Abstract
Questions regarding the development of folds and their interactions with
the seismic faults within thrust systems remain unanswered. However,
estimating fault slip and earthquake hazards using surface observations
and kinematic models of folding requires an understanding of how the
shortening is accommodated during the different phases of the earthquake
cycle. Here, we construct 16-years of InSAR time series across the North
Qaidam thrust system (NE Tibet), where three Mw 6.3 earthquakes occurred
along basement faults underlying shortened folded sediments. The
analysis reveals spatio-temporal changes of post-seismic surface
displacement rates and patterns, which continue more than ten years
after the seismic events. The decomposition of the Sentinel-1 ascending
and descending LOS velocities into vertical and shortening post-seismic
components indicates that long-term transient uplift and shortening
coincide spatially with young anticlines observed in the geomorphology
and cannot simply be explained by elastic slip along dislocations. These
findings provide evidences for fold buckling during the post-earthquake
phase and highlight the contribution of distributed aseismic deformation
to the growth of topography.