Morphotectonic map of the studied area Figure 2

Morphotectonic map of the studied area (coordinates are in Israeli TM grid). The map is based mainly on areal photos (dated 1945), interpretation, and complementary field work. Mapped are all lineaments, landslides, fluvial systems (with sites of channel displacement marked by open black circle) and alluvial fans located within the study area. Also shown are the sites of the paleoseismic trenches and the highest shore line of the Sea of Galilee, 170 m below sea level, achieved at 25 ka (Hazan et al., 2005).

JW: Ein Gev landslides are shaded purple

Katz et al (2009)


Katz et al (2009) found evidence for five to seven MW > 6 earthquakes from paleoseismic trenching and an analysis of paleo landslides around the Sea of Galilee. They dated five of these events to 45, 40, 35, 10, and 5 ka BP using the optically stimulated luminescence (OSL) method. They detected what may be a landslide evidence for an event younger than 5 ka BP which they suggested might have been caused by one of the mid 8th century CE earthquakes.

Map and Sections Chronology

The northern Ein Gev landslide exhibited a multi-phase sliding history where the youngest slide was dated to ca. 5 ka BP.
However, because the youngest slide had a fresh face with no colluviation , Katz et al (2009:289) suggested the possibility that an additional event might have occurred after 5 ka BP which might be related to one of the mid 8th century CE earthquakes.

Slope stability analysis
Northern Ein Gev lanslide

Slope stability analysis was performed on the northern Ein Gev landslide using the same methodology as was used for the Fishing Dock Landslide. Because the northern Ein Gev landslide exhibited a multi-phase sliding history, the sandstone of the Ein Gev formation (the unit that failed) was mechanically tested in two different states to extract an Initial Peak Shear Strength and a Residual Strength that would exist after the earliest failure. Test results are listed below:

Sample Mechanical State Cohesion
Friction Angle Factor of Safety
from Static Analysis
Critical Acceleration
Pristine Rock Peak Shear Strength 376 43° 4.5 0.95 g
Deformed Rock Residual Strength 0 38° 2.8 0.37 g
In order to assess the possibility that a severe rain storm could have caused the observed landslides, additional static analysis was performed at full water saturation with the water table at ground level. The slopes were found to be stable under these conditions suggesting that the landslides were seismically induced. Paleoseismic trenching also associated a seismic event at 5 ka BP with a landslide failure. Critical acceleration to induce sliding was estimated to 0.95 g when the sandstone of the Ein Gev formation was at Peak Shear Strength and 0.37 g at Residual Strength. This translates into local intensities of 9.2 and 7.7 respectively when using Wald et al (1999) for the conversion. Thus minimum PGA is estimated at 0.37 g and minimum Intensity is estimated at 7.7 for the presumably seismically induced landsliding events observed in the northern Ein Gev landslide.

Convert PGA to Intensity

Variable Input Units Notes
g Peak Horizontal Ground Acceleration
Variable Output - Site Effect not considered Units Notes
unitless Conversion from PGA to Intensity using Wald et al (1999)

Notes and Further Reading