Dr Barbara Carby Director of Hazard Management Cayman Islands

By Steven Knipp
steve@caymannetnews.com

Despite recent wire service reports, and some specialist websites, reporting an unstable volcano on Dominica, and undersea earth tremors off the coast of Grenada, Dr Barbara Carby, Director of Hazard Management Cayman Islands (HMCI) said that these are unlikely to pose any danger to Cayman.

According to British geologist Richard Teeuw, one side of the volcano called Morne aux Diables (Devil’s Peak) shows signs that it might collapse sometime in the future, sending million tons of rock into the sea, causing a tsunami.

“I can’t say what the precise risks are of an earthquake in the Eastern Caribbean causing problems which might affect Cayman,” Dr Carby said. “But I do believe that the risks would be slight. Distance tends to dissipate the power and height of a tsunami, and Cayman is quite far from Dominica.”

Although common hazards, both natural and manmade, such as hurricanes, floods and fires occupy much of the Cayman Islands Hazard Management team’s time, the eight-person department also keeps an eye open for less likely dangers, including earthquakes and tsunamis.

In fact, Washington DC-based National Science Foundation calls tsunamis the Caribbean’s “forgotten hazard.” The Foundation reports that “since 1498 there have been 27 verified true tsunamis and an additional nine as ‘very likely true tsunamis’. In the past 136 years there have been three destructive tsunamis in the Caribbean, the last one being in 1946.” There are reports that there were 100 fatalities caused by the tsunami that struck the Dominican Republic 63 years ago.

Despite the relatively low risk of earthquakes, Cayman has in fact already had some “tremors” in the past, said Dr Carby. Cayman has a network of four seismic stations -- one each in the Sister Islands and two in Grand Cayman, namely West Bay and Frank Sound.

This network has been in operation for almost three years, said Dr Carby, and they are in secure locations.

“They do not sit on a pole, but are placed directly on the ground and, because they have highly sensitive seismic-monitoring equipment, we don’t want to give their precise locations,” she said.

Dr Carby, who has a professional background in geology and has been involved in emergency preparation for more than 20 years, said that in future Cayman’s seismic stations will be linked to a Caribbean-wide earthquake monitoring and reporting network, which will allow the entire Caribbean region to have almost immediate access to information about earthquakes as they occur.

“The central location has not yet been decided, but it will need to be in a location where the information about an earthquake can be sent out immediately, because speed is obviously essential,” she said.

The disaster management official added that Cayman has in fact recorded several tremors in the past “because we lie very close to the boundaries of the Caribbean plate, where there is potential for undersea movements, undersea earthquakes and landslides”.

But Jamaica had a greater risk, said Dr Carby: “Cayman has several innate advantages compared to Jamaica; firstly because we are further from this undersea boundary than Jamaica; and also because the island of Jamaica actually has some very large faults which are considered ‘active’.”

She added: “Unlike Jamaica, Cayman has very little sediment. By that I mean the soil is extremely thin here. This means that even if there were an earthquake here, Cayman’s hard limestone bedrock tends to absorb the ‘energy’ of an earthquake. It is actually the severe shifting of the topsoil which causes all the destruction we come to think of when we see the effects of earthquakes. This is what caused so much damage to Mexico City in 1985.”