KANLAON VOLCANO AND ITS HISTORY OF ERUPTIONS

KANLAON VOLCANO

Kanlaon in 2023

Kanlaon volcano (also spelled Canlaon) on Negros Island is the highest mountain in the Visayas and one of the country's most active volcanoes. It is a large 2435 meter-high (7,989 feet-high) stratovolcano dotted with numerous flank cones and craters, many of which contain lakes. The summit of Kanlaon contains a two-kilometer-wide, elongated caldera with two craters. One is inactive and contains a crater lake. The second crater to the south is smaller, higher and contains the historically active vent, Lugud crater. Lugud crater is 250 meter wide and 150-200 meter deep. The base of Kanlaon measures an area of 30 x 14 kilometers. [Source: volcanodiscovery.com /*]

Kanlaon volcano straddles the provinces of Negros Occidental and Negros Oriental in the central Philippines. and is part of the Negros Volcanic Belt. It is the most active one of the Central Philippines and is located west of Kanlaon about 36 kilometers southeast of Bacolod City and belongs to Kanlaon National Park. Kanlaon features numerous vents, and geothermal features. It frequently generates 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.

Kanlaon's volcanic activity has shaped the landscape of Negros for thousands of years. The mountain is surrounded by fertile agricultural land, forests, and protected natural areas that support diverse wildlife. It is a popular destination for hikers and nature enthusiasts, although access is often restricted during periods of increased volcanic activity. The volcano's location in a densely populated agricultural region means that even relatively small eruptions can affect thousands of people. As a result, it remains one of the country's most carefully watched volcanic systems.

Kanlaonis is closely monitored by he Philippine Institute of Volcanology and Seismology (PHIVOLCS), which regularly tracks seismic activity, gas emissions, ground deformation, and other signs that may indicate rising magma beneath the volcano. Alert levels are used to inform local governments and residents of potential dangers and the need for evacuation. The mountain's history of sudden eruptions has made preparedness an important part of life in surrounding communities.

Mount Kanlaon is a good place to see birds. According to UNESCO: “Located in the central highlands of Negros, this mountain is home to various species of ferns, lichens, and orchids. It is also inhabited by numerous species of tropical birds. Among them are hundred endemic species of bleeding heart pigeons and the nearing to extinction, Negros Fruit Doves. Others are Barblers and Warblers, Doves, Bulbuls, Flycatchers and woodpeckers. [Source: UNESCO]

Kanlaon Eruptions

location of Kanlaon

Kanlaon has a long record of eruptions dating back to the nineteenth century. According to PHIVOLCS, the volcano has erupted more than 40 times since 1866. Most of these eruptions have been relatively small, consisting of steam-driven explosions, ash emissions, and minor explosive events. The eruptions have mostly been small to medium sized phreatic explosions, causing minor ash fall near the volcano. Kanlaon's geologic record of past deposits include a remarkable large debris avalanche, that resulted from flank failure of the volcano and traveled 33 kilometers to the SW.

Kanlaon is capable of producing significant hazards, including ashfall, pyroclastic flows, toxic gas emissions, landslides, and lahars, or volcanic mudflows. Communities living on its slopes must remain alert to changing volcanic conditions, particularly during periods of unrest. One of the most tragic incidents associated with Kanlaon occurred in 1996. On September 10 of that year, a sudden ash eruption caught a group of hikers near the summit. Three climbers were killed and several others were injured when rocks and volcanic debris were ejected from the crater without warning. The incident highlighted the dangers posed by even seemingly quiet volcanoes and led to stricter regulations governing access to the summit area.

Throughout the twentieth and early twenty-first centuries, Kanlaon experienced numerous episodes of volcanic unrest, including ash eruptions, increased seismic activity, and periods of elevated sulfur dioxide emissions. These events often prompted authorities to establish exclusion zones around the crater and issue warnings to nearby residents. While most eruptions were moderate in scale, they regularly disrupted agriculture and transportation in surrounding areas.

