Trinidad & Tobago - Geography
Trinidad and Tobago are the southernmost islands of the Lesser Antilles, located close to the South American continental shelf. Trinidad lies 11 kilometers off the northeast coast of Venezuela and 130 kilometers south of the Grenadines. It is 60 kilometers long and 80 kilometers at its maximum breadth and comprises an area of 4,828 square kilometers. Trinidad appears rectangular in shape with three projecting peninsular corners.
Tobago is located thirty kilometers northeast of Trinidad, from which it is separated by a channel thirty-seven kilometers wide. The island is 42 kilometers long and 13 kilometers wide, with a total area of 300 square kilometers. Tobago is cigar-shaped in appearance and has a northeast-southwest alignment. Outside of the urban areas, the islands are both covered with lush green vegetation. There are beaches throughout, and Tobago has a coral reef where a variety of tropical fish can be found.
Geologically, the islands are not part of the Antillean arc. Rather, Trinidad was once part of the South American mainland, and Tobago is part of a sunken mountain chain related to the continent. The islands are now separated from the continent of South America by the Gulf of Paria; a nineteen-kilometer-wide northern passage-Dragon's Mouths; and a fourteen-kilometer-wide southern passage - Serpent's Mouth.
Trinidad is traversed by three distinct mountain ranges that are a continuation of the Venezuelan coastal cordillera. The Northern Range, an outlier of the Andes Mountains of Venezuela, consists of rugged hills that parallel the coast. This range rises into two peaks. The highest, EI Cerro del Aripo, is 940 meters high; the other, EI Tucuche, reaches 936 meters. The Central Range extends diagonally across the island and is a low-lying range with swampy areas rising to rolling hills; its maximum elevation is 325 meters. The Caroni Plain, composed of alluvial sediment, extends southward, separating the Northern Range and Central Range. The Southern Range consists of a broken line of hills with a maximum elevation of 305 meters.
There are numerous rivers and streams on the island of Trinidad; the most significant are the Ortoire River, fifty kilometers long, which extends eastward into the Atlantic, and the forty-kilometer long Caroni River, reaching westward into the Gulf of Paria. Most of the soils of Trinidad are fertile, with the exception of the sandy and unstable terrain found in the southern part of the island.
Tobago is mountainous and dominated by the Main Ridge, which is 29 kilometers long with elevations up to 640 meters. There are deep, fertile valleys running north and south of the Main Ridge. The southwestern tip of the island has a coral platform. Although Tobago is volcanic in origin, there are no active volcanoes. Forestation covers 43 percent of the island. There are numerous rivers and streams, but flooding and erosion are less severe than in Trinidad. The coastline is indented with numerous bays, beaches, and narrow coastal plains.
Tobago has several small satellite islands. The largest of these, Little Tobago, is starfish shaped, hilly, and consists of 120 hectares of impenetrable vegetation.
There are four mineral springs and several mud volcanoes, but the two most striking natural features are the Maracas Falls, and the Pitch Lake. The Maracas Falls are situated at the head of a valley of the same name, to the north-east of Port of Spain, where the river leaps in a foaming torrent over a sheer wall of rock 312 ft. high. The Pitch Lake lies some 38 m. by water south-east of the capital, in the ward of La Brea. It is circular in form, about 3 m. in circumference, and about 100 acres in extent. Underground forces acting on the pitch cause it to rise in unequal masses, which are rounded off like huge mushrooms, separated from one another by narrow fissures, in which the rainwater collects and forms pools. Near the center of the lake the pitch is always soft and can be observed bubbling up in a liquid state. When the sun is hot the lightest footfall leaves an impression and the pitch emits an unpleasant odour. The soil of the surrounding district is charged with asphalt, but is very fertile, while the road to the neighboring port of La Brea, running on a bed of asphalt, moves slowly towards the sea like a glacier.
The celebrated Pitch Lake of Trinidad was long regarded as the largest deposit of asphalt in existence, but it is said to be exceeded in area, if not in depth also, by one in Venezuela. The Trinidad “Lake” was sufficiently firm in places to support a team of horses. In the years before the Great War the deposit was worked with picks to a depth of a foot or two, and the excavations soon become filled up by the plastic material flowing in from below and hardening. The depth of the deposit was not accurately known.
The surface was not level but is composed of irregularly tumescent masses of various sizes, each said to be subject to independent motion, whereby the interior of each rose and flowed centrifugally towards the edges. As the spaces between them were always filled with water, these masses were prevented from coalescing. The softer parts of the lake constantly evolved gas, which was stated to consist largely of carbon dioxide and sulphuretted hydrogen, and the pitch, which was honeycombed with gas-cavities, continued to exhibit this action for some time after its removal from the lake.
The working of the deposit was in the hands of the New Trinidad Asphalt Company, who held the concession up to the year 1930 on payment to the government of a minimum royalty of £10,000 a year. A circular line of tramway, supported on palm-leaves, had been laid on the lake to facilitate the removal of the asphalt. Very large quantities were exported for paving and other purposes, the annual shipments amounting to about 130,000 tons from the lake and about 30,000 tons from other properties.
T&T has been rated in the “extremely vulnerable” category for seismic activity. The 2011 University of West Indies (UWI) Seismic Research Center Annual Report indicated that seismic activity remains elevated in the Paria Penninsula (extends eastward off Venezuela toward Trinidad). In 1955, an earthquake occurred north of Trinidad, which UWI deemed would have been catastrophic if it occurred in the same location within the islands’ current topography. The same report indicated that in 2011 four earthquakes considered “moderate,” measuring 5.1 on the Richter scale, occurred near T&T. In October 2013, a magnitude 6.4 earthquake off the coast of Venezuela was widely felt in T&T; there were no reports of damage.
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