A tectonically loaded margin: brittle slopes and two millennia of seismically triggered failure in the Gulf of Aqaba

The Gulf of Aqaba lies along the central segment of the Dead Sea Transform and is capable of generating large-magnitude earthquakes and tsunamis, as demonstrated by the Mw 7.3 Nuweiba event in 1995. Yet the long-term recurrence behavior of such hazards remains poorly constrained. Here we show that anoxic deep-sea brine pools in the NEOM–northern Red Sea region preserve an exceptional stratigraphic record of earthquake-triggered sediment gravity flows, providing a continuous, high-resolution archive of paleoseismicity extending over the last two millennia.

High-resolution bathymetry, submersible observations, and numerical landslide–tsunami modeling reveal widespread incipient slope failure along the Pleistocene lowstand margin in the Tiran Straits and adjacent Gulf of Aqaba, indicating that laterally extensive weak layers are poised to fail during even moderate ground shaking. Laminated sediments recovered from the NEOM brine pool contain a sequence of seismoturbidites that correlate with all major historical earthquakes in the Gulf of Aqaba (1068, 1212, 1588, 1839, 1995 CE), as well as additional pre-instrumental events, implying a mean recurrence interval of order ~10^2 years. Comparison with historical intensity data suggests that peak ground accelerations as low as ∼0.05 g are sufficient to trigger basin-wide mass wasting and, in some cases, tsunamigenic slope failure.

These results demonstrate that deep-sea brine pools act as natural seismographs, recording both local and regional rupture of the Dead Sea Transform with a fidelity unmatched by conventional onshore archives. The combination of mechanically unstable continental margins and low shaking thresholds implies that the Gulf of Aqaba is unusually susceptible to earthquake-induced slope failure and tsunami generation. Brine-pool paleoseismology therefore offers a powerful new framework for quantifying long-term seismic and tsunami hazard in rift-bounded basins and for placing recent extreme events into a robust geological context.