Abstract

During the last fifteen years, the Gulf of Aqabah has been considered as one of the most seismically active zones in the Middle East region. A catalogue of 1415 events were compiled using the available data from the Seismic Studies Center Network, King Saud University and the adjacent neighboring networks. The data cover the time span that started from 1985 to 1995 and an area located between latitudes 28 to 30° N, and longitudes 34 to 36°E. The duration magnitudes for these earthquakes are equal to or greater than 2.8. The value of b in the Gutenberg-Richter relation for a local earthquakes catalogue was investigated. The maximum likelihood method was used in this study. Theb-value has apparently increased sharply (1.46 ± 0.21) before the mainshock-aftershock sequence type that is accompanied by a period of quiescence. Also, the b-value was moderate and steadily increased (0.98 ± 0.14) before the foreshock-mainshock-aftershock sequence type. Monitoring results suggest that b-value temporal variation may be an effective method for predicting earthquakes in the area of interest.

Key words: Gulf of Aqabah, b-value, magnitude frequency relation, seismicity, statistical calculation.