TSUNAMIS TRIGGERED BY THE 12 JANUARY 2010 HAITI EARTHQUAKE

On 12 January 2010 a magnitude M_w 7.0 earthquake occurred 25 km west-southwest of Haiti’s capital Port-au-Prince causing an estimated 316,000 fatalities, thereby exceeding any previous loss of life from a similar size earthquake. Triggered tsunami waves caused at least 3 fatalities at Petit Paradis. Unfortunately, the people of Haiti had neither ancestral knowledge nor educational awareness of tsunami hazards despite the 1946 Dominican Republic tsunami at Hispaniola’s northeast coast. In sharp contrast Sri Lankan UN-soldiers on duty at Jacmel self-evacuated given the memory of the 2004 Indian Ocean tsunami. The 31 January to 7 February 2010 ITST covered the greater Bay of Port-au-Prince and more than 100 km of Hispaniola’s southern coastline between Pedernales, Dominican Republic and Jacmel, Haiti. The collected survey data include 21 tsunami heights along with observations of coastal land level change. Maximum tsunami heights of 3 m were measured both at Petit Paradis inside the Bay of Grand Goâve located 45 km west-southwest of Port-au-Prince and at Jacmel on Haiti’s south coast. Jacmel, which is near the center of the south coast, represents an unfortunate example of a village and harbor that was located for protection from storm waves but is vulnerable to tsunami waves. The runup roughly doubled from the bay entrance to the head of the bay. Inundation and damage were limited to less than 100 m inland at both Jacmel and Petit Paradis. Differences in wave period were documented between the tsunami waves at Petit Paradis and Jacmel. The tsunami arrival times recorded by the DART buoy and the Santo Domingo tide gauge in combination with tsunami modeling indicate that the tsunami on Hispaniola’s south shore was triggered co-seismically. The tsunami flooding inside the Gulf of Gonâve is attributed to a coastal submarine landslide at Petit-Paradis, while the exact source of the tsunami on the south shore of Hispaniola remains to be determined. Field observations, video recordings, satellite imagery and numerical modeling are presented. The team interviewed numerous eyewitnesses and educated residents about the tsunami hazard. Observations will be compared to recent tsunami events around the world. Community-based education and awareness programs are essential to save lives in locales at risk from locally generated tsunamis.