The ۲۳ and ۲۴ January ۲۰۲۲ Tabriz earthquakes (NW Iran): Seismological study and seismotectonic implication

The January ۲۳ and ۲۴, ۲۰۲۲ earthquakes (MN ۴.۴ and MN ۴.۲, respectively) struck the densely populated Tabriz region. This work aims to characterize these two earthquakes in order to contribute to the understanding of the seismotectonic context of the study area. The relocated epicenters are within the Tabriz pull-apart basin associated with the North Tabriz fault zone. We perform waveform inversion to estimate focal mechanism solutions of earthquakes using data from broadband stations. The focal mechanisms indicate right-lateral strike-slip faulting with a slight normal component for the first earthquake and normal faulting with a small strike-slip component for the second earthquake. The first earthquake occurred on the dextral fault rupturing an obliquely-slip normal fault located to the west of the dextral fault. Furthermore, the coulomb stress transfer modeling of the first earthquake predicts the triggering of the second earthquake of MN ۴.۲. The calculated mechanisms for both earthquakes indicate a dominant transtensional stress regime for the Tabriz basin.

Keywords:

ACTIVE TECTONICS , STRIKE-SLIP FAULTING , EARTHQUAKE INTERACTION , NORTH TABRIZ FAULT , NORTHWESTERN IRAN , TABRIZ