Event CH4-E3 - Modeled Age 250-310 CE Open this page in a new tab

At the deltaic site of Bet Zeyda (aka Beteiha), just north of the Sea of Galilee (aka Lake Kinneret), three-dimensional paleoseismic investigations were conducted by multiple researchers over a number of years using numerous trenches. The studies examined a series of ~E–W-oriented paleo-channels intersected and sinistrally displaced by the ~N–S-trending active Jordan Gorge Fault, producing a detailed chronology of fault activity over roughly the past 2,000 years, based on radiocarbon dating of detrital charcoal. Once outliers are excluded, this material appears to have a residence time of decades rather than centuries (e.g. see Marco et al., 2005:200). Results indicate that seismic events were more frequent and produced greater fault slip during the first millennium CE than in the second, suggesting the region may be approaching another period of heightened seismic activity.

Wechsler et al. (2014:9) identified six earthquakes in paleo-channel 4 (CH4). Wechsler et al. (2018:216) add that channel 4 crossed the fault in an area where a long, linear, and narrow pressure ridge is interpreted to have produced localized uplift east of the main fault, while subsidence to the west caused sediment thickening. Wechsler et al. (2014:13) found evidence for Event CH4-E3 primarily in Trench T39, although evidence was also identified in Trench T33. Event CH4-E3 is associated with multiple fault strands, some of which re-ruptured during later seismic events. Wechsler et al. (2014:13) also interpreted thickening of certain sedimentary units into "a shallow synclinal form" as a by-product of Event CH4-E3. Wechsler et al. (2014:13) further observed strata thinning and terminating against the fold scarp of a pressure ridge, which was interpreted as additional evidence of seismic deformation.

Wechsler et al. (2018:Table 3) date this event to 250–310 CE but were unable to estimate the offset associated with it. Dating is based on a Bayesian model of radiocarbon ages. Wechsler et al. (2014:14) note that "the strata between events CH4-E3 and CH4-E4 are only dated by a single [radiocarbon] sample".



Figure 8 - Trench logs for T39 (north and south walls). Event horizons are marked with dashed lines and faults in gray. The sample at the bottom of T39N is in a proxy location from a lower unit of channel 6, below the channel 4 deposits (see Fig. S1c available in the electronic supplement). The inset map and legend are same as in Figure 3 - click on image to open in a new tab - Wechsler at al. (2014)


By Jefferson Williams