Chapter 2
The Maracaibo System: A Physical Profile
Gilberto Rodriguez
2.1
Introduction
Intermontane basins are areas of potential oil accumulation (Hyne and Dickey 1977).
The Maracaibo Basin, located on the northern front of South America, is no exception: It is the most important oil accumulation in South America and one of
the largest in the world. From 1914 to 1995 the total amount of oil extracted from the
basin was 33 000 millions barrels (5238 x 10 6 m3). Most of this production comes from
the bottom of Lake Maracaibo itself, the largest lake in South America and the 1ih in
the world.
The oil interests, together with the large yield of the fisheries in the estuary, more
than 40000 t yr-l, and the accelerated demographic growth, has fostered, since the
middle 1950S, a large body of research addressed mostly to two practical problems of
management, viz. the possibilities of a process of salinization of the lake caused by
the dredging of its bar, and the potential eutrophication of the whole body of water
from sewage, pollution and other nutrient-rich sources. Several large scale engineering projects have been considered to alleviate the salinity intrusion through the navigation channels, but as all these imply drastic changes in port facilities and ship routes
used at present (Rodriguez 1984), they have to be framed within a program of integrated coastal zone management (Conde and Rodriguez in press).
Most of the research dealing with these problems has been published in private
reports to the government and oil companies, and only a small fraction went to main
stream journals. The present contribution summarizes the physical framework of the
estuary, as discerned through these studies.
2.2
Geomorphology
The large orographic system of the Andes on its northern-most portion is divided into
two distinct ranges: the Venezuelan Andes to the north-east and the Sierra de Perija
to the north, forming between them a large pocket of lowlands. This extensive platform has an approximate oval shape, as does the central Lake Maracaibo which acts
as reservoir for all the drainage of the surrounding sierras (Fig. 2.1). Lake Maracaibo
is a body of water 150 km long and 90 km wide, connected to the sea by the Strait of
Maracaibo, a narrow channel about 60 km long and 15 m deep. To the north the Strait
open into Tablazo Bay, which is about 27 km wide and 20 km long. Recent marine sediments deposited in the lake have reduced its depth to less than 40 m (Gonzalez de
Juana et al. 1980).
The Maracaibo System: A Physical Profile
Gilberto Rodriguez
2.1
Introduction
Intermontane basins are areas of potential oil accumulation (Hyne and Dickey 1977).
The Maracaibo Basin, located on the northern front of South America, is no exception: It is the most important oil accumulation in South America and one of
the largest in the world. From 1914 to 1995 the total amount of oil extracted from the
basin was 33 000 millions barrels (5238 x 10 6 m3). Most of this production comes from
the bottom of Lake Maracaibo itself, the largest lake in South America and the 1ih in
the world.
The oil interests, together with the large yield of the fisheries in the estuary, more
than 40000 t yr-l, and the accelerated demographic growth, has fostered, since the
middle 1950S, a large body of research addressed mostly to two practical problems of
management, viz. the possibilities of a process of salinization of the lake caused by
the dredging of its bar, and the potential eutrophication of the whole body of water
from sewage, pollution and other nutrient-rich sources. Several large scale engineering projects have been considered to alleviate the salinity intrusion through the navigation channels, but as all these imply drastic changes in port facilities and ship routes
used at present (Rodriguez 1984), they have to be framed within a program of integrated coastal zone management (Conde and Rodriguez in press).
Most of the research dealing with these problems has been published in private
reports to the government and oil companies, and only a small fraction went to main
stream journals. The present contribution summarizes the physical framework of the
estuary, as discerned through these studies.
2.2
Geomorphology
The large orographic system of the Andes on its northern-most portion is divided into
two distinct ranges: the Venezuelan Andes to the north-east and the Sierra de Perija
to the north, forming between them a large pocket of lowlands. This extensive platform has an approximate oval shape, as does the central Lake Maracaibo which acts
as reservoir for all the drainage of the surrounding sierras (Fig. 2.1). Lake Maracaibo
is a body of water 150 km long and 90 km wide, connected to the sea by the Strait of
Maracaibo, a narrow channel about 60 km long and 15 m deep. To the north the Strait
open into Tablazo Bay, which is about 27 km wide and 20 km long. Recent marine sediments deposited in the lake have reduced its depth to less than 40 m (Gonzalez de
Juana et al. 1980).