Insurers Must Calculate Risks of Tsunamis That Typically Follow Earthquakes

The Jan. 12, 2010 Haiti earthquake demonstrated the threat of massive earthquake damage in a region better known for exposure to tropical storms. However, it also demonstrated, as with many seismically active coastal zones, the Caribbean's vulnerability to tsunamis.

The Haiti earthquake and its aftershocks were caused by strike/slip faults which are characterized by predominately lateral motion relatively near to the earth's surface, according to Don Blakeman, a seismologist with the U.S. Geological Survey. Significant tsunamis involve greater vertical motion of the sort created by earthquakes emerging deep below the surface. Atlantic tsunamis are rare, according to Blakeman, but the potential for such events exists at the subduction zone where the Caribbean plate tectonic plate is moving over the Atlantic sea bed.

Don Windeler, director of model management, Risk Management Solutions (RMS; Newark, Calif.) says that, "The lesser Antilles, to the east [of Haiti] can experience significant subduction-related earthquakes, which can be much larger than the Haiti event but are generally deeper and offshore."

According to a NOAA (National Oceanic and Atmospheric Administration) presentation entitled "The Forgotten Danger, the Indian Ocean "Christmas Tsunami" of 2004 should be a wake-up call for the Caribbean. The report says, "The Caribbean's lesson from the catastrophic Indian Ocean tsunami: despite tsunami infrequency, large coastal populations and explosive tourism results in the potential for enormous loss of life."

The warm water coast of the Caribbean — like the Indian Ocean —'creates the opportunity for tremendous loss of life, owing to the heavy habitation and tourist activity. Caribbean beaches feature more flat, low-lying topography, which maximizes beach attendance while decreasing the opportunity to escape, according to the NOAA report. Geophysical data collected by the NOAA suggests that the Caribbean Basin has had 8 percent of the world's tsunami events and the Indian Ocean has had 7 percent.

Within the last 165 years, 3,503 deaths have been attributed to tsunamis across the Caribbean, from Haiti to Venezuela, according to the NOAA. Though the Caribbean has only one fifth the area of the northeastern Pacific area, it has suffered six times the number of deaths, the report says.

Significant tsunami events affecting U.S. territory include a September 2009 event that killed 34 people in American Samoa, the Insurance Information Institute (iii) reports. In 1964, a tsunami killed 11 people in Crescent City, Calif., just south of the Oregon border. The event was caused by an earthquake in Alaska.

Anthony O'Donnell has covered technology in the insurance industry since 2000, when he joined the editorial staff of Insurance & Technology. As an editor and reporter for I&T and the InformationWeek Financial Services of TechWeb he has written on all areas of information ... View Full Bio