This is a Tsunami warning message taken from the Pacific Tsunami Warning Centre which cancelled a Caribbean sea watch yesterday:
AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS
ORIGIN TIME – 2153Z 12 JAN 2010
COORDINATES – 18.5 NORTH 72.5 WEST
LOCATION – HAITI REGION
MAGNITUDE – 7.1
A TSUNAMI MEASURING 12 CM CREST-TO-TROUGH WAS RECORDED AT SANTO
DOMINGO IN THE DOMINICAN REPUBLIC AND A TSUNAMI LESS THAN 1 CM
CREST-TO-TROUGH WAS RECORDED ON A DEEP OCEAN GAUGE IN THE
Some more technical information was made available by the US Geological survey:
At the longitude of the January 12 earthquake, motion between the Caribbean and North American plates is partitioned between two major east-west trending, strike-slip fault systems — the Septentrional fault system in northern Haiti and the Enriquillo-Plaintain Garden fault system in southern Haiti.
The location and focal mechanism of the earthquake are consistent with the event having occurred as left-lateral strike slip faulting on the Enriquillo-Plaintain Garden fault system.
The Haitian Ambassador to the United States has made a plea for help and President Obama has expressed his sympathies with the people of Port-au-Prince, who were worst affected.