Caribbean Islands - Geographic Setting

Geographic setting

The Commonwealth Caribbean islands make up a large subcomponent of the hundreds of islands in the Caribbean Sea, forming a wide arc between Florida in the north and Venezuela in the south, as well as a barrier between the Caribbean Sea and the Atlantic Ocean. Varying considerably in size, the islands, which are the isolated upper parts of a submerged chain of volcanic mountains, are scattered over thousands of square kilometers of sea. The entire region lies well within the northern tropics.

The three principal geological formations found throughout the Caribbean are igneous and metamorphic rocks, limestone hills or karst, and coastal, sedimentary plains of varying depths, resulting in three prevailing types of topography, found either separately or in combination. The first consists of high (over 1,200 meters), rugged, sharply dissected mountains--such as the Blue Mountains in eastern Jamaica, the Morne Diablotins in central Dominica, the Pitons in St. Lucia, and the Northern Range in Trinidad--all covered with dense, evergreen rain forests and cut by swiftly flowing rivers. The second typography consists of very hilly countryside, such as the high plateau of central Jamaica, or the islands of St. Kitts, Antigua, and Barbados. There the hills seldom rise above 600 meters and are more gently sloped than the high mountains, but karst areas are still rugged. Finally, the coastal plains skirt the hills and mountains, with their greatest extensions usually on the southern or western sides of the mountains. Active volcanoes exist in Dominica, St. Vincent, and St. Lucia, and there are crater lakes formed by older activity in Grenada. All the islands have rugged coastlines with innumerable inlets fringed by white or dark sands (depending on the rock substratum ) of varying texture. The beaches of Negril, Jamaica, and Grand Anse, Grenada, have fine-textured white sands that extend for nearly eleven kilometers each.

The Caribbean climate is tropical, moderated to a certain extent by the prevailing northeast trade winds. Individual climatic conditions are strongly dependent on elevation. At sea level there is little variation in temperature, regardless of the time of the day or the season of the year. Temperatures range between 24°C and 32°C. In Kingston, Jamaica, the mean temperature is 26°C, whereas Mandeville, at a little over 600 meters high in the Carpenters Mountains of Manchester Parish, has recorded temperatures as low as 10°C. Daylight hours tend to be shorter during summer and slightly longer during winter than in the higher latitudes. The conventional division, rather than the four seasons, is between the long rainy season from May through October and the dry season, corresponding to winter in the northern hemisphere.

Even during the rainy period, however, the precipitation range fluctuates greatly. Windward sides of islands with mountains receive much rain, whereas leeward sides can have very dry conditions. Flat islands receive slightly less rainfall, but its pattern is more consistent. For example, the Blue Mountains of eastern Jamaica record around 558 centimeters of rainfall per year, whereas Kingston, on the southeastern coast, receives only 399 centimeters. Bridgetown, the capital of Barbados, has an average annual rainfall of 127 centimeters, while Bathsheba on the central east coast receives 254 centimeters--despite the fact that Bathsheba is only about 27 kilometers away by road. Recording stations in the Northern Range in Trinidad measure some 302 centimeters of rainfall per year, while at Piarco Airport on the Caroni Plains the measurement is only 140 centimeters. Most of the rainfall occurs during short heavy outbursts during daylight hours. In Jamaica, about 80 percent of the rainfall occurs during the day. The period of heaviest rainfall usually occurs after the sun has passed directly overhead, which in the Caribbean islands would be sometime around the middle of May and again in early August. The rainy season also coincides with the disastrous summer hurricane season, although Barbados, too far east, and Trinidad and Tobago, too far south, seldom experience hurricanes.

Hurricanes are a constant feature of most of the Caribbean, with a "season" of their own lasting from June to November. Hurricanes develop over the ocean (usually in the eastern Caribbean) during the summer months when the sea surface temperature is high (over 27°C) and the air pressure falls below 950 millibars. These conditions create an "eye" about 20 kilometers wide, around which a steep pressure gradient forms that generates wind speeds of 110 to 280 kilometers per hour. The diameter of hurricanes can extend as far as 500 to 800 kilometers and produce extremely heavy rainfalls as well as considerable destruction of property. The recent history of the Caribbean echoes with the names of destructive hurricanes: Janet (1955), Donna (1960), Hattie (1961), Flora (1963), Beulah (1967), Celia and Dorothy (1970), Eloise (1975), David (1979), and Allen (1980).

The natural resources of the Commonwealth Caribbean islands are extremely limited. Jamaica has extensive deposits of bauxite, some of which is mined and processed locally into alumina, with the United States being the largest market for the bauxite and alumina. In addition, Jamaica has large quantities of gypsum. Trinidad and Tobago has petroleum, pitch, and natural gas. Small, noncommercially viable deposits of manganese, lead, copper, and zinc are found throughout most of the islands. Nevertheless, most of the territories possess nothing more valuable than beautiful beaches, marvelously variegated seas, and a pleasant climate conducive to the promotion of international tourism.

Industrialization varies from territory to territory, but agriculture is generally declining on all the islands. The sugar industry, once the mainstay of the Caribbean economies, has faltered. Although the labor force employed in sugar production (and in agriculture in general) still forms the major sector of the employed labor force in Barbados and Jamaica, the contribution that sugar makes to the gross domestic product (GDP--see Glossary) has steadily dropped. Barbados has kept its sugar industry going, but it has steadily reduced dependence on sugar exports and diversified its economy. For example, in 1946 Barbados had 52 sugar factories producing nearly 100,000 tons of sugar and employing more than 25,000 persons during crop-time. Although production had increased by 1980, the number of factories had declined to eight, and the number employed was slightly less than 9,000. Furthermore, the proportion of GDP contributed by sugar and sugar products had declined from 37.8 percent to 10.9 percent over the same period.

Since the 1950s, light manufacturing, mining, and processing of foods and other commodities have been used to bolster employment and increase the local economies. Although these sectors have been important contributors to the GDP of the individual states, in no case does this contribution exceed 20 percent of the total. Moreover, industrialization has provided neither sufficient jobs nor sufficient wealth for the state to offset the decline in agricultural production and labor absorption.

The Commonwealth Caribbean islands, like the rest of the region (except Cuba), find themselves in a difficult trading situation with the United States. From the regional perspective, the United States accounts for between 20 and 50 percent of all imports and exports. On the other hand, the Commonwealth states account for less than 1 percent of all United States imports and exports and less than 5 percent of the more than US$38 billion of overseas private investment in the Western hemisphere. But the interest in the Commonwealth Caribbean islands cannot be measured in economic terms only. The Caribbean is clearly within the American sphere of interest for political and strategic considerations that defy economic valuation.

Caribbean - Wikipedia
Island Destinations Rated: Caribbean @ National Geographic
Caribbean Facts - Softschools.com
Caribbean Landforms and Land Statistics - WorldAtlas.com