Earthquake Hazard in the Tehran Region based on the Characteristic Earthquake Model

ABSTRACT

Tehran is the most vulnerable urban area in Iran. Here, the characteristic earthquake model for the major earthquakes was integrated with the background seismicity to conduct the PSHA. For a 2475-year return period earthquake, a maximum PGA of 725 cm/s² and a maximum PGV of 60 cm/s were estimated. In next step, the simulated ground motions of the North Tehran Fault (NTF) were applied directly into the PSHA. Due to the fault rupture directivity effect considered through the simulations, the maximum PGA and PGV were estimated 845 cm/s2 and 100 cm/s respectively for a 2475 year return period. If we change location of hypocenter in our simulations, the distribution of highest hazard region will also change.

KEYWORDS:

• Characteristic model
• Time-dependent Brownian Passage Time
• Peak ground acceleration
• Peak ground velocity
• PSHA
• Tehran

Acknowledgments

The authors thank M. Villani and M. Ordaz for kindly providing of CRISIS code, and N. Kheirdast for coding of some CRISIS input data.

Funding

This study was supported by the International Institute of Earthquake Engineering and Seismology (IIEES), Project No. 9611/592: “Time-dependent hazard in the Iranian Plateau, case study: Tehran region”. The Global Centroid Moment Tensor Project database, available at www.globalcmt.org/CMTsearch.html (last accessed December 2013), the Iranian Seismological Centre (IRSC) bulletin available at http://irsc.ut.ac.ir/bulletin.phb and the International Institute of Earthquake Engineering and Seismology (IIEES) website available at http://www.bhrc.ac.ir/portal/(last accessed December 2013) were searched for instrumental catalogs. The catalog prepared by Shahvar et al. (2013), has been used for earthquakes before 2012.

Notes

1. (Hessami, et al., 2003), (Gholipour, et al., 2008).

2. (Berberian, 1981), (Berberian, et al., 1993), (Wells & Coppersmith, 1994).

3. T: Thrust, LL: Left Lateral Strike Slip, RL: Right Lateral Strike Slip.

4. According to Paleoseismological researches mentioned inside the text.

5. (Nazari, et al., 2014).

6. (Berberian & Yeats, 2001).

7. (De Martini, et al., 1998).

8. (Berberian & Yeats, 1999).

9. (Ritz, et al., 2012).

10. (Majidi Niri, et al., 2010).

11. (Nazari, et al., 2009).

12. (Hessami, et al., 2003), (Gholipour, et al., 2008).

13. (Berberian, 1981), (Berberian, et al., 1993), (Wells & Coppersmith, 1994).

14. T: Thrust, LL: Left Lateral Strike Slip, RL: Right Lateral Strike Slip.

15. L. Ch. Eq. D: Last Characteristic Earthquake Date.

16. Ch.Dis: Characteristic Displacement, (Wells & Coppersmith, 1994).

17. S.R.Y: Slip Rate in Year.

18. Eq.R.I.: Earthquake Recurrence Interval.

19. (Berberian & Yeats, 2001).

20. (Berberian, 1981).

21. (Berberian & Yeats, 2001).

22. R_JB: Joyner–Boore distance.

23. R_RUP: rupture distance.

24. R_HYP: Hypocentral distance.

25. R_EPI: Epicentral distance.

Additional information

Funding

This study was supported by the International Institute of Earthquake Engineering and Seismology (IIEES), Project No. 9611/592: “Time-dependent hazard in the Iranian Plateau, case study: Tehran region”. The Global Centroid Moment Tensor Project database, available at www.globalcmt.org/CMTsearch.html (last accessed December 2013), the Iranian Seismological Centre (IRSC) bulletin available at http://irsc.ut.ac.ir/bulletin.phb and the International Institute of Earthquake Engineering and Seismology (IIEES) website available at http://www.bhrc.ac.ir/portal/(last accessed December 2013) were searched for instrumental catalogs. The catalog prepared by Shahvar et al. (2013), has been used for earthquakes before 2012.