Modeling interseismic deformation field of North Tehran Fault extracted from precise leveling observation

- Study of the interseismic deformation of the North Tehran Fault zone (NFT).
- NTF is a reverse fault posing a major threat to the city of Tehran.
- Fault parameters estimated by inverting leveling data from 1997 and 2005.
- The east NFT segment is creeping (~ 2 mm/year) while the western segment is slipping (~ 6 mm/year).

The North Tehran Fault (NTF) stands out as a major active thrust fault running for approximately 110 km north of Tehran, the capital province of Iran. It has been the source of several major historical earthquakes in the past, including those in 958, 1665, and 1830. In this paper, interseismic strain accumulation on the NFT was investigated using precise leveling measurements obtained over the time frame 1997-2005. The relationship between surface deformation field and interseismic deformation models was evaluated using simulated annealing optimization in a Bayesian framework. The results show that the NTF fault follows an elastic dislocation model creep at a rate of 2.5 ± 0.06 mm/year in the eastern part and 6.2 ± 0.04 mm/year in the western part. Moreover, the locking depth of the fault was evaluated to be ± 1.1 km in the eastern part and 1.3 ± 0.2 km in the western part.