Source Parameters and Epicentral Relocation of The 22 June 2002 Avaj Earthquake

摘要

The Changoureh-Avaj earthquake of June 22nd 2002 is the largest shock since the occurrence of the 1962 Buyin-Zahra earthquake in Qazvin province. The ground-motion characteristics during the main shock should be considered for the high safety design of structures in the region. we calculated the ground motion parameters of this event using digital accelerograms Data of Building and Housing Research Center (BHRC) by using Seismosignal and Sigmaplot softwares. The earthquake was recorded by 78 digital accelerographs installed in different points of the area. We used 18 accelerograms which had good signal to noise ratios at a distance range of 26 - 100 km. The maximum acceleration recorded in this event so far is about 0.5g at the Avaj station which is situated 26km from the earthquake hypocentre. We relocated the epicentre of this event and the first 23 aftershocks by using Tehran Seismic Network Data and Hypoinverse Software. A focal depth of 7 km is estimated for the mainshock. Different seismological Agencies such as (IGTU, NEIC, HRVD) reported different location, in this study, results are consistent with the computation results.