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TSUNAMI RESPONSE TIME IS SHORT: GET READY!!! Print E-mail
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Written by By Rudolph Williams   
Thursday, 03 May 2018 00:00

On January 9 this year around 7:50 p.m. we were all alerted by sirens and fire alarms.  We were not sure what the sirens and alarms were all about, was it a fire warning?  It could not be hurricane. What was all this noise about?  Then we heard the police bullhorns alerting citizens of a possible tsunami threat.  In the aftermath, many were and continue to declare that a tsunami threat is a new event for Belize.

Whilst tsunami threats are not as common as the threats during our hurricane season, it is definitely not new.  The last time a similar tsunami threat was issued on May 28, 2009 around 2:45 a.m.  The 2018 and the 2009 tsunami alerts were the consequence of magnitude 7.6 and 7.3 earthquakes respectively that occurred along the Swan Islands Transform Fault as the result of strike slip faulting in the shallow crust near the boundary between the North America and Caribbean plates in the Western Caribbean Sea.  Over the past 100 years, 9 earthquakes of magnitude 6 or greater have occurred with 400 kilometers of the January 10, 2018 event.

Today the January 2018 tsunami alert event is the most discussed, however history documented at least six tsunami events occurring in the northwestern Caribbean Sea.

The earliest documented, is the November 24, 1539, tsunami event, just east of Punta Negra was the result of 7.5 earthquake.  There are conflicting reports on its location.  This event likely originated in the northern part of Honduras rather than Port of Honduras, Belize.  The description of the location references “Higueras” which is an early name for present-day Honduras.  A violent seaquake was felt 160 kilometers off the coast of Honduras and there were massive landslides and the loss of one large house.  On August 04, 1855 another tsunami was reported near Trujillo in Honduras.  A heavy 15-second shock occurred at Trujillo triggered a seaquake which caused heavy damage. A total of nine shocks were counted.  The shocks were accompanied with three days of heavy rains.  Again it is doubtful that this event was triggered by an earthquake and is possibly associated with a hurricane.

On August 4, 1856, an earthquake of magnitude 7 or 8 occurring between Honduras and Jamaica in the Cayman Trench, jolted the coast of Honduras destroyed the town of San Jose caused major damage in the Port of Omoa, cracked the walls of an old Spanish fortress and on the ground in 12 miles radius between the deltas of the rivers Tinto and Ulua. The sea withdrew and increased on its return.  The runups caused standing waves (seiche) in the Sieve lagoon, rivers to change direction, and destroyed several towns.

Then there was 7.5 earthquake that rocked Guatemala City on February 4, 1976, and generated a small tsunami that was recorded at the Puerto Cortez tidal station in Honduras. The maximum crest to trough amplitude recorded at this station was 24 centimeters. The arrival of the first wave occurred at approximately only 10 minutes after the earthquake.

Now back to the 2009 event, with a maximum water level of 4 metres with runups occurring 240 kilometres from the epicenter in Quetzalito and the Rio Motagua in Guatemala.  The 2009 earthquake was much closer to land than the 2018 event and it resulted in 7 fatalities, 40 injuries and 130 buildings being damaged or destroyed in Honduras. The Tsunami Warning Center forecasted that the tsunami should be on Belizean coast 20 minutes after the quake occurred.  Immediately after the event we reported that there were no runups in Belize, however, there were reports of homes sinking in the Monkey River Village, which is indicative of runups in Belize.

The January 2018, our most recent event, has revived the need to prepare emergency response for tsunamis in Belize.  This event was around 480 kilometres from Belize with a maximum water level of 40 centimeters at Roataan.  Belize experienced runups of 2 and 1 centimeters at Carrie Bow Caye and Port of Belize, 1 hour and 5 minutes and 1 hour and 38 minutes respectively after the event. While Cayman experienced 26 centimeters and Puerto Morelos 8 centimeters.  Thankfully damage was less than 1 million dollars and there were no deaths.

Tsunamis originating near Puerto Rico can affect Belize within 4 hours, Jamaica within 2 hours, Bay Islands less than 1 hour and we see that.  We have been fortunate, but as the creole proverb states, “evry fat cow have ih Sunday”.  We need to get ready, the response times are very short.  A good early warning system, should have a response time under 1 hour, systems with frequency Specific Sirens should be installed in all the vulnerable communities regardless of size, and refuge centers.  As with hurricane preparedness continuous tsunami educational programs should be implemented.