Ancient Iranian Earthquakes: Chehr-Abad Salt Mine

Modern plate tectonic theory, the development of earthquake prediction and the mitigation of earthquake hazards are based on the study of earthquakes during the twentieth century. Investigation of earthquakes over a much longer period, although in no way invalidating the global importance of plate tectonics, shows that patterns of seismic activity do change with time and that areas of intense seismic activity in the historical past are often gaps of earthquake activity today. This study of the historical seismicity of Iran over the last thirteen centuries not only shows this quite clearly but also reveals a long-term tectonic pattern which is different from that deduced from short-term observations. The historical data provides the basis for the development of earthquake prediction models and for long-term earthquake hazard assessment. The Chehr-Abad salt mine, near Hamzehloo in Zanjan Province, Iran, has produced some remarkable evidence for the extraction of salt from at least the mid-first millennium. In addition to the large quantities of textile, wood, and food remains from the site, six human ‘‘mummies’’ have been recovered. Three are largely skeletonized assemblages of partially articulated human bone (Mummies no. 2, 3, and 5), but with some soft tissue, hair, and teeth remaining. There are some historical remarks concerning the occurrence of an earthquake, which might shed lights on reasons behind the entrapment of mine workers in Chehr-Abad Salt Mine.