In the Qatar Trench, oriented perpendicular to the Arava Fault within the Yotvata Playa and just south of the Yotvata extensional step, Klinger et al. (2015) identify Event E8 as a major prehistoric rupture in the lower part of the trench sequence, younger than E9 and Esupp2 and older than E7. Evidence is restricted to the western fault zone of the trench and is expressed by a distinctive set of faults, most of them dipping westward, between MM1 and MM5, which tilted the layers of unit H. This deformation was not limited to simple cracking. Klinger et al. infer that the event also produced a substantial down-drop of the eastern compartment, creating accommodation space later filled by subhorizontal sediments preserved east of MM8 beneath unit G. In this respect, E8 stands out as one of the larger deformation events in the trench, involving both faulting and block rotation rather than only narrow cracks.

The faults associated with E8 terminate upward near the contact between units H and G, but that contact itself is not offset even though the lower layers are. Klinger et al. therefore conclude that the H-G contact is an erosional contact that postdates E8 rather than the true event horizon. Some E8 cracks were later reactivated by younger earthquakes and can be traced upward through higher levels, but their upper geometry differs from the original structure because later motion produced eastward-dipping fault traces. This overprinting complicates the reconstruction, yet the older westward-dipping geometry and the tilting of unit H remain the key indicators that E8 was a separate, substantial event.

Event E8 is also bracketed stratigraphically by a tilted liquefaction conduit between MM5 and MM6. Because that conduit was tilted together with all of unit H, it must predate E8. At the same time, the conduit rises higher than the cracks attributed to E9, demonstrating that it postdates E9. This helps place E8 above E9 and above the possible Esupp2 liquefaction conduit disturbance, while still below the better-defined E7 rupture at the H-G boundary. The result is a sequence in which E8 records a major episode of subsidence and tilting in the western fault zone, later followed by renewed rupture on overlapping fault traces.

Chronologically, E8 falls within the same broad prehistoric interval as E9 and Esupp2. Klinger et al. (2015) assign the E8–E9 sequence to a 2797–1245 BCE time window derived from a Bayesian model based on radiocarbon dates derived from detrital charcoal. They propose that E8 and E9 may represent a paired sequence, although the temporal spacing between the two events cannot be resolved with precision because of limited chronological control in the lower trench and the presence of an erosional hiatus at the H–G contact, which may have removed as much as ~700 years of the sedimentary archive. In their interpretation, E8 is emphasized, together with E4, as one of the two events marked by comparatively large vertical displacement, a pattern they attribute to rupture propagation through the Yotvata extensional step and potentially along a much longer segment of the Wadi Araba fault compared to the more localized, crack-dominated events. However, because E9 is interpreted as one of the fault ruptures that likely terminated at the Yotvata extensional step, its proposed pairing with E8, which is inferred to have propagated through this step, is internally inconsistent.

Figure 5 - Trench log of the southern wall. The full resolution photomosaic of the wall is available in Fig. S1. The different stratigraphic units are indicated by letters A to H located in the synthetic stratigraphic section. Conservative position of event horizons are indicated with a dashed line, including for event Esuppl unambiguously visible in the eastern fault zone only. E8 is indicated for reference, although the dashed line corresponds to E7 event horizon (see discussion in text). Esupp2, between E8 and E9 is not indicated. Meter Marks (MM) are indicated above the trench. Dated ¹⁴C samples are indicated by star. To the west, a few samples have been collected up to 2 m outside the gridded wall, where the layers could be traced horizontally. Samples are indicated at the corresponding depth and stratigraphic position. - Click on Image to open in a new tab - Klinger et al (2015)