Neotectonics and paleoseismology of the North Tabriz Fault, Azerbaijan Region, Northwest Iran

Abstract

Structural characteristics and seismic parameters were investigated to reevaluate seismic hazards along the North Tabriz Fault (NTF). Field surveys and paleoseismology on the central segment of the fault, combined with dating of sedimentary units, document multiple surface-rupturing paleoearthquakes during the past 3.5 ka. The calculated moment magnitudes (Mw) for the identified paleoearthquakes range from 6.3 to 7.5, causing surface ruptures of ca. 50 km with a maximum slip per event of 5.7 ± 0.2 m. Kinematic GPS surveys on displaced geomorphic features, combined with the dating results indicate that the central segment of the NTF slips at a rate of 6.4 ± 0.5 mm.yr-1 over the past 7.5 ka. Fault orientations and scattered volcanic vents in Sahand Volcanic Complex (SVC) suggest that its configuration and evolution have been affected by the regional transpression.