In September 2024, several months before a major eruption, Kanlaon released thousands of tons of volcanic gases in a single day. The emissions prompted the evacuation of hundreds of residents living near the volcano and raised concerns about possible magma movement beneath the mountain. Scientists continued to monitor the volcano closely as seismic activity and gas emissions remained elevated.

Kanlaon volcano eruptions: 2006, 2005, 2003, 2002, 1996, 1993, 1992, 1989, 1988, 1987, 1986, 1985, 1980, 1978, 1970, 1969, 1932-33, 1927, 1905-06, 1904, 1902, 1894, 1893, 1884, 1883, 1866. [Source: volcanodiscovery.com /*]

Kanlaon Volcano Eruptions in the 2000s

2006 ash eruptions A series of new eruptions at Kanlaon volcano began on 3 June 2006. Until 25 July, a total of 23 ash eruptions were reported. All eruptions were phreatic (i.e. no fresh magma was ejected), and ejected ash and steam up to 2 kilometers above the crater. No significant seismic activity had occurred before or after the ash emissions, indicating the explosions were near surface hydrothermal events. [Sources: volcanodiscovery.com, Philippine Institute of Volcanology and Seismology (PHIVOLCS), GVP monthly activity report for Kanlaon ++]

2005 ash eruptions: A brief phreatic ash eruption occurred at Kanlaon volcano on 21 January 2005, producing a 500 m high ash plume. A fine layer of ash fell on the town of Cabagnaan 5.5 kilometers SW of the crater. Ash emissions began again on 20 March and caused minor ash fall in the town of Guintubdan 5 kilometers W of the volcano. Until 4 April, occasional ash eruptions reached 1 kilometers above the volcano, and small ash fall was reported in the towns of La Castellana (16 kilometers SW of the crater), Upper Sag-ang, Yubo (5-6 kilometers SW), and Guintubdan (5-6 kilometers WNW). Ash eruptions stopped after 25 May 2005. ++

2003 small ash eruptions: On 17 March 2003, a gray volcanic plume was observed above Canloaon volcano. Small eruptions produced plumes of steam and ahs rising 100 m above the active crater during the beginning of June. On 8 June, ashfall was observed at Kanlaon City. A total of 46 minor ash ejections were recorded, mostly in June and July. After 23 July, only weak steam emission was noted and seismic activity returned to normal low levels. 2002 ash eruptions: An increase in seismicity during February-April 2002 was followed by a raised alert, increased steaming, and a small ash eruption on 28 November 2002. ++

Kanlaon Volcano Eruptions in the 1980s and 1990s

1996 phreatic eruption with 3 fatalities: A phreatic explosion at Kanlaon volcano on 10 August 1996 killed 3 people who were at the summit when the explosion happened. 18 people were injured by falling blocks and had to be hospitalized. 1993 phreatic eruption: Small phreatic explosions occurred at Kanlaon volcano on 25 August and 3 September 1993. The eruption on 3 September lasted for 8 minutes and produced a steam-and-ash column that rose 1,000 m above the summit before drifting SSW and SSE. Ash fell at the Kanlaon Volcano Observatory 8 kilometers SSE of the summit. The phreatic eruption was accompanied by an earthquake felt at the Cabagnaan Station. ++

1992 eruption: A minor earthquake accompanied an ash eruption at Kanlaon volcano on 10 June 1992. 1989 ash eruptions: Since 25 October 1989 mildly explosive ash ejections occurred almost daily. The eruptions lasted until December 1989. On 3 November, a relatively large eruption produced an ash plume rising 1200 m above the crater. PHILVOLCS scientists had detected ground inflation a few hours before the ash emissions. 1988 eruptions: A series of ash emissions occurred between 21-27 June 1988 and produced plumes of up to 500 m high. Small amounts of ash fell in the village of Mananawin on the SE slope at 980 m elevation. ++

