Jamaica - SEG

Location: Jamaica
Status: Complete
Project Partners: The University of Texas at Austin, Earlham College, Engineering Geology- University of Technology, Jamaica, University of West Indies- Mona, Office of Disaster Preparedness and Emergency Management (OPDPM), Petroleum Corporation of Jamaica and Jamaican Navy and Coast Guard.
Focus Area: Earthquake Preparedness

Overview
The goal of this study was to quantify slope stability along the Kingston harbour waterfront, and in particular, along [the] southern edge of the Harbour near Port Royal … as this area has been prone to frequent, sometimes devastating slope failure and liquefaction events associated with earthquakes.

Approach
This study combines sediment strength analysis with earthquake probabilities to assess (1) the magnitude of past events that triggered slope failure in the Harbour and (2) the likelihood and location of future slope-failure events in and around the southern edge of Kingston Harbour.

Impact

The Monte Carlo solution for the minimum Factor of Safety (FS) value of ~2.04 indicated the region is very stable under normal gravitational conditions if sediments maintained their shear strength.

The analysis implied that “an earthquake movement of a magnitude as low as Mw 5, if it occurs within three kilometres of the site, would trigger failure.”

Liquefaction FS analysis showed “relatively minor ground shaking can cause potentially significant liquefaction at this site.”

Probability analysis indicated a return period of ~18-29 years for Mw 5 events and ~286 years for Mw 6 events around the 25 km zone near Port Royal.

The study emphasised that “the Kingston/Port Royal area is due for an earthquake in the Mg 5 range in the near future (based on averages).

The findings underscored the urgency of slope-failure and liquefaction risk around the Palisadoes/Port Royal–Kingston region, and provided a quantitative foundation for hazard mitigation and planning efforts.