W. (1979),Earthquakes and Bending of Plates at Trenches, J. Geophys. Res.84, 6729–6749.Google Scholar
  6. Chen, T., andForsyth, D. W. (1978),A Detailed Study of Two Earthquakes Seaward of the Tonga Trench: Implications for Mechanical Behavior of the Oceanic Lithosphere J. Geophys. Res.83, 4995–5003.Google Scholar
  7. Chen, W.-P., andMolnar, P. (1983), Focal Depths of Intracontinental and Intraplate Earthquakes and their Implications for the Thermal and Mechanical Properties of the Lithosphere, J. Geophys. Res.88, 4183–4214.Google Scholar
  8. Choy, G. L. andDewey, J. W. (1988),Rupture Process of an Extended Earthquake Sequence: Teleseismic Analysis of Chilean Earthquake of March 3, 1985, J. Geophys. Res.93, 1103–1118.Google Scholar
  9. Christensen, D. H., andLay, T. (1988),Large Earthquakes in the Tonga Region Associated with Subduction of the Louisville Ridge, J. Geophys. Res.93, 13,367–13,389.Google Scholar
  10. Christensen, D. H., andRuff, L. J. (1988),Seismic Coupling and Outer-rise Earthquakes, J. Geophys. Res.93, 13,421–13,444.Google Scholar
  11. Christensen, D. H., andRuff, L. J. (1983),Outer Rise Earthquakes and Seismic Coupling, Geophys. Res. Lett.10, 697–700.Google Scholar
  12. Das, S., andScholz, C. H. (1983),Why Large Earthquakes do not Nucleate at Shallow Depths, Nature305, 621–623.Google Scholar
  13. Davies, G. F. (1980),Mechanics of Subducted Lithosphere, J. Geophys. Res.85, 6304–6318.Google Scholar
  14. Dmowska, R., andLovison, L. C. (1992),Influence of Asperities along Subduction Interfaces on the Stressing and Seismicity of Adjacent Areas, Tectonophysics211, 23–43.Google Scholar
  15. Dmowska, R., Rice, J. R., Lovison, L. C., andJosell, D. (1988),Stress Transfer and Seismic Phenomena in Coupled Subduction Zones during the Earthquake Cycle, J. Geophys. Res.93, 7869–7884.Google Scholar
  16. Dziewonski, A. M., andAnderson, D. L. (1981)Preliminary Reference Earth Model (PREM), Phys. Earth Planet. Inter.25, 297–356.Google Scholar
  17. Dziewonski, A. M., Ekström, G., Franzen, J. E., andWoodhouse, J. H. (1988),Global Seismicity of 1981: Centroid-moment Tensor Solutions for 542 Earthquakes, Phys. Earth Planet. Inter.50, 155–182.Google Scholar
  18. Forsyth, D. W. (1982),Determinations of Focal Depths of Earthquakes Associated with the Bending of Oceanic Plates at Trenches, Phys. Earth Planet. Inter.28, 141–160.Google Scholar
  19. Giardini, D., andWoodhouse, J. H. (1984),Deep Seismicity and Modes of Deformation in Tonga Subduction Zone, Nature307, 505–509.Google Scholar
  20. Hasebe, K., Fujii, N., andYueda, S. (1970),Thermal Processes under Island Arcs, Tectonophysics10, 335–355.Google Scholar
  21. Heaton, T. H. (1990),Evidence for and Implications of Self-healing Pulses of Slip in Earthquake Rupture, Phys. Earth Planet. Inter.64, 1–20.Google Scholar
  22. Isacks, B. L., andBarazangi, M. (1977),Geometry of Benioff Zones: Lateral Segmentation and Downwards Bending of Subducted Lithosphere, Island Arcs, Deep Sea Trenches and Back-arc Basins, Maurice Ewing Series1, 99–114.Google Scholar
  23. Isacks, B. L., andMolnar, P. (1969),Mantle Earthquake Mechanisms and the Sinking of the Lithosphere, Nature223, 1121–1124.Google Scholar
  24. Jaeger, J. C., andCook, N. G. W.,Fundamentals of Rock Mechanics (London: Chapman and Hall, 1979).Google Scholar
  25. Jarrard, R. D. (1986),Relations among Subduction Parameters, Rev. Geophys.24, 217–284.Google Scholar
  26. Kagan, Y. Y., andJackson, D. D. (1991a),Long-term Earthquake Clustering, Geophys. J. Int.104, 117–133.Google Scholar
  27. Kagan, Y. Y., andJackson, D. D. (1991b),Seismic Gap Hypothesis: Ten Years After, J. Geophys. Res.96, 21,419–21,431.Google Scholar
  28. Kanamori, H. (1977),The Energy Release in Great Earthquakes, J. Geophys. Res.82, 2981–2987.Google Scholar
  29. Kelleher, J., Savino, J., Rowlett, H., andMcCann, W. (1974),Why and Where Great Thrust Earthquakes Occur along Island Arcs, J. Geophys. Res.79, 4889–4899.Google Scholar
  30. Lay, T., Astiz, L., Kanamori, H., andChristensen, D. H. (1989),Temporal Variation of Large Intraplate Earthquakes in Coupled Subduction Zones, Phys. Earth Planet. Inter.54, 258–312.Google Scholar
  31. Lay, T., Kanamori, H., andRuff, L. J. (1982),The Asperity Model and the Nature of Large Subduction Zone Earthquakes, Earthq. Pred. Res.1, 3–71.Google Scholar
