VOLCANOES IN THE PHILIPPINES: ACTIVE ONES, GEOLOGY, ERUPTIONS, WORLD’S LARGEST CALDERA

VOLCANOES IN THE PHILIPPINES

from the Philippine Institute of Volcanology and Seismology

The Philippines lies along the Pacific "Ring of Fire," where volcanic activity and earthquakes are common. About 24 out of the roughly 300 volcanoes in the archipelago are active according to the Philippine Institute of Volcanology and Seismology (PHIVOLCS). These include Mayon (Albay Province in southern Luzon), Mounts Pinatubo (Central Luzon) and Taal (Batangas in southern Luzon). By some reckonings the southern part of the Philippines island of Luzon has more active volcanoes per square kilometer than any other place. A supervolcano erupted at Taal within the last 2 million years. PHIVOLCS monitors volcanic activity in the Philippines and defines "active" as volcanoes that have erupted in the past 500 years. In addition to th ones named above, these include Biliran, Babuyan Claro, Bulusan, Camiguin, Camiguin de Babuyanes, Didicas, Iraya, Jolo, Kanlaon, Makaturing, Musuan, Parker, and Ragang.

Most of the active volcanoes in the Philippines are stratovolcanoes — steep-sided, cone-shaped volcanic mountains formed by layers of lava, ash, and other volcanic materials. These volcanoes have shaped the country's dramatic landscapes, from the mountains of Luzon in the north to the highlands of Mindanao in the south. The abundance of volcanoes in the Philippines is the result of its location within the Pacific Ring of Fire, a vast horseshoe-shaped zone surrounding the Pacific Ocean . The archipelago lies at the meeting point of several tectonic plates, particularly the Philippine Sea Plate and the Eurasian Plate. As these massive plates move toward one another, the denser oceanic crust is forced beneath the lighter crust in a process known as subduction. Deep beneath the Earth's surface, the descending plate is exposed to intense heat and pressure, causing water and minerals trapped within the rock to be released. This lowers the melting point of the surrounding mantle, generating magma.

The newly formed magma is less dense than the surrounding rock and gradually rises through fractures and weaknesses in the Earth's crust. Over time, repeated eruptions build volcanic mountains on the surface. This process has produced numerous volcanic chains throughout the Philippines, particularly along the Luzon Volcanic Arc in the north and the Mindanao Volcanic Arc in the south. Volcanoes are found on many of the country's major islands, making volcanic activity a significant part of the nation's geology and natural history.

Some Philippines volcanos are difficult to spot from space. They are often covered by dense vegetation, which is similar to the vegetation near the volcanoes. In the tropical climate of the Philippines abundant precipitation quickly erode mountain slopes, especially if they’re made of mostly loosely consolidated ash and tephra (volcanic debris). [Source: Erik Klemetti, Wired, June 7, 2016]

Websites and Sources on Volcanoes: USGS Volcanoes volcanoes.usgs.gov ; Volcano World volcano.oregonstate.edu ; Volcanoes.com volcanoes.com ; Wikipedia Volcano article Wikipedia , Smithsonian Global Volcanism Program volcano.si.edu operated by the Smithsonian has descriptions of volcanoes around the globe and a catalog of over 8,000 eruptions in the last 10,000 years.

Volcanic Eruptions in the Philippines

Tectonic framework of the Philippine archipelago; Red lines denote traces of the Philippine fault based on interpretation of aerial photographs whereas purple lines denote those based on interpretation of shaded relief and topographic maps; Red arrow indicates the leftlateral motion on the Philippine fault; Red open stars show large historical earthquakes along the Philippine fault from Bautista and Oike (2000); Black lines with triangles denote subduction boundaries with arrows showing relative motion between the Philippine Sea plate and Sunda (Eurasia) plate from Seno et al; (1993), from Japanese government

Volcanoes in the Philippines are among the deadliest in the world. About 13 percent of recorded eruptions there have caused fatalities, and many victims’ bodies are never found. People who live near dangerous Philippines volcanoes such as Mayon say the warning and evacuation procedures are good but the facilities that take in people after they have been evacuated are poor. While volcanic eruptions present significant hazards, including ashfall, pyroclastic flows, lava flows, and lahars (volcanic mudflows), they also provide important benefits. Over thousands of years, volcanic eruptions have enriched the soil with minerals, creating some of the most fertile agricultural land in the country.

