A detailed macroseismic study of the July 11, 1927 earthquake was carried out. A quantitative analysis of damage data provided a correlation for estimating (MM) intensities: I = 6.4 + 1.2 log (percentage of damaged houses). Using axis lengths and areas bounded by the ensuing isoseismal lines, the depth (16 to 28 km) of the event was estimated, and its probable epicenter located near Damiya bridge on the Jordan river. A comparison with the equivalent parameters, inferred from instrumental records, shows agreement between both sets of results and thus confirms the validity of the approach used in the macroseismic study.
The same procedure of studying macroseismic data was applied to an earlier (January 1, 1837) destructive earthquake. It was found that this latter event orginated in the upper crust, eastward of Safed, with a 6.25 to 6.5 magnitude.
The isoseismals of both these major earthquakes are elongated in a north-south direction, along the major structural trend in the area. The southern coastal plain of Israel seems generally less vulnerable to Jordan Rift Valley earthquakes than inland regions of similar epicentral distances, though local pockets of anomalous intensities are observed for both earthquakes.