Although the Dead Sea Transform fault system has been extensively studied in the past, little has been known about the present-day kinematics of its southernmost portion that is offshore in the Gulf of Aqaba. Here we present a new GPS velocity field based on three surveys conducted between 2015 and 2019 at 30 campaign sites, complemented by 11 permanent stations operating near the gulf coast. Interseismic models of strain accumulation indicate a slip rate of 4.9+0.9−0.6 mm/yr and a locking depth of 6.8+3.5−3.1 km in the gulf’s northern region. Our results further indicate an apparent reduction of the locking depth from the inland portion of the Dead Sea Transform towards its southern junction with the Red Sea rift. Our modelling results reveal a small systematic left-lateral residual motion that we postulate is caused by, at least in part, late postseismic transient motion from the 1995 MW7.2 Nuweiba earthquake. Estimates of the moment accumulation rate on the main faults in the gulf, other than the one that ruptured in 1995, suggest that they might be near the end of their current interseismic period, implying elevated seismic hazard in the gulf area.
KAUST Repository Item: Exported on 2021-08-30
Acknowledged KAUST grant number(s): OSR-2016-CRG5-3027
Acknowledgements: We thank Hannes Vasyura-Bathke, Joël Ruch, Jon Harrington, Samer Almashharawi, Mohammad Youssof, Laura Parisi, Adel Sherif and the students of the 2015 Seismotectonics course at KAUST for the help with the GPS fieldwork campaigns. We also thank the Saudi Geological Survey (SGS) and King Abdulaziz city for Science and Technology (KACST) for providing the continuous GPS data from the gulf’s stations. Maps were generated using the Generic Mapping Tools, Version 5.4.5 (Wessel et al. 2013, https://www.generic-mapping-tools.org). This research was supported by King Abdullah University of Science and Technology (KAUST), under award number OSR-2016-CRG5-3027.
- Geochemistry and Petrology