Worst Recorded Volcanic Eruptions (number of dead): 1) Mt, Tambora, Sumbawa, Indonesia, Apr. 10-12, 1815 (92,000); 2) Krakatoa, Indonesia, Aug. 26-28, 1883 (36,000); 3) Mt. Pelée, Martinique, May 8, 1902 (28,000); 4) Nevado del Ruíz, Columbia, Nov. 13, 1985 (23,000); 5) Mt. Vesuvius, Italy, Aug 24, 79 AD (16,000); 6) Mt. Unzen, Japan, May 21, 1792 (14,500); 7) Kelut, Java, Indonesia, 1586 (10,000); 8) Laki, Iceland, June 8, 1783 (9,350); 9) Mt. Kelut, Java, Indonesia, May 19, 1919 (5,000); 10) Mt. Vesuvius, Italy, Dec. 15, 1631 (4,000); 11) Mt. Papandayan, Java, Indonesia, Aug. 12, 1772 (3,000); 12) Mt. Lamington, New Guinea, Jan 17-21, 1951, New Guinea (3,000); 13) El Chichon, Mexico, May 28, 1982 (1,800); 14) Lake Nyos, Cameroon, Aug. 21. 1986 (1,700); 15) Mt. Taal, Philippines, Jan 30. 1911; 16) Santa Maria, Guatemala, Apr. 24, 1902 (1,000); 17) Mt. Pinatubo, Luzon, Philippines, June 15, 1991 (800) ; 18) Mt. St. Helens, May 18, 1980 (57).

The world's dangerous volcanoes (as judged by their potential for a dangerous eruption and nearness to major population areas): 1) Merapi (Indonesia); 2) Taal (Philippines); 3) Unzen (Japan); 4) Sakurajima (Japan); 5) Ulawun (Papua New Guinea); 6) Mauna Loa (the United States); 7) Rainier (the United States); 8) Colima (Mexico); 9) Santa Maria/ Santiaguito (Guatemala); 10) Galeras (Columbia); 11) Teide (Canary Islands); 12) Vesuvius (Italy); 13) Etna (Italy); 14) Santorini (Greece); 15) Niragongo (Zaire). [Source: International Association of Volcanology and Chemistry of the Earth's Interior]

Most Active Volcanoes in the Philippines

Mayon Volcano (Albay Province in the Bicol Region of southeastern Luzon) is the most active volcano in the Philippines and one of the country's most recognizable natural landmarks. It is renowned around the world for its near-perfect symmetrical cone, which has earned it a reputation as one of the most beautiful volcanoes on Earth. Mayon erupts frequently, producing lava flows, ash clouds, pyroclastic flows, and volcanic mudflows known as lahars. Because of its frequent activity, it is closely monitored by scientists and remains both a major tourist attraction and a significant natural hazard.

Taal Volcano eruption on January 12, 2020: After several months of being on Alert level 1, Taal Volcano erupts on January 12, 2020, spewing tons of Pyroclastic materials into the air; locals who lives near Taal Lake and Taal Volcano here are fishing for Tilapia, despite the imminent danger of another explosive eruption from the volcano; It shows that a lot of people's livelihood, especially those who lives near the volcano, depends on resources and tourism brought by Taal Volcano and its surrounding lake; No matter how dangerous a volcano is, Volcanoes have done wonderful things for the Earth like Atmospheric cooling and Fertile lands, therefore it should be protected because a lot of people's lives depends on it

Taal Volcano (Batangas Province south of Manila) is one of the world's most unusual volcanoes. It lies within a large caldera filled by Taal Lake, while the volcano itself contains a crater lake, creating a remarkable lake-within-a-lake system. Despite its relatively low elevation, Taal is considered one of the most dangerous volcanoes in the Philippines because of its proximity to densely populated areas. Its eruptions are often highly explosive, occurring when magma interacts with water in powerful phreatomagmatic events that can produce ashfall over wide areas.

