Geography

El Salvador is located in Central America. It has a total area of 21,040 sq km (8,123 sq mi), making it the 152nd largest country in the world and comparable in size to (although slightly larger than) Wales. El Salvador is the smallest country in continental America. Due to its size it is affectionately called the 'Tom Thumb of the Americas' (Pulgarcito de America).

The geography of El Salvador is unique among the nations of Central America. The country borders the North Pacific Ocean to the south and southwest, with Guatemala to the north-northwest and Honduras to the north-northeast. In the southeast, the Golfo de Fonseca separates it from Nicaragua. El Salvador shares borders with Guatemala - 126 miles (203 km) and Honduras - 212.5 miles (342 km), and is the only Central American country that does not have a Caribbean coastline. The highest point in the country is Cerro El Pital at 8,957 feet (2,730 metres).

It has 320 sq km (123.6 sq mi) of water within its borders. Several small rivers flow through El Salvador into the Pacific Ocean, including the Goascorán, Jiboa, Torola, Paz and the Río Grande de San Miguel. Only the largest river, the Lempa River, flowing from Honduras across El Salvador to the ocean, is navigable for commercial traffic. Volcanic craters enclose lakes, the most important of which are Lake Ilopango (70 sq km/27 sq mi) and Lake Coatepeque (26 sq km/10 sq mi). Lake Güija is El Salvador's largest natural lake (44 sq km/17 sq mi). Several artificial lakes were created by the damming of the Lempa, the largest of which is Embalse Cerrón Grande (350 sq km/135 sq mi).

Geology

El Salvador, along with the rest of Central America (a region comprising mainly Mexico and Central America), is one of the most seismologically active regions on earth, situated atop three of the large tectonic plates that constitute the earth's surface. The motion of these plates causes the area's earthquake and volcanic activity.

Most of Central America and the Caribbean Basin rests on the relatively motionless Caribbean Plate. The Pacific Ocean floor, however, is being carried northeast by the underlying motion of the Cocos Plate. Ocean floor material is largely composed of basalt, which is relatively dense; when it strikes the lighter granite rocks of Central America, the ocean floor is forced down under the land mass, creating the deep Middle America Trench that lies off the coast of El Salvador. The subduction of the Cocos Plate accounts for the frequency of earthquakes near the coast. As the rocks constituting the ocean floor are forced down, they melt, and the molten material pours up through weaknesses in the surface rock, producing volcanoes and geysers.

North of El Salvador, Mexico and most of Guatemala are riding on the westward-moving North American Plate that butts against the northern edge of the stationary Caribbean Plate in southern Guatemala. The grinding action of these two plates creates a fault, similar to the San Andreas fault in California, that runs the length of the valley of the Rio Motagua in Guatemala. Motion along this fault is the source of earthquakes in northernmost El Salvador.

El Salvador has a long history of destructive earthquakes and volcanic eruptions. San Salvador was destroyed in 1756 and 1854, and it suffered heavy damage in the 1919, 1982, and 1986 tremors. The country has over twenty volcanoes, although only two, San Miguel and Izalco, have been active in recent years. From the early nineteenth century to the mid 1950s, Izalco erupted with a regularity that earned it the name 'Lighthouse of the Pacific.' Its brilliant flares were clearly visible for great distances at sea, and at night its glowing lava turned it into a brilliant luminous cone.

Physical Features

Two parallel mountain ranges cross El Salvador east to west with a central plateau between them and a narrow coastal plain hugging the Pacific. These physical features divide the country into two physiographic regions. The mountain ranges and central plateau, covering 85 percent of the land, comprise the interior highlands. The remaining coastal plains are referred to as the Pacific lowlands.

Interior Highlands

The northern range of mountains, the Sierra Madre, form a continuous chain along the border with Honduras. Elevations in this region range from 1,600 to 2,200 metres. The area was once heavily forested, but overexploitation led to extensive erosion, and it has become semi-barren. As a result, it is the country's most sparsely populated zone, with little farming or other development.

The southern range of mountains is actually a discontinuous chain of more than 20 volcanoes, clustered into 5 groups. The westernmost group, near the Guatemalan border, contains Izalco and Santa Ana, which at 2,365 metres is the highest point in El Salvador. Between the cones lie alluvial basins and rolling hills eroded from ash deposits. The volcanic soil is rich, and much of El Salvador's coffee is planted on these slopes.

The central plateau constitutes only 25% of the land area but contains the heaviest concentration of population and the country's largest cities. This plain is about 50 kilometres wide and has an average elevation of 600 metres. Terrain here is rolling, with occasional escarpments, lava fields and geysers.

Pacific Lowlands

A narrow plain extends from the coastal volcanic range to the Pacific Ocean. This region has a width ranging from one to 32 km with the widest section in the east, adjacent to the Golfo de Fonseca. Near La Libertad, however, the mountains pinch the lowlands out; the slopes of adjacent volcanoes come down directly to the sea. Surfaces in the Pacific lowlands are generally flat or gently rolling and result from alluvial deposits from nearby slopes.

Rivers and Lakes

El Salvador has over 300 rivers, the most important of which is the Rio Lempa. Originating in Guatemala, the Rio Lempa cuts across the northern range of mountains, flows along much of the central plateau, and finally cuts through the southern volcanic range to empty into the Pacific. It is El Salvador's only navigable river, and it and its tributaries drain about half the country. Other rivers are generally short and drain the Pacific lowlands or flow from the central plateau through gaps in the southern mountain range to the Pacific.

Numerous lakes of volcanic origin are found in the interior highlands; many of these lakes are surrounded by mountains and have high, steep banks. The largest lake, the Lago de Ilopango, lies just to the east of the capital. Other large lakes include the Lago de Coatepeque in the west and the Lago de Güija on the Guatemalan border. The Cerron Grande Dam on the Rio Lempa has created a large reservoir, the Embalse Cerron Grande, in northern El Salvador.