The mid-8th century CE surface faulting along the Dead Sea Fault at
Tiberias (Sea of Galilee, Israel)
Abstract
The Dead Sea Fault (DSF) is a plate-boundary where large earthquakes are
expected and largely overdue due to the lack of such events in the
instrumental era. Sequences of earthquakes along the DSF are documented
by historical evidence, one of the most devastating occurred in the
mid-8th century CE. Here we describe site-specific archaeoseismological
observations at the ancient Tiberias city, on the western shore of the
Sea of Galilee. We map Roman and Byzantine relics faulted in the mid-8th
century CE by a pure normal fault. We use geophysical, geomorphological
and structural analyses integrated with published data, to assess the
seismic hazard of the Jordan Valley Western Boundary Fault (JVWB). We
propose that the normal JVWB can rupture the surface along its
~45 km trace running from Tiberias toward the S crossing
Bet Shean, Tel Rehov and Tel Teomim. The JVWB, parallel to the main
strike-slip Jordan Valley Fault segment, might be regarded as a major
earthquake source in this region. We test the hypotheses of both single
fault and multi-faults rupture scenarios, which result in an expected
range of Mw from 6.9 (single rupture of the JVWB) to 7.6 (multiple
rupture of the JVWB and Jordan Valley Fault). Our results suggest that
seismic source characterization in the Sea of Galilee region must
include normal faults capable of surface rupturing, despite the absence
of such events in the instrumental catalogue.