Mount Pinatubo (on the boundaries of Zambales, Tarlac, and Pampanga provinces in Central Luzon) was relatively unknown outside the region before 1991, but its massive eruption that year became one of the largest volcanic events of the twentieth century. The eruption sent enormous quantities of ash and sulfur dioxide into the atmosphere, temporarily lowering global temperatures and affecting weather patterns worldwide. Today, the volcano's summit contains a scenic crater lake, and the surrounding landscape serves as a reminder of the dramatic power of volcanic activity.

Mount Kanlaon (on Negros Island) is the highest mountain in the Visayas and one of the country's most active volcanoes. Rising more than 2,400 meters above sea level, it is a massive stratovolcano featuring numerous craters, vents, and geothermal features. Kanlaon frequently experiences seismic activity, gas emissions, and occasional eruptions, prompting authorities to maintain strict monitoring programs. The volcano is also an important ecological area, surrounded by forests that support a rich variety of plant and animal life.

Mount Bulusan (Sorsogon Province at the southeastern tip of Luzon) is a complex stratovolcano known for its frequent steam-driven, or phreatic, eruptions, which can occur with little warning. These eruptions often produce ash plumes that affect nearby communities and agricultural areas. Although Bulusan's eruptions are generally less dramatic than those of Mayon or Pinatubo, its persistent activity makes it one of the most closely watched volcanoes in the country.

Mount Hibok-Hibok (Camiguin Island off the northern coast of Mindanao,) is a highly active volcano that has played a major role in shaping the island's landscape. The volcano is characterized by lava domes, hot springs, and geothermal activity. Its eruptions during the 1940s and early 1950s caused widespread destruction and loss of life, leading to extensive scientific studies and improvements in volcanic hazard management. Today, Hibok-Hibok remains a prominent feature of Camiguin, attracting hikers and visitors while continuing to be monitored for signs of renewed activity.

Philippines — Home of the World’s Largest Known Caldera

Apolaki Caldera Forbes

The Philippines is home to what scientists believe is the largest known caldera on Earth, a massive underwater volcanic depression called the Apolaki Caldera. The feature was identified by marine geophysicist Jenny Anne Barreto and her colleagues during research on the Philippine Rise, formerly known as Benham Rise, an underwater plateau in the Philippine Sea east of Luzon. A caldera is a large basin-like depression formed when a volcano erupts and then collapses into the emptied magma chamber beneath it. The discovery highlighted the immense volcanic forces that helped shape the geology of the western Pacific region millions of years ago. Philippines is home to what scientists believe is the largest known caldera. [Source: Coconuts Manila, October 22, 2019]

The Apolaki Caldera is extraordinary because of its immense size. Researchers estimated that it measures approximately 150 kilometers (93 miles) in diameter, making it more than twice as large as the famous caldera beneath Yellowstone National Park in the United States, which is about 60 kilometers across. According to scientists, the caldera is so large that it is comparable in scale to giant volcanic structures found on Mars and Venus. Its size suggests that it was created by one of the most powerful volcanic events known in Earth's geological history.

Named after Apolaki, a deity associated with the sun and war in Philippine mythology, the caldera preserves evidence of a complex volcanic past. Researchers identified geological features including a breached rim, terraces within the caldera, and a resurgent dome formed when magma pushed the collapsed floor upward after earlier eruptions. These structures indicate that the volcano experienced multiple phases of activity, including both relatively quiet lava eruptions and highly explosive volcanic events. The findings, published in a study examining the geology of the Philippine Rise, provide important insights into the formation of large igneous provinces and the volcanic evolution of the Philippine Sea Basin.

Bulusan Volcano

Bulusan is one of the most active volcanoes in the Philippines. Luzon's southernmost volcano, it lies in Sorsogon Province at the southeastern tip of Luzon at the southeast end of the Bicol volcanic arc occupying the peninsula of the same name that forms the elongated southeast tip of Luzon island. Mount Bulusan (is a complex stratovolcano known for its frequent steam-driven, or phreatic, eruptions, which can occur with little warning. These eruptions often produce ash plumes that affect nearby communities and agricultural areas.

