This map is a NASA radar image taken by the Shuttle Space Endeavor in 2000. The Image is color coded for elevation and shows how Port-au-Prince is situated on the same depression as the salt water lakes. It is along this depression that earthquake activity threatens to separate the southern peninsula from the rest of the island. The impression of the southern fault (Enriquillo- Plaintain Garden Fault) line on the surface can be seen running through the southern peninsula.
Just like other Caribbean islands, Haiti periodically experiences earthquakes caused by the Caribbean tectonic plate shifting alongside the North American plate. The plate movements have led to the formation of two very active fault zones similar to the San Andreas Fault zone in California. The northern fault zone passes through the city of Cape Haitian and continues west beyond the island of Tortuga. It is called the Septentrional-Orient Fault. The southern fault zone, called the Enriquillo-Plaintain Garden fault, passes through the city of Port-au-Prince, and continues west through the southern peninsula. There is another but less active fault that passes through the central plain of Haiti called the Gonaive Fault zone. Movement of the earth along faults like these causes periodic earthquakes in Haiti.Below are some of the most devastating earthquakes that Haiti has experienced.
Earthquakes along the northern fault zone
The earliest recorded earthquake on the island occurred in 1564 and affected the regions in the vicinity of the northern fault zone. This earthquake destroyed the colonial cities of Santiago and Vega which are separated by 30 kilometers.Another earthquake destroyed the principal church of Santiago in 1783. Twenty five minor earthquakes affected Fort Liberte, Petite Anse and Cape Haitian between 1783 and 1786. One of the worst earthquakes to strike the region occurred at 5:30pm on Saturday May 7, 1842 and lasted for less than one minute. The quake was felt from Samana, on the eastern part of the island to Mole St Nicholas on the northwestern tip. Its worst effect was felt in Cape Haitian where half of the inhabitants died. Santiago, Port-de-Paix, Fort Liberte, Mole St Nicholas were all destroyed.All homes in Port-de-Paix were destroyed.The aqueducts that brought water to Mole St Nicholas were also destroyed. The majestic Sans Souci Palace was destroyed. The Citadelle withstood the quake in testimony to its great architectural design. Immediately after the quake, the air filled with dust. Roads cracked or were destroyed. New springs appeared.Five thousand of the nearly 10,000 people living in Cape Haitian died, including public officials and army personnel.Some government officials who did survive abandoned their post. Aftershocks continued until June 28th, 1842.This devastating earthquake took place while the United States enforced an embargo against Haiti and France enforced the payment of an indemnity. Apparently, Haiti never quite recovered from the 1842 earthquake which was named levenman – the event.For a while, people of northern Haiti referred to events as either occurring before or after levenman. The political aftershocks were even more profound. The government of then President Boyer became unstable as Piquet rebels threatened to take over the south and eastern rebels succeeded in declaring the independence of the Dominican Republic in 1844.
On September 23, 1887 at 6:55am there was another earthquake that mostly affected the north of Haiti. Nearly all the homes in Moles St Nicholas were destroyed. The tremor was felt all across the country. On September 29th 1897 at 6:32 am, the northern region suffered yet another earthquake.
Earthquakes along the central and southern fault zone
The first recorded earthquake originating from the central plain fault zone occurred in 1673. Another occurred in 1684. In 1691, the region was struck by another earthquake which destroyed the colonial city of Azua.A powerful earthquakestruck the central region in November 9th, 1701. Homes as far as Leogane that were built of masonry were destroyed and the road leading from Leogane to Petit Goave sank into the sea.Other earthquakes occurred in 1713, 1734, and 1751. This latter earthquake occurred on October 18, 1751 at 2pm. It was felt in Croix des Bouquets and in Port-au-Prince. The southern fault zone is so active that seismic activity in this rift valley threatens to separate the southern peninsula and make it a completely separate island. Two salt water lakes sit on top of this fault zone – Lake Saumatre/Azuai and Lake Enriquillo.
In October of 1751, Port-au-Prince was hit by a severe earthquake.Three quarters of the homes in Port au Prince were built of masonry and most were destroyed.The government devised plans to rebuild the city in wood but this was never done. On June 3rd, 1770, another earthquake hit the region and so badly damaged Port-au-Prince that it was called the Port-au-Prince Earthquake.Historians reported that the earth opened in 1000 places.All government buildings were destroyed.All homes in Petit Goave and Miragoane were destroyed.On April8th, 1860,Port-au-Prince was affected by yet another earthquake. The population took shelter in the street, as twenty to thirty additional aftershocks were felt between April 8th and April 11th. Although Port-au-Prince has experienced minor and major earthquakes from time to time, the city repeatedly failed to apply the lessons that it had learned from its past.In 1946, an earthquake of magnitude 8.0 struck the Dominican Republic and was felt in Port-au-Prince.
In recent years, Port-au-Prince has expanded to become a city of about 2 to 3 million people with a large number living in homes built of masonry. Many of these homes again toppled during the recent earthquake of January 12, 2010, claiming countless lives. The geology of the island makes earthquakes in Haiti inevitable. As we move forward, we must heed the lessons of the past.We can minimize the damage and loss of lives caused by these earthquakes with better building codes and with better disaster relief plans.
References: 1. Scherer, J. (1912). "Great Earthquakes in the Island of Haiti". Bulletin of the Seismological Society of America 2: 174–179 2. M. Pubellier, J.M. Vila, D. Boison. North Caribbean neotectonic events: The Trans-Haitian fault system. Tertiary record of an oblique transcurrent shear zone uplifted in Hispaniola. Tectonophysics 194 (1991) 217-236