What if Guyana...? Our vulnerability to water and wind

What if Guyana…? Our vulnerability to water and wind

Aug 02, 2015 Countryman, Features / Columnists

By Dennis Nichols

My last ‘Countryman’ briefly and somewhat lightly addressed the Venezuelan threat to Guyana’s sovereignty. Now I want to look at another possible menace, this time to the livelihood of our country’s coastal population, and to our infrastructure and industries. This threat concern is prompted partly by recently reported rumblings of an underwater volcano in the Caribbean Sea, the possibility of a resultant tsunami, and the stark reality that our narrow coastal belt generally lies below sea level.
But it isn’t only a tsunami stemming from an eruption of the submarine volcano ‘Kick ‘Em Jenny’ that can wreak havoc on our coastline. Guyana may not be entirely safe from the kind of severe tropical storms and hurricanes which have caused widespread destruction to many of our Caribbean neighbours.
We Guyanese like to think of ourselves as being just outside the Atlantic hurricane zone stretching from off the west coast of Africa to the Caribbean Sea and the Gulf of Mexico, but global climate patterns are changing, and according to the U.S. Environmental Protection Agency, (EPA) such storms will become ‘more frequent or more intense with human-induced climate change.’ Maybe also more widely distributed.

Storm surge from Hurricane Sandy at Ocean Grove Pier – New Jersey, USA, October 29, 2012 – Photograph by Bob Bowné (news.yahoo.com)

In 2004, for example, our neighbour Brazil experienced its first ‘real’ hurricane off the Catarina shore in its south-east region, much to the astonishment of local forecasters who refused to accept that it was indeed one. Venezuela and Colombia have also experienced hurricanes. And to strengthen the point about out-of-zone storms, Britain, which is rarely associated with these events, has been hit increasingly since the turn of the century with major tropical-like storms bringing hurricane-force winds – in 2000, 2006, 2011 and 2014.
But back to that underwater pressure-cooker with the strange name; (incidentally Jenny may have a brother, a crater discovered nearby in 2003 not surprisingly named Kick ‘Em Jack) Should Jenny erupt forcefully, it could trigger a tsunami that may affect eastern Atlantic shorelines from the United States to the north-eastern coast of South America including, of course, the Caribbean islands and Guyana.
Is this far-fetched speculation? Some experts do think so, saying it’s unlikely that it could trigger a tsunami since its dome lies in ‘extremely deep water’ of about 200 metres below the surface of the sea.
This confuses me, because the average depth of the Atlantic is about two-and-a-half miles, and in the Puerto Rico trench it plunges to some 28,000 feet (more than five miles). Two hundred metres seems pretty shallow, hopefully unlike the experts whose statistics we have to trust. And although the Orange Alert issued by the University of the West Indies Seismic Research Centre (SRC) remains in effect, the SRC said it is recording reduced activity levels. But scientists and weather forecasters don’t always get it right.
Coastal flooding in Guyana over the past year has occurred with limited warning of its intensity and duration by the local meteorological office. And on at least two occasions when heavy rains were predicted to continue after the main deluge, it didn’t happen.
So how accurate are these forecasts? The weather worldwide is becoming more chaotic and unpredictable. Should we in Guyana then worry about hurricanes and tsunamis? Maybe!
Apart from a volcanic eruption, a tsunami may result from an earthquake caused by the movement of continental and oceanic tectonic plates. It may also be caused by an underwater landslide or by a large meteorite striking the ocean.
In each case, a huge amount of water would be displaced in the form of giant waves which, in the case of an earthquake, may travel thousands of miles at speeds up to 500 mph. On reaching land they may travel as far as 10 miles inland. God forbid, but think what that would mean for Guyana’s coastal dwellers once our seawall is breached. (On a positive note, Guyana’s land mass is undergirded by a shield of ancient rock which lends stability to it and other nearby countries, thus reducing the chance of a major quake)
It however doesn’t extend to the ocean, which means that underwater activity in the Atlantic is still a problem for us, and there are several other unstable submarine areas in the north Atlantic from which a monster wave can reach us in a few hours.
Now what about hurricanes? Within the past month two so-called freak storms hit Guyana without warning. The first, on June 28th, swirled in from the Atlantic in mid-afternoon. It ripped zinc sheets from roofs, felled power lines, billboards and fences, and uprooted trees. The second, exactly one week later, tore through the upper Corentyne area causing similar damage estimated at millions of dollars. Neighbouring areas in Suriname were also affected.
Although I can find no reports as to the wind speed in these squalls, I can give my own estimate based on the two hurricanes I experienced in The Bahamas; I would guess about 40 to 50 mph, below that of a Category One hurricane, the least destructive of five ranks on the Saffir-Simpson Scale with winds between 74 and 95 mph.
A Cat 5 storm has sustained winds in excess of 157 mph, and a cyclone off Australia in 1996 had a recorded gust of 253 mph. That would be absolute devastation in a country like ours.
But even a storm of medium intensity can be catastrophic for Guyana’s coastal dwellers, because of the phenomenon known as storm surge which usually accompanies a hurricane making landfall. I saw a mild one in The Bahamas, and it was frightening. The build-up of water in a surge, is sudden and disorienting, and can cause severe flooding in a very short time.
It is truly scary to see water at sea level rise 10 or more feet in a short time, monstrously driven by 90 mph winds, and quickly inundate large swaths of coastland. Is our four-foot high seawall adequate protection from such a powerful force, especially in conjunction with a high tide? I think we know the answer; at least our Civil Defence Commission should.
I am not sure how educated we are as a nation about the perils of a natural disaster such as a hurricane or tsunami – what to expect, and what arrangements/contingencies are in place for evacuation, shelter, food and medical aid should it come to the worst. A mass exodus of tens of thousands of people from the coast to higher ground and inland locations can be a nightmare given the limited access by road and river to such areas, and the logistics involved. Look at what happens with relatively minor floods!
There are of course numerous other factors to take into consideration before or during such an eventuality, e.g. the ability of buildings to withstand hurricane-force winds and strong surges, but let the above suffice. Sometimes people learn reactively from tragedies and see the bigger picture only in hindsight.
I confess that I do not know enough about disaster preparedness and response plans in Guyana to even try and imagine a coastal disaster scenario and its aftermath. I know the Civil Defence Commission has some literature on this aspect, and that there is a document titled ‘National Multi-Hazard Disaster Preparedness and Response Plan – Guyana’. The latter appears to be a fairly comprehensive document, but words are words; water and wind can be most unkind.
In the end only time, and maybe an actual disaster, will tell. Should a hurricane or tsunami strike with little, or even adequate, warning, how will we react? May we never have to answer that question.