Experts are warning Haiti to brace for more strong earthquakes over the next several decades.
A study by the Seismological Society of America says the magnitude 7 quake that wrecked much of Port-au-Prince two years ago was centered in the same place as a 6.6 quake in 1701.
That was followed by three more powerful earthquakes in 1751 and 1770, before 240 years of quiet that preceded the 2010 quake.
The experts say the 2010 earthquake may be the start of a new period of strong seismic activity. They say earthquakes are impossible to predict, but they call on Haitians to prepare by putting up stronger buildings.
The 2010 earthquake killed 250,000 people. Parts of Port-au-Prince are still in ruins.
Scientists say the Caribbean island of Hispanola, which is divided between Haiti and the Dominican Republic, was one of the earliest European colonies and has extensive seismology records dating back more than 500 years.