Bulusan in 2007

Bulusan is 1565 meters (5,134 feet) high. It lies 43 kilometers south of the capital city Sorsogon in Sorsogon province about 240 miles (380 kilometres) southeast of Manila. It is a young andesitic volcano built upon the northeast rim of an older dacitic-to-rhyolitic caldera, the 11-km wide Irosin caldera, which was formed about 35,000-40,000 years ago. [Source: volcanodiscovery.com]

Bulusan is flanked by several other large intracaldera lava domes and cones, including the prominent Mount Jormajan lava dome on the southwest flank and Sharp Peak to the northeast. The summit of Bulusan volcano is unvegetated and contains a 300-meter -wide, 50-meter-deep crater. Three small craters are located on the SE flank. Many moderate explosive eruptions have been recorded at Bulusan since the mid-19th century.

Bulusan Volcano Eruptions

Typical eruption style: Explosive. In historic time, frequent small to moderate phreatic and phreatomagmatic ash eruptions. Mudflows from loose deposits on flank are often generated when heavy rains fall (e.g. during taifuns). Stratovolcano Bulusan volcano eruptions: 2011, Oct 2006-07, Mar-Jun 2006, 1994, 1988, 1983, 1981, 1979, 1978, 1933, 1928, 1918-22, 1916, 1894, 1892, 1889, 1886, 1852(?). [Source: volcanodiscovery.com]

In June 2015, Bulusan had a small phreatic (steam-driven) explosion, its first activity since similar small eruptions in 2011. The eruption itself lasted only 10 minutes, producing a 1-kilometre ash plume which dusted nearby villages. This type of explosion is relatively common at Bulusan and other volcanoes in the Philippines. They are generated by water seeping down into the hot rocks at the summit of the volcano. As the heat from below continues to warm these water-saturated rocks, the water can flash to steam, prompting an explosion that contains no new magma. Meanwhile, Mayon, another restless Philippine volcano, continues to experience earthquakes without erupting. [Source: Wired, June 16, 2015]

In June 2022, Mount Bulusan erupted for 17 minutes, sending a plume of ash at least one kilometre (0.6 miles) into the atmosphere and covering several towns in volcanic dust, according to AFP reports. The eruption was phreatic, meaning the explosion was triggered by heated magma in the volcano's crater coming into contact with water. Such eruptions tend to shoot out steam and ash rather than liquid lava. [Source: Zachary Rosenthal,June 8, 2022]

Bulusan Volcano's monitoring network in 2025

The ashfall that followed covered the municipality of Juban. Juban is located approximately 12 hours' drive southeast of the Philippine capital, Manila. Ash and steam spewed from Mount Bulusan on June 5 as seen from Casiguran in Sorsogon province. Two villages in Juban experienced 'zero visibility' due to the heavy ashfall, prompting the deployment of first responders to the area to clean up the ash and assist those in need. 'Our priority is senior citizens and those with asthma,' said Dennis Despabiladeras, an official from Juban's Disaster Management and Risk Reduction Office, speaking to AFP. Thankfully, no serious injuries have been reported to the authorities following the eruption.

The ash made videos and photos taken in Juban look as if they were in black and white. The only colour visible from above comes from the brightly coloured cars driving through local towns. Authorities in the Philippines have warned of further eruptions from the historically active Mount Bulsan and have raised the alert level to one on the country's five-level system, indicating 'low-level unrest'. Even residents were barred from entering a roughly 2.5-mile radius around the volcano "due to the increased possibilities of sudden and hazardous phreatic eruptions," according to AFP.

