UPDATE: The tsunami warning has been cancelled for Costa Rica, Panama, and Nicaragua after a 7.6 magnitude earthquake shook off the coast of Costa Rica on Wednesday.
According to an evaluation by the Pacific Tsunami Warning Center:
ALTHOUGH SEA LEVEL READINGS DO NOT INDICATE THAT A TSUNAMI WAS GENERATED… THERE MAY HAVE BEEN DESTRUCTIVE WAVES ALONG COASTS NEAR THE EARTHQUAKE EPICENTER.
FOR THOSE AREAS – WHEN NO MAJOR WAVES ARE OBSERVED FOR TWO HOURS AFTER THE ESTIMATED TIME OF ARRIVAL OR DAMAGING WAVES HAVE NOT OCCURRED FOR AT LEAST TWO HOURS THEN LOCAL AUTHORITIES CAN ASSUME THE THREAT IS PASSED. DANGER TO BOATS AND COASTAL STRUCTURES CAN CONTINUE FOR SEVERAL HOURS DUE TO RAPID CURRENTS. AS LOCAL CONDITIONS CAN CAUSE A WIDE VARIATION IN TSUNAMI WAVE ACTION THE ALL CLEAR DETERMINATION MUST BE MADE BY LOCAL AUTHORITIES.
NO TSUNAMI THREAT EXISTS FOR OTHER COASTAL AREAS IN THE PACIFIC ALTHOUGH SOME OTHER AREAS MAY EXPERIENCE SMALL SEA LEVEL CHANGES.
THE TSUNAMI WARNING IS NOW CANCELLED FOR ALL AREAS COVERED BY THIS CENTER.
ORIGINAL STORY – posted 6:20 a.m. on Sept. 5, 2012: A tsunami warning is in effect for Costa Rica, Panama, and Nicaragua after a 7.6 earthquake struck off the coast of Costa Rica on the morning of September 5th, 2012.
The Pacific Tsunami Warning Center says it is not known of a tsunami was generated and that the warning is based on earthquake information. The PTWC says:
AN EARTHQUAKE OF THIS SIZE HAS THE POTENTIAL TO GENERATE A DESTRUCTIVE TSUNAMI THAT CAN STRIKE COASTLINES IN THE REGION NEAR THE EPICENTER WITHIN MINUTES TO HOURS. AUTHORITIES IN THE REGIONSHOULD TAKE APPROPRIATE ACTION IN RESPONSE TO THIS POSSIBILITY. THIS CENTER WILL MONITOR SEA LEVEL GAUGES NEAREST THE REGION AND REPORT IF ANY TSUNAMI WAVE ACTIVITY IS OBSERVED. THE WARNING WILL NOT EXPAND TO OTHER AREAS OF THE PACIFIC UNLESS ADDITIONAL DATA ARE RECEIVED TO WARRANT SUCH AN EXPANSION.
The tsunami warning does not include Hawaii, but an evaluation for a Pacific-wide tsunami is underway and “there is a possibility that Hawaii could be elevated to a watch or warning status”, the PTWC says.
If there a tsunami were to arrive in Hawaii, it would be at around 2:45 p.m.