Event CH4-E1 - Modeled Age 294-369 CE
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. (2014:14) found evidence for Event CH4-E1 in Trench T39
where it "breaks up through unit 425 and into unit
420 on several faults on both walls of T39".
Because the strata of unit 420 is relatively
thick, they were unable to locate an event
horizon. However, since there is "a thickening
of unit 420 in the
synclinal trough,"
they suggest that "the deformation is synchronous
with the deposition of unit 420", making unit 420
the "approximate event horizon.".
Wechsler et al. (2018:Table 3) date this event to
294–369 CE. Dating is based on a
Bayesian model of radiocarbon ages.
Only one radiocarbon sample was found and dated
in unit 420 and it was towards the top of unit
420. They suggest that Event CH4-E1 "occurred
early in the deposition of unit 420" which would
place the lone radiocarbon sample above the
faulting. However, they noted that if this sample
was taken in a faulted part of unit 420, "the
date of event CH4-E1 may be as much as a century
younger." They added that CH4-E1 cannot be
younger than the
basal deposit
of Channel CH3.
Wechsler et al. (2018:Table 3) estimated
that Events CH4-E2 and CH4-E1 combined to produce
2.7 m of offset.
Wechsler et al. (2018:219) suggest that it is
"likely both are moderate in size, each with
about 1.3 m of
horizontal slip."