1987 ash eruptions: New euptions started at Kanlaon volcano in April 1987. On the morning of 24 April an eruption produced a fresh ash deposit ~1-2 kilometers wide and 6.5 kilometers long that extended down the SW flank. There was no seismic signal associated with the explosions and no sounds heard by local residents. A sulfur smell was reported from the Cabagnaan Observatory (approximately 6 kilometers SW of the crater) on the same day. The activity was preceded by an increase in sulphate concentrations at Mambucal Aquapool, Mudpool, and Sulfur Spring, 9.75 kilometers NNW of Kanlaon's summit.

1986 powerful eruption of 21 June: Without any preceding seismic activity, Kanlaon had a small eruption on 3 June 1986, producing a plume of 300 m above the crater. 19 days later, on 21 June, a powerful explosion occurred sending a mushroom-shaped plume to 4000 m above the crater. The eruption was accompanied by an earthquake felt at up to 8 kilometers from the summit, as well as booming and hissing noises. ++

Kanlaon Eruptions in 2024

Kanlaon erupted several times in 2024. The most significant eruption occurred on the evening of June 3. The eruption lasted approximately six minutes and sent an ash column about five kilometers (three miles) into the atmosphere. PHIVOLCS recorded 43 volcanic earthquakes during the 24-hour period preceding the eruption and raised the volcano's alert level from 1 to 2 on a five-level scale. Hundreds of residents living within a three-kilometer radius of the crater were ordered to evacuate as ashfall and sulfur odors spread across nearby communities. [Source: CBSNews, December 10, 2024; Steven Yablonski, Fox Weather, December 11, 2024; Kathleen Magramo, CNN, June 4, 2024; AFP, June 5, 2024]

The June eruption also caused major disruptions to air travel. More than 60 flights operated by three domestic airlines were canceled, affecting over 5,000 passengers. Ash blanketed villages surrounding the volcano, and authorities warned of the possibility of further eruptions. Although the Bacolod-Silay Airport resumed operations the following day, travelers continued to experience delays and disruptions.

Heavy rainfall after the June eruption triggered lahars, or volcanic mudflows, on the slopes of Kanlaon. On June 5, torrents of mud, ash, rocks, and water flowed through villages such as Biaknabato in Negros Occidental. Roads were buried under knee-deep volcanic debris, and local disaster agencies deployed heavy equipment, including bulldozers and dump trucks, to clear affected areas. Fortunately, no immediate casualties were reported, although officials warned that lahars remained a serious threat during periods of heavy rain.

A much larger eruption occurred on December 9, 2024. The eruption lasted nearly four minutes and generated an ash column approximately 2.5 miles (four kilometers) above the crater. Pyroclastic density currents—fast-moving mixtures of hot ash, volcanic gases, and rock fragments—traveled about two miles (three kilometers) down the volcano's southeastern slope. PHIVOLCS raised the alert level to 3, warning that further explosive eruptions were possible and urging the evacuation of communities within a six-kilometer danger zone.

The December eruption triggered one of the largest volcanic evacuation operations in the Philippines in recent years. Government officials reported that approximately 87,000 residents were affected by evacuation orders. The towns of La Castellana in Negros Occidental and Canlaon City in Negros Oriental were among the most heavily impacted areas. Emergency shelters were prepared, including a stadium capable of accommodating 30,000 people, while authorities deployed water tankers, filtration systems, face masks, and other supplies to support evacuees.

Ashfall from the eruption spread across a wide area, reaching communities far from the volcano and even affecting Antique Province, about 120 miles (190 kilometers) away across the sea. Several domestic flights and one international flight to Singapore were canceled because of volcanic ash hazards. Officials also warned that heavy rainfall could remobilize freshly deposited volcanic material, creating dangerous lahars in rivers and low-lying communities. Despite the scale of the eruption and evacuation efforts, no fatalities were reported from the December event.

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