Madagascar - Geography

Geography

At 592,800 square kilometres (228,900 sq mi), Madagascar is the world's 47th largest country and the fourth-largest island. The country lies mostly between latitudes 12°S and 26°S, and longitudes 43°E and 51°E. Neighboring islands include the French territory of Réunion and the country of Mauritius to the east, as well as the state of Comoros and the French territory of Mayotte to the north west. The nearest mainland state is Mozambique, located to the west.

The prehistoric breakup of the supercontinent Gondwana separated the Madagascar-Antarctica-India landmass from the Africa-South America landmass around 135 million years ago. Madagascar later split from India about 88 million years ago, allowing plants and animals on the island to evolve in relative isolation. Along the length of the eastern coast runs a narrow and steep escarpment containing much of the island's remaining tropical lowland forest. To the west of this ridge lies a plateau in the center of the island ranging in altitude from 750 to 1,500 m (2,460 to 4,920 ft) above sea level. These central highlands, traditionally the homeland of the Merina people and the location of their historic capital at Antananarivo, are the most densely populated part of the island and are characterized by terraced, rice-growing valleys lying between grassy hills and patches of the subhumid forests that formerly covered the highland region. To the west of the highlands, the increasingly arid terrain gradually slopes down to the Mozambique Channel and mangrove swamps along the coast.

Madagascar's highest peaks rise from three prominent highland massifs: Maromokotro 2,876 m (9,436 ft) on the Tsaratanana Massif is the island's highest point, followed by Boby Peak 2,658 m (8,720 ft) on the Andringitra Massif and Tsiafajavona 2,643 m (8,671 ft) on the Ankaratra Massif. To the east, the Canal des Pangalanes is a chain of man-made and natural lakes connected by canals built by the French just inland from the east coast and running parallel to it for some 600 km (370 mi). The western and southern sides, which lie in the rain shadow of the central highlands, are home to dry deciduous forests, spiny forests, and deserts and xeric shrublands. Due to their lower population densities, Madagascar's dry deciduous forests have been better preserved than the eastern rain forests or the original woodlands of the central plateau. The western coast features many protected harbors, but silting is a major problem caused by sediment from the high levels of inland erosion carried by rivers crossing the broad western plains.