While the shock was recorded by seismographs around the world, few of these stations were close enough to the scene to locate the epicenter with high accuracy, but with what information was available the instrumental location was determined to have been to the north-northwest of the Kasbah. Macroseismic observations (establishing the locations with the highest observed intensity) placed the epicenter about north of Yachech. A sequence of minor foreshocks preceded the main event. The first shock occurred on 23 February with an intensity of III or IV (Weak to Light) and on the day of the disaster, a more significant foreshock with an intensity of VI (Strong) caused alarm around the lunchtime hour..
