HIGH-RESOLUTION SEISMICITY IN SOUTH-CENTRALALBORZ USING INTEGRATED SEISMIC DATA

A comprehensive and high-resolution seismicity analysis is presented by integrating data from allpermanent and temporary seismic networks in the South-Central Alborz region. The dataset comprisesmore than ۲۵K local earthquakes, along with ۴۳ high quality focal mechanisms. We evaluated theperformance of four location programs: Hypo۷۱, Hypoellipse, NLLOC, and HypoDD. HypoDDdemonstrated superior performance based on statistical evaluations and good fitting of alignments ofseismicity with fault trends on map and cross-sections. The seismicity, in conjunction with focalmechanisms, offers a more detailed view of the well-known faults, brings to light less-known ones,and reveals complex patterns of seismic activities in different parts of the region. We introduce thecausative faults of the ۲۰۱۷ Malard ۴.۸Mw earthquake, the high activity of the Pardis and the Sorkhehfaults as significant faults, akin to Mosha in eastern Tehran. A new vertical strike-slip fault is definedwithin ۵ km west of Damavand.

Keywords:

Seismicity Study , Earthquake Relocation , Focal Mechanism , Cross-Section , CentralAlborz