Re-examination of the historical 11 May, 1624 Fez earthquake parameters

Abstract

The 11 May 1624 Fez earthquake is one of the worst natural disasters in the history of Morocco, and caused serious damage in the city of Fez and its surroundings. It occurred in one of the most active seismic zones in the country, and in an area that is now densely populated. The 1624 earthquake occurred at a crucial time in the history of Morocco (decline of the Saadian dynasty and outbreak of internal wars) which explains the lack of sufficient information on the extensive devastation that resulted from the earthquake. We consulted several Moroccan and European sources, whenever possible first hand. A complete historical review of testimonies and journals of the time describing this particular earthquake has been carried out. Correlation these effects with the local geological setting and the most recent seismological data shows that the focal region of the 1624 Fez earthquake is likely to be located somewhere along the E—W trending Rides Prérifaines, the main frontal thrust of the Rif. An evaluation of the magnitude of the earthquake is proposed, on the basis of existing empirical relationships. Understanding this earthquake may improve the seismic hazard assessment of the region.