Viscoelastic Flow in the Lower Crust after the 1992 Landers, California, Earthquake

Jishu Deng, Michael Gurnis, Hiroo Kanamori, & Egill Hauksson

Published November 27, 1998, SCEC Contribution #446

Space geodesy showed that broad-scale postseismic deformation occurred after the 1992 Landers earthquake. Three-dimensional modeling shows that afterslip can only explain one horizontal component of the postseismic deformation, whereas viscoelastic flow can explain the horizontal and near-vertical displacements. The viscosity of a weak, about 10-km-thick layer, in the lower crust beneath the rupture zone that controls the rebound is about 1018 pascal seconds. The viscoelastic behavior of the lower crust may help to explain the extensional structures observed in the Basin and Range province and it may be used for the analysis of earthquake hazard.

Citation
Deng, J., Gurnis, M., Kanamori, H., & Hauksson, E. (1998). Viscoelastic Flow in the Lower Crust after the 1992 Landers, California, Earthquake. Science, 282(5394), 1689-1692. doi: 10.1126/science.282.5394.1689.