By C. Roy Reynolds, Contributor
PICTURE THE following scenario: It has been raining steadily for most of the past three days... It is night and most people in and around the city of Kingston are safe in their homes. But somewhere up there in the hills above something has been moving slightly, unnoticed by any human eye... Suddenly in the dead of night a critical state has been reached and the object hurtles downward, gaining momentum by the second.
The big problem is that this is a 600-ton boulder and it has the city below in its sights. Yet this is not the only scenario or even the worst. It could happen in the course of a busy day and owe its launch not to flood but to an earthquake. And our 600-ton boulder might have company, perhaps smaller but not less deadly.
How do we know that this could happen? Because scientific data suggest that it happened before. One only has to observe the size and number of the boulders unearthed recently by the reconstruction work on the Hope Road. Research carried out in the area as long as 1963 concluded that "top beds of the Liguanea gravels are characterised by the presence of enormous boulders weighing up to 600 tons, many of which have been transported four miles across the plain from Papine." It was further established that these features were not transported by running water as most alluvial deposits are but more likely through the agency of landslide action.
Landslides
All around the city and far into the countryside are features which seem ready-made for landslides of varying intensity. So far within living memory although there have been numerous landslides in and around Kingston they have not caused serious loss of life though the cumulative damage caused to property and infrastructure such as roads and water supplies has been substantial. But cataclysmic disaster tends to run in cycles which for convenience might be termed 50 years, 100-year or 500-year affairs. Not that these can be timed exactly to fit into these time frames chronologically. But the statistical analysis suggests these time frames.
As far as catastrophic landslides due to seismic activity are concerned the earliest records are from the great earthquake of 1692 which destroyed Port Royal. Unfortunately, the drama of Port Royal's demise tends to push aside recognition of other effects of this catastrophe. For example the massive land dislocation that occurred does not form part of today's consciousness of that event. Yet a later record indicates the following passage:-
"The Blue and others of the highest mountains are declared to have been strangely torn and rent. They appeared shattered and half-naked no longer affording a fine green prospect as before, but stripped of their woods and natural verdure. The rivers of these mountains ceased to flow for about 24 hours, and then brought down into the sea at Port Royal and other places, several hundred thousands tons of timber, which looked like floating islands on the ocean. The trees were in general barked, most of their branches having been torn in descent."
This must logically be view against the period in which it occurred. At that time there was little by way of human habitation and structures to the east and north of Port Royal. Thus, what occurred in these mountain areas at that time was more of a curiosity phenomenon rather than a record of damage. In today's reality the carnage of a similar occurrence is too gory to contemplate! Yet landslides in the areas surrounding Kingston are almost a constant feature.
They are inherent in the surface as well as the underlying features of the region but there is a critical new factor that enters into the calculation: Human intervention... Even up to the time of the Flora rains of 1963 the hills and slopes above the city were by and large pristine. Their natural vegetative cover was largely intact and human habitation was just marginally intrusive. Today the picture has changed completely.
Most of the area has been drastically altered to accommodate an inexorable urban sprawl. The evidence suggests that while considerable attention has been paid in the process to architectural elegance, environmental issues have been largely ignored. Naturally the proliferation of heavy superstructures on the slopes can have the effect of accelerating the processes which work to produce these periodic visitations, but perhaps more so are the network of roadways and other excavations associated with modern living.
That cataclysmic events have occurred in the past is a matter of historical record and geophysical evidence. In recent years there has been ample evidence of tragic disasters which have occurred in several areas of the world where comparative physical conditions have combined with human recklessness to set the scene for tragedy. It is hard to believe that given all physical conditions that exist plus reckless human intervention to establish the abode of the privileged and to accommodate the dire needs of the less endowed, that we can indefinitely escape the consequences posed by such trespass.
Under the circumstances there is no time left for complacency. The threat is as real, as it is dire. The superficial view may be that only those who have invaded the critical areas are under the gun, so to speak, but those below might be even more at risk.
Courtesy of the Environmental Foundation of Jamaica.
