A Database of Historical Earthquake Activity in the Middle East

The Middle East is one of the few regions on Earth where documentation of earthquake activity extends back over 4000 years. This documentation is in a wide range of forms, and includes Biblical, ecclesiastical and historical chronicles. During the present century meticulous work involving such data sources has yielded large amounts of information concerning historical earthquakes. These data, however, are often difficult to assess (particularly at the regional scale of study) and this has led to an over reliance in hazard assessments upon instrumentally recorded seismic data of the twentieth century. This paper describes a database of historical (pre-twentieth century) earthquake activity in the Middle East that has been compiled as the basis for a regional analysis of the hazard for insurance and reinsurance purposes. The use of a database system has provided a means of collating published historical data for the region and standardizing the information available for each earthquake event, thereby facilitating data analysis. The paper examines the structure and production of the database and presents a preliminary analysis of the data. This has highlighted numerous aspects of the earthquake hazard that are of particular relevance to existing and proposed developments in the region. These include the large areas affected by some offshore earthquakes, the ability of high magnitude onshore earthquakes to trigger submarine slumping and thence seismic sea waves in the eastern Mediterranean, the importance of building elevation in controlling exposure to the earthquake hazard, and variations in the seismic activity of some Middle Eastern countries through time (possibly indicative of interaction/fluctuation between some of the contiguous tectonic belts in the region). The work serves to demonstrate the value of regional databases to earthquake hazard assessment, and reiterates the many advantages of assimilating data in ordered database structures.