The Soufrière Hills volcano is an active, complex stratovolcano with many lava domes forming its summit, on the Caribbean island of Montserrat. Many volcanoes in the Caribbean are named Soufrière (French: "sulphur outlet"). These include La Soufrière or Soufrière Saint Vincent on the island of Saint Vincent and La Grande Soufrière on Guadeloupe. After a long period of dormancy, the Soufrière Hills volcano became active in 1995, and has continued to erupt ever since. Its eruptions have rendered more than half of Montserrat uninhabitable, destroying the capital city, Plymouth, and causing widespread evacuations: about two thirds of the population have left the island.It is andesitic in nature and the current pattern of activity includes periods of lava dome growth, punctuated by brief episodes of dome collapse which result in pyroclastic flows, ash venting, and explosive eruption. The volcano is monitored by the Montserrat Volcano Observatory. Volcanic gas emissions from this volcano are measured by a Multi-Component Gas Analyzer System, which detects pre-eruptive degassing of rising magmas, improving prediction of volcanic activity.