Event 1
In the Nacar Trench, excavated across the
East Anatolian Fault Zone,
Karabacak et al. (2012:310–315) identified a
sequence of surface-rupturing earthquakes recorded
within a narrow (~8–10 m) fault zone cutting both
ophiolitic basement and overlying sedimentary units.
Event 1, the oldest of the three most recent
earthquakes, is defined by a fault that cuts unit i
and terminates beneath unit j, indicating burial by
younger sedimentation. This event produced at least
~36 cm of vertical displacement within unit h,
demonstrating a significant surface-rupturing
episode. The upward termination of the rupture
below unit j marks a clear event horizon, showing
that deformation did not propagate into overlying
deposits and thus predates their accumulation.
The geometry of the fault planes associated with
Event 1, combined with measurable vertical offset,
indicates oblique slip with both strike-slip and
compressional components. This is consistent with
the broader structural setting of the fault zone,
where low-angle fault planes accommodate
transpressional strain.
Karabacak et al. (2012) did not supply a date range for Event 1.
