Mayon one of 6 most active volcanoes in disaster-prone RP

Mount Mayon is one of the six most active volcanoes in "disaster-prone" Philippines that government has placed under close and constant watch, on account of the frequency, recency and grim impact of their eruptions. Apart from Mayon, the Philippine Institute of Volcanology and Seismology (Phivolcs) is also monitoring Taal, Bulusan, Kanlaon, Hibok-Hibok and Pinatubo volcanoes, "which have erupted repeatedly in historical times." "The Philippines," Phivolcs said, "is a disaster-prone country" that hosts more than 200 volcanoes, of which 22 are active. At least five earthquakes per day occur in the archipelago, it added. Mount Pinatubo, which lies on the boundaries of Zambales, Pampanga and Tarlac province, was a dormant volcano until its last violent eruption in June 1991 covered most of Luzon island in a blanket of ash and buried entire towns in mudflow several meters deep. After the eruption, Pinatubo's elevation receded from 1.745 kilometers to 1.445 km, Phivolcs said. In July-October 1992, Pinatubo exhibited "dome-formation activity." Taal volcano in Batangas province has 47 craters and 4 caldera or maars. Its main crater lake that is blue-green in color, volcanologists said, stands 4 meters above sea level. Its last eruption on October 3, 1977 followed nine earlier major eruptions in 1749, 1754, 1878, 1911, 1965, 1966, 1968, 1969, and 1970. Throughout history, Taal has erupted 47 times. Mount Bulusan in Sorsogon province, "a stratovolcano inside a caldera," has 18 recorded eruptions since 1852, the last one occurring on November 27, 1994. In recent months, Bulusan has drawn attention from state volcanologists on account of "rumbling sounds, increased steaming activity, noticeable increase in the extent of drying up of vegetation around the volcano's upper slopes," all phenomena associated with eruption. Kanlaon volcano in Negros Oriental province, also a stratovolcano like Bulusan, has chalked up a record of 21 eruptions, the latest in August 1996. The sixth most active volcano in the country, Hibok-Hibok in Camiguin province, is classified as "a complex volcano." It has five recorded eruptions, the last one from September 1948 to July 1953. - GMANews.TV