Bulusan
Bulusan is a stratovolcano with a peak elevation of 1,312 meters above sea level and a basal width of 8.92 kilometers. It is the fourth most active volcano in the Philippines after Mayon, Taal, and Kanlaon. Mayon is a nearby volcano and only 68 km. away to the northwest of Bulusan. Its most recent eruption was from June 5, 2022 to June 12, 2022 . Since 1852, Bulusan has experienced a total of 23 eruptions, although the earliest documented eruption remains uncertain according to the Smithsonian Global Volcano Database. Out of the 25 recorded eruptions, radiocarbon dating of previous deposits indicates two additional eruptions occurring in 950 BC and 30,350 BC. Over the last two centuries, most of Bulusan’s eruptions have been classified with a Volcanic Explosivity Index (VEI) of 2, with only two eruptions reaching a VEI of 3.
Bulusan Volcano is part of the Bulusan volcanic complex, a northwest-southeast trending chain of Pliocene-Quaternary volcanoes situated at the southern end of the Bicol Volcanic Arc. The most notable feature within this complex is the expansive 11-kilometer volcano-tectonic structure known as the Irosin Caldera. Surrounding the Irosin Caldera are various lava domes and cones. The Jormahan lava dome is situated on the southwest ridge, while Sharp Peak rises prominently on the northeast side. A wide, flat moat can be found along the southeast rim of the caldera, whereas the northeast rim is characterized by volcanic deposits of andesitic composition. The Bulusan volcanic complex is fed by magma generated from the westward subduction of the Philippine Sea plate at the Philippine Trench.
The legend of Si Bulusan nan si Agingay: Iyak ni Mampak tells the story of the lakes and the active volcano in Irosin. It originates from the town of Sorsogon, surrounding the mystical Bulusan Volcano and Bulusan Lake. In this tale, a brave and handsome man, named Bulusan lived blissfully under the shadow of a volcano with his beautiful wife Agingay. One day, a jealous neighbor named Casiguran, blamed Bulusan for the bloody murder of his father. Wrongfully accused, authorities sentenced Bulusan to death from the ferocious Mampak, a giant man-eating bird. Not content with the death of Bulusan, Casiguran forced Agingay to throw her newborn son into the fiery crater of a volcano. Grief-stricken, Agingay took her life. Outraged by their discovery of the truth after the death of Bulusan’s entire family, the villagers threw Casiguran into the same fire pit. The tears and blood that were shed by the couple gave rise to lakes, now referred to by the locals as Lake Bulusan and Lake Agingay. Residents of the municiplity of Bulusan reenact the legend of the beautiful couple through a yearly street-dancing festival held every 24th of July. Students dressed in Abaca dance around town, grooving to the beat of drums made of bamboo.
Other Names: Balusan
Latitude and Longitude: 12.76897 124.05651
Region: Region 5
Tectonic Setting: Subduction (Philippine Trench)
Volcanic Arc/Belt: East Philippine Volcanic Arc
Volcanic Region/Field: Bicol Volcanic Region
Volcano Type: Stratovolcano, Caldera, Lava dome(s)
Last Known Eruption: June 12, 2022 3:37 AM
Morphometry Type: Sub-cone
Highest Peak (masl): 1,565
Coordinates of Highest Peak: 12.76897 124.05651
Prominence (m): –
Basal Area (km2): 62.4
Basal Width (km): 8.92
Volume (km3): 24
How to cite this page:
UPRI (2025) Bulusan: Volcanoes of the Philippines (NOAH Open File Reports). Distributed by the University of the Philippines Resilience Institute, written by Jolly Joyce Sulapas. ISSN 2362 7409.
References:
Bornas, M.A.V., Rivera, D.J.V., Pidlaoan, A.C., Cahulogan, M.T., & Nadua, J.H. (2016). Bulusan Volcano Danger Zones Map. in: Volcanic Hazard Assessment for Bulusan Volcano. Internal Report, Philippine Institute of Volcanology and Seismology (PHIVOLCS).
Bornas, M.A.V., Rivera, D.J.V., Pidlaoan, A.C., Cahulogan, M.T., & Nadua, J.H. (2016). Bulusan Volcano Lava Flow Hazard Map. in: Volcanic Hazard Assessment for Bulusan Volcano. Internal Report, Philippine Institute of Volcanology and Seismology (PHIVOLCS).
Bornas, M.A.V., Rivera, D.J.V., Pidlaoan, A.C., Cahulogan, M.T., & Nadua, J.H. (2016). Bulusan Volcano Pyroclastic Density Current Hazard Map. in: Volcanic Hazard Assessment for Bulusan Volcano. Philippine Institute of Volcanology and Seismology (PHIVOLCS).
Clotario, D. (2012, January). Si Bulusan nan si Agingay: Iyak ni Mampak. Behance. https://www.behance.net/gallery/2920469/Si-Bulusan-nan-si-Agingay-Iyak-ni-Mampak
Delfin Jr., F. G., Panem, C. C., Defant, M. J. (1993) – Eruptive History and Petrochemistry of the Bulusan Volcanic Complex: Implications for the Hydrothermal System and Volcanic Hazards of Mt. Bulusan, Philippines.
Delos Reyes, P. J., Bornas, M. A. V., Arpa, M. C. B., Laguerta, E., Cahulogan, M. T., Maximo, R. P. R., Mirabueno, M. H. T., Perez, J. S., Tubianosa, B. S., Solidum, R. U. (2014) – Fallout Tephras of the 2006-2007 Eruptions of the Bulusan Volcano, Southern Luzon, Philippines. doi:10.5026/jgeography.124.761
Global Volcanism Program, 2024. Bulusan (273010) in [Database] Volcanoes of the World (v. 5.2.1; 3 Jul 2024). Distributed by Smithsonian Institution, compiled by Venzke, E. https://doi.org/10.5479/si.GVP.VOTW5-2024.5.2
Engielle Mae Paguican. The structure, morphology, and surface texture of debris avalanche deposits : field and remote sensing mapping and analogue modelling. Earth Sciences. Université Blaise Pascal – Clermont-Ferrand II, 2012. English.
McDermott, F., Delfin Jr., F. G., Defant, M. J., Turner, S., Maury, R., (2005) – The petrogenesis of volcanics from Mt. Bulusan and Mt. Mayon in the Bicol arc, the Philippines. Contr Mineral Petr, 150: 652-670. DOI: 10.1007/s00410-005-0042-7
Paguican, E.M., Grosse, P., Fabbro, G.N., Kervyn, M. (2021) – Morphometric classification and spatial distribution of Philippine volcanoes. https://doi.org/10.1016/j.jvolgeores.2021.107251
PHIVOLCS-LAVA Eruption History. https://wovodat.phivolcs.dost.gov.ph/volcano/erupt-history
Rivera, D.J.V., Bornas, M.A.V., Pidlaoan, A.C., Cahulogan, M.T., & Nadua, J.H. (2016). Bulusan Volcano Lahar Hazard Map. in: Volcanic Hazard Assessment for Bulusan Volcano. Internal Report, Philippine Institute of Volcanology and Seismology (PHIVOLCS).