Discovery of three earthquake faults in Iran

AN earthquake fault is a ground fracture formed in association with a shallow earthquake, usually by reactivation of a pre-existing geological fault. It can provide information about both the mechanism of seismic energy release during an earthquake and the accompanying regional strains. Until now only two such faults which have been adequately documented are known in Iran. These are associated with the Buyin Zara (1962) and the Dasht-e Bayaz (1968) earthquakes1–3. The Torud (1953) and the Ashkhabad (1948) earthquake4,5 (the latter in the USSR, just north of the Iranian frontier), were probably also accompanied by faulting, but complete documentation is lacking. Here, we describe three additional earthquake faults found during recent seismotectonic field studies in Iran. The earthquakes involved were at Selakhor (1909), Baghan-Germab (1929) and Salmas (1930). Figure 1 shows the location of the three faults and of the other known and probable faults already mentioned.