than 500 local earthquakes (ML Q 4.85) occurred in the Gulf of Aqaba area between latitudes 29'00 ' and 29'25' and longitudes 34'30' and 34'45'. Most of the activity including the largest shocks was restricted t o the area between latitudes 29'07 ' and 29'15' and longitudes 34'33' and 34'42' where the NW Atiya regional dyke crosses the area and is horizontally displaced by NE strike-slip faults. The first-motion directions of four large shocks, including the largest, at both UNJ and HLW stations are in agreement with a strike-slip mechanism at a NE-trending fault in this area. The b value showed a temporal increase with time from 0.43 to 0.69. This, together with other geological and geophysical observations may indicate that subsurface magmatic activity has affected the stressed crustal rocks, thus triggering earthquake activity.This swarm and historical information indicate that the Gulf of Aqaba-Dead Sea Jordan transform is characterized by both swarm and foreshockaftershock types of seismic activity and therefore the relatively large proportion of non-seismic slip along the southern part of this transform may actually be higher if swarm-type activities are considered. IntroductionAn earthquake swarm occured in the Gulf of Aqaba area (Fig. l), in the period 1983 January 21 to April 20, during which 60 shocks (1.7 Q M L Q 4.85) were recorded on the Jordan University Seismological Station, some 350 km distant. With no distinctive main shock, the level of activity fluctuated with time, reaching its highest on February 3 when a few large shocks (including the largest of the swarm) occurred and were widely felt in the Saudi town of Haql, Aqaba and the surrounding region, thus causing panic and concern. On February 8, a temporary seismic station was installed near Haql. Within its 72 days of operation, more than 500 shocks (0.0 G M L G 3.5) were recorded, showing a decreasing level of activity with time. By April 20, the level of seismicity in the Gulf seemed to have returned to normal.