On the elastic-perfectly plastic bending of the lithosphere under generalized loading with application to the Kuril Trench

Summary. The bending of the lithosphere as it approaches an oceanic trench is modelled using an elastic-perfectly plastic rheology. The rock within the elastic lithosphere is assumed to behave elastically until a yield stress is reached; for larger strains the stress is assumed to remain at the yield value (no strain hardening). The deflection of the lithosphere is obtained numerically for a range of applied moments, vertical forces and horizontal forces at the trench axis. The results of the analysis are compared with a series of topographic and gravity profiles across the Kuril Trench. In order to model the large observed curvatures of the lithosphere on the outer trench slope plasticity is required. The location of the region of high curvatures gives a value for the compressive axial load. One conclusion is that the lithosphere is under compression seaward of the Kuril Trench.

[1]  J. G. Caldwell,et al.  An elastic-perfectly plastic analysis of the bending of the lithosphere at a trench , 1978 .

[2]  J. D. Bremaecker.  Is the oceanic lithosphere elastic or viscous , 1977 .

[3]  B. Heezen,et al.  Visual Observations of the Sea Floor Subduction Line in the Middle-America Trench , 1977, Science.

[4]  D. Turcotte,et al.  Thermal and Mechanical Evolution of the Michigan Basin , 1976 .

[5]  J. G. Caldwell,et al.  On the applicability of a universal elastic trench profile , 1976 .

[6]  J. R. Cochran,et al.  Gravity Anomalies and Flexure of the Lithosphere along the Hawaiian-Emperor Seamount Chain , 1974 .

[7]  M. L. Sbar,et al.  Intraplate Earthquakes, Lithospheric Stresses and the Driving Mechanism of Plate Tectonics , 1973, Nature.

[8]  R. Huene.  Structure of the Continental Margin and Tectonism at the Eastern Aleutian Trench , 1972 .

[9]  T. Hanks.  The Kuril Trench ‐ Hokkaido Rise System: Large Shallow Earthquakes and Simple Models of Deformation , 1971 .

[10]  R. Walcott,et al.  Flexural rigidity, thickness, and viscosity of the lithosphere , 1970 .

[11]  M. Ewing,et al.  Sediments and structure of the Japan Trench , 1966 .

[12]  H. C. Heard,et al.  Chapter 4: Deformation of Rocks at 500° to 800° C. , 1960 .

[13]  P. Molnar,et al.  The Origin of Outer Topographic Rises Associated with Trenches , 1958 .

[14]  R. Gunn.  Quantitative aspects of juxtaposed ocean deeps, mountain chains, and volcanic ranges , 1947 .

[15]  M. Talwani,et al.  Gravity Anomalies Seaward of Deep-Sea Trenches and their Tectonic Implications* , 1974 .

[16]  L. Kachanov,et al.  Fundamentals of the Theory of Plasticity , 1974 .

[17]  W. Prager,et al.  Theory of perfectly plastic solids , 1968 .