Speaker: Hermann M. Fritz
“This is a seminar in two parts reporting on two recent tsunami events in the Americas:
On 12 January 2010 a magnitude Mw 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. In addition tsunami waves triggered by the earthquake caused at least 3 fatalities at Petit Paradis due to a complete lack of tsunami awareness. The international tsunami survey team (ITST) was deployed within weeks of the event and covered the greater Bay of Port-au-Prince and more than 100 km of Hispaniola’s southern coastline. The collected survey data include more than 21 tsunami heights along with observations of coastal land level change. Maximum tsunami heights of 3 m have been measured for two independently triggered tsunamis. The tsunami flooding inside the Gulf of Gonâve is attributed to a coastal submarine landslide at Petit-Paradis. Observations and modeling results identified the source of the regional tsunami on the south shore of Hispaniola, but the exact source remains to be determined.
On February 27, 2010, a magnitude Mw = 8.8 earthquake occurred off the coast of Chile’s Maule region causing substantial damage and loss of life. Ancestral tsunami knowledge from the 1960 event combined with education and evacuation exercises prompted most coastal residents to spontaneously evacuate after the earthquake. Many of the tsunami victims were tourists in coastal campgrounds. The international tsunami survey team (ITST) was deployed within days of the event and surveyed 800 km of coastline from Quintero to Mehuín and the Pacific Islands of Santa María, Mocha, Juan Fernández Archipelago, and Rapa Nui (Easter). The collected survey data include more than 400 tsunami flow depth, runup and coastal uplift measurements. The tsunami peaked with a localized runup of 29 m on a coastal bluff at Constitución. The observed runup distributions exhibit significant variations on local and regional scales. Observations and modeling results from the 2010 and 1960 Chile tsunamis are compared.”