A viscoelastic coupling model for the cyclic deformation due to periodically repeated Earthquakes at subduction zones

摘要: Vertical displacements due to periodic reverse faulting events in an elastic plate overlying a viscoelastic (Maxwell) half space are obtained and compared with the observed deformation cycle (coseismic strain release, postseismic transients, interseismic accumulation) from Japan. The effects, including influence of buoyant restoring forces, using method developed by Rundle, convergence accumulation incorporated following procedure suggested Savage. resulting is that analogous half-space dislocation model which postearthquake effects transient aseismic slip below coseismic fault. Cyclic similar but not identical for two models, observations southwest Japan suggest superiority coupling model. In particular, inclusion steady state flow asthenosphere overcomes defect results agreement movement pattern. Several aspects deformation, its landward migration, transition phase explained as well, short duration near-trench transients relative those farther inland matched. success buried explaining early movements asthenospheric accounting cumulative motions suggests existence zone between lithosphere whose behavior brittle/elastic term ductile longer-term such modification may reconcile remaining discordant observations. However, reasonable variations parameters cannot account differences other parts Japan, these regional remain unexplained.