Was there any previous earthquakes in haiti before the 2010 one?

Answer 1

Simple description of the cause of the Haitian earthquake. For a more in depth technical description, see below:

The surface of earth including the crust and the upper mantle which make up the hard rocky part we stand on is broken up into different pieces. These are called tectonic plates and they float on the much thicker denser layer below called the asthenosphere.

The asthenosphere acts like a very thick liquid (imagine very thick treacle) that flows very slowly. As the tectonic plates are floating on the asthenosphere, they move as well.

In some places they crash into each other and in others they slide past each other. Haiti is very close to a place where two plates are moving past each other. The edges of the two plates are rough and jagged, so they get stuck or locked together. However the asthenosphere is still moving below them and so they still want to move as well. This makes pressure build up and when this gets to high, the two plates slip suddenly past each other and all the built up energy is released at one time. This makes the earthquake waves that caused the Haitian earthquake.

Technical Description of the Haitian EarthquakeRegional tectonic setting of Haiti and historical seismicity:

The Caribbean Sea is an active tectonic zone, where the smaller Caribbean Plate is sandwiched between the larger North American and South American plates. The northern edge of the plate extends from Guatemala in the west, south of Cuba, and north of Hispaniola and Puerto Rico. The Caribbean side shifts eastward at a rate of approximately 20mm/year relative to the North American plate into a subduction zone that has created the volcanoes of the Lesser Antilles. This has produced the disastrous 1902 eruptions on Saint Vincent and Martinique, and the current one on Montserrat.

Earthquakes have occurred historically in Haiti. Widespread damage occurred in 1751, 1770, and 1842, and an 8.0 magnitude quake struck to the east, in the Dominican Republic, in 1946.

After studies in 2006 and 2008, geologists estimated that a major tectonic shift was expected, as the east-shifting northern plate boundary had been locked and not relieved for more than 40 years.

Detailed explanation of the cause of the Haitian earthquake:

More specifically, on a subregional tectonic scale, Haiti is situated on the eastern end of of a smaller plate that separates the Caribbean and the North American plates known as the Gonave micro-plate. This micro-plate and hence Haiti is bounded to the north by the Oriente and Septentrional Fracture Zones and to the south by the Enriquillo-Plantain Garden fault which are both transform faults (very similar to the San Andreas Fault in the USA).

The Enriquillo-Plantain Garden fault has been locked for approximately 250 years. As such, stresses have accumulated in the earth's crust over this time, causing energy to be stored in the form of elastic strain (like that in a compressed spring). Ultimately this stress has exceeded the shear strength of the crust in the fault zone causing a sudden brittle failure or rupture. This in turn causes movement and a sudden release of the stored elastic strain energy in the form of seismic waves (as well as heat and sound).

The rupture of the fault zone was approximately 65 km (40 miles) in length with an average slip of 1.8 m (5.9 ft). Analysis of seismometer data showed that the seismic waves produced by the movement on the fault had amplitudes of up to 4 m (13 ft).

Please see the related question for more information about the Haitian earthquake.

Answer 2

The following are the worst-affected areas after the earthquake:

• Leogane
• Port-au-Prince
• Petit Gauve
• Grand Gauve
• Jacmel
• Miragoane
• St. Marc
• Le Cayes

You can also check out this link for more information...

http://www.guardian.co.uk/world/interactive/2010/jan/13/haiti-earthquake-disaster-map

_________

The quake's epicenter was located 16 miles west of the capital, Port-au-Prince with a focus approximately 6.1 miles underground. Because the quake was centered in land and not in the surrounding ocean, the tremors were felt strongly throughout Haiti and the surrounding countries. (The quake was even felt in Tampa, FL, and Caracas, Venezuela.) Within Haiti, cities most affected were Port-au-Prince, Jacmel, Leogane, Carrefour, Petit-Goave, Gressier and Cabaret. Numerous buildings were destroyed, especially in Port-au-Prince, where the National Palace, Port-au-Prince Cathedral, Parliament Building, Port-au-Prince seaport and numerous hospitals were damaged. The damage was especially devastating because Haiti already ranks lowest in the Western Hemisphere on the Human Development Index (see http://hdrstats.undp.org/en/countries/country_fact_sheets/cty_fs_HTI.html), and has few resources to spare.

The quake occurred because of Haiti's location on the intersection of the Caribbean tectonic plate and the North American Plate. The Enriquillo-Plantain Garden fault runs through southern Haiti and has had unreleased tension building in it for 250 years. A good resource is http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/us2010rja6/#summary. It also includes maps (such as this one: http://earthquake.usgs.gov/earthquakes/shakemap/global/shake/2010rja6/) that show the impact across the country.

Answer 3

Earthquakes have occurred historically in Haiti.

Widespread damage occurred in 1751 when a major earthquake destroyed Port Au Prince. This was repeated in 1770 when a major seismic event again destroyed Port Au Prince and in 1860 a major earthquake to the east of Haiti generated a Tsunami

More recently, a magnitude 8 earthquake struck to the east of Haiti, in the Dominican Republic, in 1946.

Answer 4

The duration of the initial earthquake was 30 - 40 seconds. There were several smaller aftershocks. (See links below)

Answer 5

No. Haiti has never experienced an earthquake like this in its history.

Answer 6

The severity of the Haitian earthquake was ranked as Extreme (Level 10 or X) on the Modified Mercalli (MM) scale.

Please see the related links and questions.

Answer 7

Earthquakes significantly affected Haiti in 1751, 1770 and 1842.