Earthquake Hazard in the Caribbean Eric Calais UNDP and Purdue University

Whose Fault?

Hispaniola is “squeezed” at a constant, inexorable, speed of 2 cm per year This motion puts the whole islandunder pressure – earthquakes release it As long as plates will move, there will be earthquakes Lesson #1: since plate motion is inexorable, seismic hazard is inexorable

Population at Risk for Natural Hazards 11.3 M 2.7 M 0.3 M 16.5 M 3.9 M 2.0 M 1.1 M 25 M 42 M 3.0 M 4.0 M 5.4 M 6.8 M 6.6 M Total = 130 M Source: CIA Factbook

Seismic Research Unit The University of the West Indies St. Augustine Trinidad Tel Fax Caribbean earthquakes The instrumental Period This slide shows earthquakes since Note that although there is far greater detail, the general pattern is the same

Frankel, A.et al., Documentation for Initial Seismic Hazard Maps for Haiti, USGS Open- File Report Includes GPS and some fault information. Range of above map 2010 OAS Caribbean Disaster Management Project, map similar to Global Seismic Hazard Assessment Program (GSHAP) Based on recent seismicity = 33 % g = 3 % g Ground shaking

Jamaica Spectral Hazard Maps

Compilation R. Bilham (U. Colorado), figure A. Freed (Purdue)