Publication Date:
2024-01-19
Description:
In this work, we investigate the Mw 5.9 earthquake occurred on 7 November 2019 in the
East-Azerbaijan region, in northwestern Iran, which is inserted in the tectonic framework of the
East-Azerbaijan Plateau, a complex mountain belt that contains internal major fold-and-thrust belts.
We first analyze the Di erential Synthetic Aperture Radar Interferometry (DInSAR) measurements
obtained by processing the data collected by the Sentinel-1 constellation along ascending and
descending orbits; then, we invert the achieved results through analytical modelling, in order to better
constrain the geometry and characteristics of the seismogenic source. The retrieved fault model shows
a rather shallow seismic structure, with a center depth at about 3 km, approximately NE–SW-striking
and southeast-dipping, characterized by a left-lateral strike-slip fault mechanism (strike = 29.17 ,
dip = 79.29 , rake = 4.94 ) and by a maximum slip of 0.80 m. By comparing the inferred fault
with the already published geological structures, the retrieved solution reveals a minor fault not
reported in the geological maps available in the open literature, whose kinematics is compatible with
that of the surrounding structures, with the local and regional stress states and with the performed
field observations. Moreover, by taking into account the surrounding geological structures reported
in literature, we also use the retrieved fault model to calculate the Coulomb Failure Function at
the nearby receiver faults. We show that this event may have encouraged, with a positive loading,
the activation of the considered receiver faults. This is also confirmed by the distribution of the
aftershocks that occurred near the considered surrounding structures. The analysis of the seismic
events nucleated along the left-lateral strike-slip minor faults of the East-Azerbaijan Plateau, such as
the one analyzed in this work, is essential to improve our knowledge on the seismic hazard estimation
in northwestern Iran.
Description:
Published
Description:
1346
Description:
2T. Deformazione crostale attiva
Description:
3T. Sorgente sismica
Description:
JCR Journal
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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