Abstract
The September 24, 1999 Ahram Earthquake in southwestern Iran was moderate in energy (M = 5.0–5.5 from different sources) and did not entail significant destruction and casualities. The tectonic position of the source zone, surficial seismic dislocations, and results of macroseismic and seismological study of this seismic event in the junction zone of the Zagros Fold System and the piedmont plain are described in the paper, including data on rejuvenated ancient ruptures exposed in two trenches excavated across the strike of the regional Kazerun-Borazjan Fault. One of the trenches was driven a few months before and the other a year after this seismic event. The conclusion is drawn that new deformations in the Quaternary near-surface sediments observed at the walls of both trenches may be regarded as unusual seismic ruptures of the Ahram earthquake. These ruptures, described as proved primary seismic dislocations of such a moderate seismic event, are a unique phenomenon in the world seismotectonic practice. The localization of the earthquake source zone in the Kazerun-Borazjan Fault Zone with complex kinematics makes it possible to study the internal structure of one of the most important tectonic lines of the Zagros Fold Region.
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Original Russian Text © E.A. Rogozhin, 2012, published in Geotektonika, 2012, Vol. 46, No. 5, pp. 63–74.
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Rogozhin, E.A. Seismotectonic features of the September 24, 1999 Ahram earthquake in the Zagros, Iran. Geotecton. 46, 369–378 (2012). https://doi.org/10.1134/S0016852112050044
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DOI: https://doi.org/10.1134/S0016852112050044