Mount Bulusan Eruption In 2011

Mount Bulusan erupted in the morning at 9:15am on February 20, 2011. ABS-CBN News Channel and the Huffington Post reported: “Ash and steam from the explosion reached as high as 2 kilometers. Mount Bulusan had increased volcanic activity in November 2010, spewing ash and steam over several days. Families were evacuated at the time. PHIVOLCS confirmed the ash explosion and says it was caused by steam buildup. The institute advises all aircraft to avoid the vicinity and warns that the ash emission could trigger respiratory illnesses for those near the volcano. People are advised not to enter the 4-kilometer danger zone around Mount Bulusan.[Source: Huffington Post, February 20, 2011]

According to the Daily Mail: “Hundreds of people fled homes and farms in central Philippines after a volcano spewed a 2km-high column of ash covering several villages, officials said. Soldiers were patrolling a 4km danger zone around the crater of Mount Bulusan, one of the most active volcanoes in the poor Southeast Asian nation. Schools were closed and were being used as temporary shelters, Major Harold Cabunoc told reporters. The army sent trucks to move around 2,000 people to safety. 'We're also asking aircraft to avoid the volcano,' Major Cabunoc said. [Source: Daily Mail, February 21, 2011]

five volcanoes, including Mt Mayon in southern Luzon

PHIVOLCS said Mount Bulusan started spewing ash in November 2010 but the activity had died down just before the end of 2010. The latest eruption saw a huge plume of grayish smoke sent more than a mile into the blue sky above while ash drifted southwest towards four framing towns in Sorsogon province.

About 1,200 villagers in the province were forced to flee to emergency shelters and relatives' homes, according to Benito Ramos of the government's disaster-response agency. Army trucks helped villagers move from communities hit by the ashfall and emergency teams handed out protective masks, Ramos said. There have not been any government orders to evacuate communities near the mountain. While many scrambled to safety, residents streamed out of houses in Irosin town to gaze or take pictures of the mid-morning spectacle using their cellphones. Still-hot debris at the peak of Bulusan came into contact with water, sparking the explosion. Such steam-driven blasts have happened since November and could continue in coming weeks, Solidum said.

Bulusan Spews Ash

In March 2006, Bulusan erupted in February 2006 after being quiet for 11 years, spewing ash clouds as high as 1.5 kilometers into the sky and prompting government warnings to residents not to go near the volcano. PHIVOLCS reported a steam-driven explosion from the summit of the 1,559-meter volcano at 10:58 p.m. It lasted 20 minutes and was accompanied by an earthquake. [Source: Bobby Labalan, Blanche S. Rivera, PDI Southern Luzon Bureau Inquirer, March 23, 2006 ||||]

Bobby Labalan and Blanche S. Rivera wrote in the Southern Luzon Bureau Inquirer, “Resident volcanologist Bella Tubianosa said that because of the westward direction of winds, only the villages of Cogon, Tinampo, Gulang and Bolos in Irosin town and the villages of Bacolod, Sapa, Sangkayon and Biriran in Juban town were covered by the ash fall. An earthquake was accompanied the explosion at 10:58 p.m., but three more earthquakes followed at 11:30 p.m., 11:32 p.m. and 11:37 p.m.||||

"Technically, it's an eruption, although it's only an ash explosion since the materials spewed were mostly ash and not pyroclastic ones," Ed Laguerta, Mount Mayon resident volcanologist who is based in Legazpi City in Albay, said late yesterday afternoon.Laguerta, who went to Bulusan to assist in monitoring activities, said there was not much hazard or threat to life at present but only inconvenience to local residents, except for those near the crater. He said no succeeding activity had yet taken place after Tuesday's ash explosion. ||||

“Bulusan usually exhibits a "one-shot deal" — meaning, once it explodes, it will take days before another activity occurs, he said. Laguerta noted the reactivation of certain fissures down the slopes, as manifested by smoke emissions. Tubianosa said the ash ejection was preceded by at least 63 volcanic quakes and a loud rumbling. PHIVOLCS warned people to stay away from areas within 4 kilometers of the crater that has been designated as a permanent danger zone (PDZ). The zone, which covers portions of Juban, Barcelona, Bulusan and Irosin towns, is off-limits to the public because this will be affected by sudden explosions. Nearby communities near the zone have been warned against more ash explosions that could generate life-threatening volcanic flows. ||||

