TY  - JOUR
A1  - Li, Shaoyang
A1  - Moreno Switt, Marcos
A1  - Bedford, Jonathan
A1  - Rosenau, Matthias
A1  - Heidbach, Oliver
A1  - Melnick, Daniel
A1  - Oncken, Onno
T1  - Postseismic uplift of the Andes following the 2010 Maule earthquake
T2  - Geophysical research letters
N2  - Postseismic surface deformation associated with great subduction earthquakes is controlled by asthenosphere rheology, frictional properties of the fault, and structural complexity. Here by modeling GPS displacements in the 6 years following the 2010 M-w 8.8 Maule earthquake in Chile, we investigate the impact of heterogeneous viscosity distribution in the South American subcontinental asthenosphere on the 3-D postseismic deformation pattern. The observed postseismic deformation is characterized by flexure of the South America plate with peak uplift in the Andean mountain range and subsidence in the hinterland. We find that, at the time scale of observation, over 2 orders of magnitude gradual increase in asthenosphere viscosity from the arc area toward the cratonic hinterland is needed to jointly explain horizontal and vertical displacements. Our findings present an efficient method to estimate spatial variations of viscosity, which clearly improves the fitting to the vertical signal of deformation. Lateral changes in asthenosphere viscosity can be correlated with the thermomechanical transition from weak subvolcanic arc mantle to strong subcratonic mantle, thus suggesting a stationary heterogeneous viscosity structure. However, we cannot rule out a transient viscosity structure (e.g., power law rheology) with the short time span of observation.
Y1  - 2017
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/55308
SN  - 0094-8276
SN  - 1944-8007
VL  - 44
IS  - 4
SP  - 1768
EP  - 1776
PB  - American Geophysical Union
CY  - Washington
ER  -