  32. Molnar, P., andEngland, P. (1990),Temperatures, Heat Flux and Frictional Stress near Major Thrust Faults, J. Geophys. Res.95, 4833–4856.Google Scholar
  33. Ruff, L. J. (1989),Do Trench Sediments Affect Great Earthquake Occurrence in Subduction Zones? Pure and Appl. Geophys.129, 263–282.Google Scholar
  34. Ruff, L. J. andKanamori, H. (1983),Seismic Coupling and Uncoupling at Subduction Zones, Tectonophysics99, 99–117.Google Scholar
  35. Ruff, L. J., andKanamori, H. (1980),Seismicity and the Subduction Process, Phys. Earth Planet. Inter.23, 240–252.Google Scholar
  36. Scholl, D. W., Van Huene, R., andDieffenback, H. L. (1990),Rates of Sediment Subduction Erosion-Implications for Growth of Terrestrial Crust (abs.), EOS, Trans. AGU71, 1576.Google Scholar
  37. Schwartz, S. Y., Dewey, J. W., andLay, T. (1989),Influence of Fault Plane Heterogeneity on the Seismic Behavior in the Southern Kurile Islands Arc, J. Geophys. Res.94, 5637–5649.Google Scholar
  38. Spence, W. (1987),Slab Pull and the Seismotectonics of Subducting Lithosphere, Rev. Geophys.25, 55–69.Google Scholar
  39. Stauder, W. (1973),Mechanisms and Spatial Distribution of Chilean Earthquakes with Relation to Subduction of Oceanic Plate. J. Geophys. Res.78, 5033–5061.Google Scholar
  40. Stauder, W. (1968a),Mechanism of the Rat Island Earthquake Sequence of February 4, 1965, with Relation to Island Arcs and Sea-floor Spreading, J. Geophys. Res.73, 3847–3858.Google Scholar
  41. Stauder, W. (1968b),Tensional Character of Earthquake Foci Beneath the Aleutian Trench with Relation to Sea Floor Spreading, J. Geophys. Res.73, 7693–7701.Google Scholar
  42. Tajima, F., andKanamori, H. (1985),Global Survey of Aftershock Area Expansion Patterns, Phys. Earth Planet. Inter.40, 77–134.Google Scholar
  43. Toksöz, M. N., Minear, J. W., andJulian, B. P. (1971),Temperature Field and Geophysical Effects of a Downgoing Slab, J. Geophys. Res.76, 1113–1138.Google Scholar
  44. Toksöz, M. N., Sleep, N. H., andSmith, A. T. (1973),Evolution of the Downgoing Lithosphere and the Mechanisms of Deep Focus Earthquakes, Geophys. J. R. Astr. Soc.35, 285–310.Google Scholar
  45. Turcotte, D. L., McAdoo, D. C., andCaldwell, J. G. (1978),An Elastic-Perfectly Plastic Analysis of the Bending in the Lithosphere at a Trench, Tectonophysics47, 193–206.Google Scholar
  46. Turcotte, D. L., andSchubert, G.,Geodynamics: Applications of Continuum Physics to Geological Problems (John Wiley and Sons, 1982).Google Scholar
  47. Uyeda, S., andKanamori, H. (1979),Back-arc Opening and the Mode of Subduction, J. Geophys. Res.84, 1049–1061.Google Scholar
  48. Van den Buekel, J., andWortel, R. (1988),Thermo-mechanical Modeling of Arc-trench Regions, Tectonophysics154, 177–193.Google Scholar
  49. Ward, S. N. (1984),A Note on Lithospheric Bending Calculations, Geophys. J. R. Astr. Soc.78, 241–253.Google Scholar
  50. Ward, S. N. (1983),Body Wave Inversion: Moment Tensors and Depths of Oceanic Intraplate Bending Earthquakes, J. Geophys. Res.88, 9315–9330.Google Scholar
  51. Watts, A. B., Bodine, J. H., andSteckler, M. S. (1980),Observations of Flexure and the State of Stress in the Oceanic Lithosphere, J. Geophys. Res.85, 6369–6376.Google Scholar
  52. Wiens, D. A., andStein, S. (1983),Age Dependence of Oceanic Intraplate Seismicity and Implications for Lithospheric Evolution, J. Geophys. Res.88, 6455–6468.Google Scholar
  53. Willemann, R. J. (1991),Stress Propagation and Strain Rate in Subducted Lithosphere, J. Geophys. Res.96, 10,219–10,232.Google Scholar
  54. Yokokura, T. (1981),Viscosity of the Earth's Mantle: Inference from Dynamic Support by Flow Stress, Tectonophysics77, 35–62.Google Scholar
  55. Zhang, J., andLay, T. (1992),The April 5, 1990 Mariana Islands Earthquake and Subduction Zone Stresses, Phys. Earth Planet. Inter.72, 99–121.Google Scholar
  56. Zhang, J., Hager, B. H., andRaefsky, A. (1985),Critical Assessment of Viscous Models of Trench Topography and Corner Flow, Geophys. J. R. Astr. Soc.83, 451–475.Google Scholar
  57. Zhou, H.-W. (1990),Observations on Earthquake Stress Axes and Seismic Morphology of Deep Slabs, Geophys. J. Int.103, 377–401.Google Scholar

Copyright information

© Birkhäuser Verlag 1993

Authors and Affiliations

  • Xinping Liu
    • 1
  • Karen C. McNally
    • 1
  1. 1.C. F. Richter Seismological Laboratory and Institute of TectonicsUniversity of California, Santa CruzSanta CruzUSA

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