“At 6 a.m. yesterday, the PHIVOLCS' seismic network around Bulusan recorded 18 low-frequency volcanic earthquakes, 41 high-frequency ones, and four explosion-type earthquakes. High-frequency earthquakes are caused by the breaking of rocks. Low-frequency earthquakes are those caused by the movement of fluid or gas. "What we are warning against are the more dangerous kinds of explosion," PHIVOLCSDirector Renato Solidum said. Hazardous eruption is characterized by tall eruption columns, pyroclastic flows moving down the slope, and lava flows. ||||

“Two days before the eruption, PHIVOLCS raised the Alert Level 1 in Bulusan after recording 73 high-frequency volcanic earthquakes, much higher than the usual five volcanic quakes in 24 hours. The next day, its seismic network recorded 58 volcanic earthquakes, compelling the agency to issue a warning on a possible explosion, which occurred at night. "These are phreatic explosions, which are a precursor to an eruption ... These indicate volcanic unrest," PHIVOLCS volcanology officer-in-charge Jaime Sincioco said in a phone interview. Sincioco said his office was treating the explosion as phreatic. This type of explosion occurs when water impounded in the crater flows into the cracks and meets the hot rocks, converting it to steam. ||||

“Gov. Raul Lee of Sorsogon immediately called the Provincial Disaster Coordinating Council to a meeting to assess the situation and prepare for any eventualities. Lee asked the Department of Education to make available its classrooms in the affected areas and even in towns that might be hit by ash fall for possible evacuation. He mobilized the Philippine Army, Philippine National Police and the Bureau of Fire Protection to clean up the national highway. Before the ash explosion, Bulusan's last activities were recorded from Nov. 27, 1994 to January 1995. It only caused ash fall in villages in Bulusan, Barcelona, Casiguran, Juban, Irosin and Gubat towns and was accompanied by at least 14 minutes of weak tremor.”

One Person Dies of an Asthma Attack as Mount Bulusan Spews Ash in 2006

At least one villager died of an asthma attack near Mount Bulusan as the volcano spewed ash. ABS-CBN: reported: “Officials warned residents to stay away from the mountain after its crater belched ash clouds nearly 2 kilometres (1,2 mile) high, prompting authorities to raise the alert level to two from the one it was ordered in March when ash first began flowing from its crater. At level 3 an explosion is considered possible, at level 4 it is seen as likely and at level 5, the highest alert, an eruption has occurred with lava flows or ash columns reaching 6 km. [Source: ABS-CBN, June 9, 2006 |=|]

“PHIVOLCS told Reuters they were monitoring an increasing frequency of ash explosions and had warned residents in Sorsogon province not to venture within a 4-kilometres (2.5 mile) zone of the 1,559-metre (5,1000 foot) volcano because of fears of sudden explosions. Local communities complained the downpour of volcanic ash had affected their health. "We get very scared when we see the sky dark and when the ash is falling. We are scared," said a villager. Local residents cleaned their yards and reached for the garden hose to wash away greyish ash from plants and roofs of their homes. Bulusan, one of the six most active volcanoes in the Philippines, has had five ash eruptions since March. |=|

“Experts warn they cannot predict when or even if the volcano will erupt. "We can't say what date or what day it will explode," said Crispolo Diolata Junior, the Officer-in-Charge of the Bulusan branch of PHIVOLCS. In a nearby village, thousands of face masks were distributed to farming villages after volcanic ash fell on homes in the coastal community's 25 villages. The Office of Civil Defence urged residents not to drink ground water because of possible contamination. Local authorities said they were preparing for the worst following the warnings issued by PHIVOLCS. Ash fall was also reported in nearby Juban town and officials said as many as 50,000 people would be evacuated in case of a major volcanic eruption. The Philippines, like neighbouring Indonesia, lies in an area of the Pacific basin that is vulnerable to earthquakes and volcanic eruptions. |=|

Mount Hibok-Hibok

Mount Hibok-Hibok (also known as Catarman Volcano) a stratovolcano and dome complex on Camiguin Island off the north coast of Mindanao. The volcano is 1,332 meters (4,370 feet) high and has a base diameter of 10 kilometers (6.2 miles). It was described in a 1905 report as having "suddenly risen from the plain a short distance from the town of Catarman in 1872". Mount Timpoong and Hibok-Hibok form the two major landmarks within the Timpoong and Hibok-Hibok Natural Monument. The natural monument became an ASEAN Heritage Park in 2015. The indigenous Kamigin Manobo are believed to be the original inhabitants of Mount Hibok-Hibok.[Source: Wikipedia]

