IN THE KNOW: Mt. Bulusan

Bulusan Volcano stands 1,559 meters above sea level with a base area of approximately 400 square kilometers.

Five towns—Bulusan, Irosin, Juban, Casiguran and Gubat—share boundaries around the volcano, which lies near the central part of Sorsogon province at the southern portion of the Bicol Peninsula.

Bulusan cradles four craters on its summit, with most eruptions considered phreatic or steam driven characterized by ash explosions.

It hosts two lakes. One is the more popular Lake Bulusan, located at the southeastern side of the volcano at 335 masl. Lake Bulusan is a developed tourist site with a trail around its 2,000-m circumference and boating facilities on its 33-m deep waters. The other lake, Aguingay, is situated at 940 masl.

The earliest recorded eruption of Bulusan was in 1852. Other eruptions recorded before the 20th century included those in 1886, 1889, 1892 and 1894.

Bulusan lulled for 22 years and erupted again on Jan. 18, 1916. Its behavior was characterized by small explosions, minor ash fall, landslides and mud ejection.

A series of phreatic eruptions occurred from 1918 to 1922, which caused little or no damage to the surrounding towns. Bulusan emitted lava in 1918, and erupted again in June 1928 and December 1933.

After 45 years, it  suddenly spewed ash-streaked steam on July 29, 1978. Other eruptions followed in 1979-1980, 1981, 1983, 1988, 1994-1995, 2006-2007, 2011, 2015 and 2016.

Source: Philippine Volcanology, and Seismology