Funding Agency: NSF, award # 0609759

Abstract An integrated, four-year geophysical and geological study of the Caribbean island of Jamaica, which straddles a major strike-slip fault restraining bend that has formed in response to partitioning of Caribbean-North America plate motion between the northern and southern boundaries of the Gonave sliver plate, is being carried out by a research team of scientists from the University of Wisconsin and the University of Texas. New geodetic, geomorphologic, paleoseismic, gravity, and seismic measurements are being combined to: (1) measure Caribbean plate motion near Jamaica to establish the full fault slip budget across the island and Gonave microplate motion relative to the Caribbean and North American plates; (2) establish the locations, slip senses, and long-term slip rates along major active Jamaican faults through a combination of geomorphologic, paleoseismologic, and targeted gravity studies; (3) construct and test forward and inverse models of fault slip rates, to distinguish between proposed models for how slip is transferred between the offset fault strands, and to improve earthquake hazard assessment in this densely populated and earthquake-prone country use constraints from all measurements; (4) combine results with GPS site velocities from Hispaniola to derive a model for Gonave microplate motion that is fully consistent with all the data.

This project should provide a better understanding of earthquake hazard in Jamaica, which has experienced two destructive earthquakes since 1600 and continues to be vulnerable to significant earthquake damage due to seismic energy focusing and liquefaction of unconsolidated alluvium in much of the heavily populated and economically important southern half of the country. The measurements should provide useful information about the earthquake cycle over range of spatial and temporal scales, including the millenial-scale seismic history and potential of the Plantain Garden fault near the capital city of Kingston to the year-to-year budget of interseismic elastic strain that is accumulating in all areas of the island. The research will be done in collaboration with the Jamaican Seismological Network, which is responsible for seismological network operation, seismic research, and earthquake hazard assessment and response.