Mount Hibok-Hibok’s adjacent volcanic edifices include A) 580-meter (1,900 foot)-high Mount Vulcan, northwest of Hibok-Hibok; B) 1,552 meter (5,092 foot) -high Mount Mambajao, at the center of Camiguin; C) 581 meter (1,906 foot) -high Mount Guinsiliban, southernmost Camiguin; D) 679 meter (2,228 foot)-high Mount Butay; and E) Mount Uhay, north of Mount Guinsiliban.

There are also domes and cones at Campana Hill, Minokol Hill, Tres Marias Hill, Mount Carling, Mount Tibane, and Piyakong Hill. Hibok-Hibok and Mt Vulcan, a volcanic cone created in a 1871 flank eruption, have six hot springs (Ardent Spring, Tangob, Bugong, Tagdo, Naasag and Kiyab), three craters (Kanangkaan Crater, site of a 1948 eruption; Itum Crater, site of an eruption in 1949, and Ilihan Crater, site of a 1950 eruption).

Mount Hibok-Hibok Eruptions

Hibok-Hibok has erupted four times in modern history. The first recorded eruption occurred in 1827, followed by similar activity in 1862. Volcanic activity is currently monitored through solar-powered autonomous stations operated by the Hibok-Hibok Volcano Observatory under PHIVOLCS.[Source: Wikipedia]

From 1871 to 1875, earthquakes and subterranean rumblings were felt on the island. These increased in severity until, on 30 April, a volcanic fissure opened up 400 yards southwest of the village of Catarman, on the northwest flank of the volcano. Lava was continuously ejected from the opening and poured into the sea for four years, destroying the town. At the same time, the vent built a cone which is now known as Mt. Vulcan. In 1875, the Challenger expedition visited the area and described the mountain as a dome about 590 metres (1,950 feet) high with no crater, but still smoking and incandescent at the top.

The portion of the town containing a cemetery subsided into the sea and is now marked by a huge white cross off the coast. The settlement was relocated to the site of the present-day Catarman town centre. The remains of the old town, including the ruins of an ancient Spanish church, convent, and bell tower, are now known as Gui-ob.

From 1897 to 1902, Mt. Hibok-Hibok emitted white, sulfurous steam, damaging villages on the island. Solfataric activity continued until 1902. The volcano disappeared in 1901.

1951 Eruption of Mount Hibok-Hibok

The most devastating volcanic disaster in the history of Camiguin Island occurred on December 4, 1951, when Mount Hibok-Hibok unleashed a catastrophic eruption that transformed the island and claimed hundreds, possibly thousands, of lives. The eruption was the culmination of several years of volcanic unrest that had begun in 1948. During that period, the volcano frequently rumbled, emitted steam and smoke, and generated earthquakes and landslides that alarmed local residents. New lava domes formed near the summit, while smaller eruptions from the Kanangkaan and Itum craters signaled that magma was steadily rising beneath the volcano. [Source: Wikipedia, Chatgpt]

The eruption sequence from 1948 to 1951 followed a pattern later studied by volcanologists. Initial activity involved steam emissions and rock avalanches from the crater area, followed by increasingly powerful explosions that released ash, steam, and volcanic debris. A 1948 Peléan eruption from Kanangkaan Crater caused relatively limited damage, but activity intensified the following year when eruptions from Itum Crater triggered landslides that killed 79 people. Despite these warnings, many residents remained on the island, relying on fertile volcanic soils for farming and hoping that the volcano would quiet down.

Shortly before dawn on December 4, 1951, Hibok-Hibok erupted with tremendous force. Boiling lava, incandescent rocks, ash, and superheated clouds of gas swept down the slopes in fast-moving pyroclastic flows known as nuees ardentes, or glowing avalanches. These deadly currents raced through villages with little warning, burning or suffocating people in their path. Entire communities were overwhelmed as houses collapsed, vegetation was scorched, and thick deposits of volcanic debris buried roads and farmland. Survivors later described hearing a deafening roar from the mountain before darkness and choking ash engulfed the landscape.

