2010 Haiti quake possible start of new cycle of seismic activity

The island of Hispaniola, which is home to the two countries of Haiti and Dominican Republic, has a long seismic history, recorded by explorers, pirates and settlers from Spain, France, England and Holland. There are ample accounts of the physical condition of the island over the last 500 years that U.S. Geological Survey researchers used to evaluate the intensity of past earthquakes and estimate their location and magnitudes.

This article documents the seismic activity along the Enriquillo fault system, which reflects a period of significant earthquakes with intense aftershocks, followed by a long 240-year period of relative seismic quiescence. The island's last intense period of seismic activity was from 1700 to 1770. Author William Bakun and his colleagues point to the similar seismic pattern in the San Francisco Bay Area, where the seismic cycle includes a period of significant earthquake activity followed by a period of relative quiescence.

While the January 2010 earthquake that struck Haiti was only magnitude 7.0, it caused great damage and loss of life due to poor planning and inadequate building practices. Bakun and his colleagues suggest planning for strong earthquakes based on the pattern of earthquakes that have occurred since 1500.