Originally published as: Diao, F., Wang, R., Wang, Y., Xiong, X., Walter, T. R. (2018): Fault behavior and lower crustal rheology inferred from the first seven years of postseismic GPS data after the 2008 Wenchuan earthquake. - Earth and Planetary Science Letters, 495, pp. 202—212. DOI: http://doi.org/10.1016/j.epsl.2018.05.020 Manuscript to be submitted to EPSL 1 Fault behaviour and lower crustal rheology inferred from the first seven years of 2 postseismic GPS data after the 2008 Wenchuan earthquake 3 4 Faqi Diaoa, Rongjiang Wangb*, Yuebing Wangc, Xiong Xionga and Thomas R. Walterb 5 a. Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan 430074, 6 China 7 b. GFZ German Research Centre for Geosciences, Telegrafenberg, D-14473 Potsdam, 8 Germany 9 c. National Earthquake Infrastructure Service, Beijing 100045, China 10 *Corresponding author: Rongjiang Wang (
[email protected]) 11 12 Abstract 13 Long-term and wide-area geodetic observations may allow identifying distinct postseismic 14 deformation processes following large earthquakes, and thus can reveal fault behaviour 15 and permit quantifying complexities in lithospheric rheology. In this paper, the first 7 16 years of GPS (Global Positioning System) displacement data following the 2008 Mw7.9 17 Wenchuan earthquake are used to study the relevant mechanisms of postseismic 18 deformation. Two simple models that consider either afterslip or viscoelastic relaxation as 19 the unitary mechanism of the postseismic deformation are tested at first. After analysing 20 the limitations and complementarity of these two separated models, a combined model 21 incorporating the two main mechanisms is presented.