The eruption devastated nearly 19 square kilometers (7.3 square miles) of land, particularly around the municipality of Mambajao. Poisonous gases and volcanic debris destroyed homes, crops, and infrastructure, leaving large areas uninhabitable. Estimates of the death toll vary considerably, ranging from about 500 to more than 3,000 people. The exact number has never been determined because many victims were buried beneath volcanic deposits or never officially accounted for in the chaos that followed. It remains one of the deadliest volcanic eruptions in Philippine history and led to the creation of PHIVOLCS.

Eyewitnesses reported scenes of panic as residents fled toward the coast seeking safety. Some escaped by boat to neighboring islands, while others attempted to outrun the advancing pyroclastic flows. Survivors recalled villages disappearing beneath clouds of ash and fire, with visibility reduced to near zero. Families were separated in the confusion, and many people escaped with only the clothes they were wearing. Those who survived often faced shortages of food, shelter, and clean water in the days that followed.

The disaster dramatically altered the island's population and economy. Before the eruption, Camiguin's population had reached approximately 69,000 people. In the aftermath, widespread destruction and fear of future eruptions prompted a mass exodus, reducing the population to about 34,000. Thousands of residents relocated permanently to Mindanao and other parts of the Philippines, reshaping the island's demographic and social landscape for decades.

Scientists later analyzed the 1948–1952 eruption cycle and identified four general phases of activity. These began with steam emissions and rockfalls, followed by explosive eruptions that produced ash clouds and pyroclastic flows. The third phase involved the eruption of glowing volcanic materials, heavy ashfall, lava flows, and occasional crater outbursts. Finally, activity gradually declined as emissions of steam and volcanic debris decreased. This eruption sequence became an important case study in Philippine volcanology and helped scientists better understand the behavior of dome-building volcanoes.

Sardine Boy and the Deadly Volcanic Eruption on Mount Hibok-Hibok

The 1951eruption of Mount Hibok-Hibok destroyed the home of Benito Aclo while he was away running an errand. Remarkably, his story, commonly referred to “Sardine Boy,” did not end in tragedy. Aclo now lives on the slopes of the same volcano that destroyed his village and killed his family.

On a December morning in 1951, when he was just twelve years old, Aclo had left his home before sunrise to run an errand. “I was the middle child and was often sent to fetch things,” he recalled. “That day my mother sent me down the mountain to buy tinned fish.” As dawn broke, the ground began to shake. Without warning, the volcano erupted violently, sending ash and molten rock down the mountain. A river of lava swept through Ilihan, destroying everything in its path and killing everyone there—including Aclo’s family. “There was a lot of noise and smoke,” he said quietly. “I wanted to go back up the mountain. I thought I could save them.” Instead, he was evacuated to nearby Davao City.

Aclo was the only survivor from his village. Because he survived while away buying canned fish, people began calling him “Sardine Boy.” His life was spared by a simple errand. When I asked how often he thinks about the family he lost, his eyes filled with tears. “Every day,” he said. “But especially on All Souls’ Day when people visit their dead. I have no family in the graveyard.”

On the way down from the mountain, I passed through the crater where Ilihan once stood. Instead of a barren, burned landscape, the area was full of life. Frogs croaked, birds chirped, bees buzzed, and the air smelled of thick jungle vegetation. Like the island itself, Aclo’s story eventually turned toward life and renewal. Several years after the eruption, he returned to Camiguin. There he met his wife Gloria, and together they raised seven children. They were married for more than sixty years until her death recently. Aclo keeps her photograph beside his chair. Other photos around the room show their wedding, their children, and their grandchildren.

Image Sources: Wikimedia Commons

Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, Lonely Planet Guides, Library of Congress, Philippines Department of Tourism, Compton’s Encyclopedia, The Guardian, National Geographic, Smithsonian magazine, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Wall Street Journal, The Atlantic Monthly, The Economist, Foreign Policy, Wikipedia, BBC, CNN, and various books, websites and other publications.

Last updated May 2026