Rapid Estimation of Peak Ground Velocity and Earthquake Location Using Small Magnitude Earthquakes in the Tehran Region, Iran

Abstract

Online Material: Supplemental tables. The Tehran metropolis is located in an extensive area between the Alborz mountain belt to the north and the central Iranian plateau to the south. Tehran, as the political and economic capital of Iran, is considered one of the most populated cities in the world. From the point of view of vulnerability to natural disasters, Tehran is of great concern because of its basic infrastructures and population concentration. The Alborz mountain belt is a part of the Himalayan–Alps orogenic belt with numerous active faults, including the Mosha reverse fault, the North Tehran thrust fault, the Parchin, the Kahrizak, and the South and North Rey faults, with high seismic potential in the study region (Fig. 1). The Mosha fault is one of the fundamental structures of the central Alborz mountains and is situated north of Tehran. This fault is concave to the north and extends from the edge of the mountain range in the west to the eastern Alborz mountains and can be considered an upthrust in some places and an overthrust in others (Moinfar et al. , 1994; Berberian and Yeats, 1999). The North Tehran fault is the most prominent tectonic structure in the immediate vicinity of Tehran for which the trace is east–west to east‐northeast–west‐southwest and slightly concave to the south (Berberian and Yeats, 1999). The Tehran urban district is extended across thick alluvium layers over bedrock with complex geological structure. Based on historic seismic documents, Tehran is surrounded by several specific faults with return periods of about 150 years, but no damaging earthquake has occurred since 1830 (Moinfar et al. , 1994; Berberian and Yeats, 1999), when an estimated 45,000 …