Matteo Basilici

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2-D finite element modeling of both coseismic and interseismic deformation was performed along a transect across the seismogenic fault of the Mw=7.3, November 2017 Lurestan earthquake (Zagros Mountains). In order to extract information on the time-space distribution of uplift along the same transect, an investigation of the large-scale features of topography and river network was also carried out. Constraints from the spatial distribution of mean elevation, local relief and normalized channel steepness index (ksn), combined with those from river longitudinal profiles and transformed river profiles (chi-plots), were integrated with the results of geomorphological analyses aimed at the reconstruction of the development of the fluvial network. Despite the much longer timescale over which topography grows and/or rivers respond to tectonic or climatic perturbations with respect to even multiple seismic cycles, the outputs of the finite element model yield fundamental information on the source of the late part of the spatiotemporal evolution of surface uplift recorded by the geomorphological signature. Model outputs shed new light into the processes controlling relief evolution in an actively growing mountain belt underlain by a major blind thrust. They point out how co-seismic slip controls localized uplift of a prominent topographic feature ­– defining the Mountain Front Flexure – located above the main upper crustal ramp of the principal basement thrust fault of the region, while continuous displacement along the deeper, aseismic portion of the same basement fault controls generalized uplift of the whole crustal block located further to the NE, in the interior of the orogen.