Barisan Mountains

Barisan Mountains (Indonesian Pegunungan Barisan), volcanic mountain chain extending for about 1,705 km (about 1,060 mi) along the length of the island of Sumatra, in Indonesia. The Barisan lie near the western edge of the island and form one of Sumatra’s three parallel land regions. The northern third of the range is commonly referred to as the Batak and Atjeh Highlands. The western slopes of the Barisan drop sharply to the sea or to low-lying coastal plains up to about 32 km (about 20 mi) in width. To the east the mountains slope more gradually to a parallel zone of rolling hills composed of volcanic and sedimentary rocks. Alluvial coastal lowlands lie farther east. Elevations in the Barisan generally exceed 610 m (2,000 ft). The highest peak is Kerinci, which rises 3,805 m (12,484 ft) in the central part of the range. Much of the Barisan is made up of young lava rock and volcanic ash. There are more than 20 volcanic cones, about half of them active. Merapi (2,911 m/9,551 ft) is the most active volcano in the Barisan and on Sumatra; it has erupted regularly since the 18th century.