Mount Bulusan

Mount Bulusan, or Bulusan Volcano, is the southernmost volcano on Luzon Island in the Philippines. It is found in the province of Sorsogon in the Bicol region (12°46.2'N, 124°03'E), 70 km southeast of Mayon Volcano and approximately 250 km southeast of the Philippine capital of Manila.

Physical Features

Bulusan is classified by volcanologists as a stratovolcano (composite volcano) inside a caldera that was formed about 40,000 before the present. It has an elevation of 1,565 meters above sea level and a base diameter of 15 km.

It has four craters and four hot springs. Crater No. 1, called Blackbird Lake, is 20 m in diameter and 15 m deep. The oval Crater No. 2 is 60 m by 30 m and 15 m deep. Crater No. 3 is about 90 m in diameter and 20 m deep and Crater No. 4, which is near the northeastern, rim opened during the 1981 eruption. There is also a 100-meter fissure measuring 5 to 8 m wide below Crater No. 4.

Its hot springs are San Benon Springs, Mapaso Springs, San Vicente Springs, Masacrot Springs

Its adjacent volcanic edifices are Mt. Homahan, Mt. Binitacan, Mt. Batuan, Mt. Calungalan, Mt. Calaunan, Mt. Tabon-Tabon, Mt. Juban and Mt. Jormajan.

Eruptions

Bulusan has erupted 15 times since 1886.

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 Alert Level 2 (moderate level of seismic unrest) after it spewed ash. On June 9, the resulting ash cloud damaged a number of houses in the nearby town of Casiguran, 5 km north of the volcano, and reached Sorsogon City, about 20 kilometers north of Bulusan.

On June 13, 2006, volcanologists said new craters were created by the mild explosions of Mt. Bulusan. Aside from the new craters, two of the volcano's four craters appeared to have merged and cracks were observed on the crater on the western side of the summit.

Bulusan is generally known for its sudden steam-driven or phreatic explosions. It is one of the 22 active volcanoes in the Philippines: Babuyan Claro, Banahaw, Biliran, Bud Dajo, Cagua, Camiguin de Babuyanes, Didicas, Hibok-Hibok, Iraya, Mount Iriga, Mount Kanlaon, Leonard Kniaseff, Makaturing, Matutum, Mayon, Musuan, Mount Parker in Cotabato, Pinatubo, Ragang, Smith, Taal. They are all part of the so-called "Pacific ring of fire."

External links

• Philippine Institute of Volcanology and Seismology (PHIVOLCS) Bulusan Volcano Page
• NASA Earth Observatory satellite image of ash plume at Mount Bulusan
• Smithsonian Insitution's Global Volcanism Program