[EN] The El Salvador Fault Zone, firstly identified after the 13th February 2001 Mw 6.6 El Salvador earthquake, is a 150 km long, 20 km wide\udright-lateral strike-slip fault system. Ruptures along the ESFZ are thought to be responsible for most of the historical destructive earthquakes\udalong the El Salvador Volcanic Arc, as well as for most of the current seismicity of the area. In this work, we focus on the geological\udsetting of the fault zone by describing its geomorphology and structure, using field-based observations, digital terrain modelling, and aerial\udphotograph interpretation with the aim at contributing to the understanding of the ESFZ slip behaviour. In particular, we address the ESFZ\udstructure, kinematics and evolution with time.\udThe ESFZ is a complex set of traces divided in major rupture segments characterized by different geometry, kinematics and geomorphic\udexpressions. Natural fault exposures and paleoseismic trenches excavated along the fault show that the strike-slip deformation is distributed\udin several planes. Both geometry and kinematics of the fault zone are consistent with a transtensional strain regime.\udThe estimated geological slip rate for the main fault segments by paleoseismic trenches and displaced geomorphic features implies a\uddeficit in velocity of the fault compared to the available GPS velocities data. The high vertical scarps of some fault segments would require\udQuaternary slip rates not coherent neither with measured GPS velocities nor with slip rates obtained from paleoseismic analysis. This mismatch\udsuggests a pre-existing graben structure that would be inherited from the previous regional roll back related extensional stage. We\udconsider that the ESFZ is using this relict structure to grow up along it. As a result, we propose a model for ESFZ development consistent\udwith all these observations.
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