Mount Bulusan, also known as Bulusan Volcano, is a stratovolcano on the island of Luzon in the Philippines. Located in the province of Sorsogon in the Bicol Region, it is southeast of Mayon Volcano and approximately southeast of the Philippine capital of Manila. It is one of the active volcanoes in the Philippines. Physical features Bulusan is classified by volcanologists as a stratovolcano (or a composite cone) and covers the northeast rim of Irosin caldera that was formed about 40,000 years ago. It has a peak elevation of above sea level with a base diameter of . Around the mountain are four craters and four hot springs. The first crater, called Blackbird Lake, is in diameter and deep. The second crater is oval, with dimensions of and . The third crater is about in diameter and deep, while the fourth, which is near the northeastern rim opened during the 1981 eruption. There is also a fissure measuring wide below this crater. The volcano's hot springs are: Mapaso Masacrot San Benon San Vicente Adjacent volcanic edifices are: Mount Batuan Mount Binitacan Mount Calaunan Mount Calungalan Mount Homahan Mount Jormajan Mount Juban Mount Tabon-Tabon Eruptions Bulusan is generally known for its sudden, steam-driven or phreatic explosions. It has erupted 15 times since 1885 and is the fourth most active volcano in the Philippines after Mayon, Taal, and Kanlaon. Evacuation procedures There are evacuation procedures in place for parts of the peninsula; the farms nearest the volcano are to be evacuated, and many village schools will be closed if a more destructive eruption is possible. Recent activity March–June 2006 The Philippine Institute of Volcanology and Seismology (PHIVOLCS) declared alert level 1 on March 19, 2006, after it recorded increased seismic unrest. On June 8, 2006, volcanologists raised the alert level to 2 (moderate level of seismic unrest) after the volcano spewed ash. On June 9, the resulting ash cloud damaged a number of houses in the nearby town of Casiguran, north of the volcano, and reached Sorsogon City, about north of Bulusan. On June 13, 2006, volcanologists said new craters were created by mild explosions. Aside from the new craters, two of the volcano's existing four craters appeared to have merged and cracks were observed on the western rim of the summit crater. Another eruption took place on April 8, 2007. July–October 2007 Following some signs of volcanic activity, on the morning of