Kanlaon, also known as Mount Kanlaon and Kanlaon Volcano (; ; ), is an active andesitic stratovolcano and the highest mountain on the island of Negros in the Philippines, as well as the highest peak in the Visayas, with an elevation of above sea level.https://volcano.si.edu/showreport.cfm?wvar=GVP.WVAR20230426-272020 Global Volcanism Program, 2023. Report on Kanlaon (Philippines) (Sennert, S, ed.). Weekly Volcanic Activity Report, 26 April-2 May 2023. Smithsonian Institution and US Geological Survey. Mount Kanlaon ranks as the 42nd-highest peak of an island in the world.
The volcano straddles the provinces of Negros Occidental and Negros Oriental, approximately southeast of Bacolod, the capital and most populous city of Negros Occidental and the whole island. It is one of the active volcanoes in the Philippines and part of the Pacific Ring of Fire.
Etymology The name "Kanlaon" means "[place] of Laon", a pre-colonial Visayan goddess of creation, agriculture, and justice. The name Laon itself means "the ancient one", from Visayan , meaning "ancient" or "old."
During the late Spanish colonial period of the Philippines, the volcano was briefly renamed as Malaspina by the Spanish, after the Spanish explorer Alejandro Malaspina of the Malaspina Expedition (1789–1794).
Geography and geology Kanlaon has a peak elevation of , although it is reported as in some sources, with a base diameter of , and is dotted with pyroclastic cones and extinct craters extending to the north-northwest. It is part of the Negros volcanic belt resulting from the subduction of Sulu Sea basin lithosphere of the Sunda plate along the Negros Trench and has been an active subduction zone since the Miocene.
Just below and north of the summit is the active Lugud crater. North of Lugud is a crater known as Margaja Valley, with a small, often seasonal crater lake."Kanlaon Volcano Page" . Philippine Institute of Volcanology and Seismology. The volcano is estimated to have an area of .
The area of the volcano is host to two distinct geothermal systems; a long established system which includes the Pataan thermal area, and which is characterized by neutral sodium and potassium chloride and bicarbonate containing waters an immature system, represented by Hagdan spring characterized by acid-sulfate waters. The Mambukal Hot Springs which are at the far north–east, has mixed waters from these two system types. Other hot springs on its slopes are the Bucalan hot spring to the south-west of the summit, and Bungol hot spring.
Its adjacent volcanic edifices are Mount Silay and Mount Mandalagan, north of Kanlaon.
La Carlota, La Castellana, Murcia, and San Carlos share the Negros Occidental side of the volcano, while Canlaon, the component city that has jurisdiction on the Negros Oriental side of the volcano, lies on its lower slope about ESE of the summit.
Volcanic activity The most active volcano in the Visayas, Kanlaon has erupted more than 40 times since 1819. Eruptions are typically phreatic of small-to-moderate size that produce minor ash falls around the volcano. In 1902, the eruption was classified as Strombolian, typified by the ejection of incandescent cinders, lapilli, lava bombs and gas fumes.
Volcanic activity at Kanlaon is continuously monitored by the Philippine Institute of Volcanology and Seismology (PHIVOLCS), the government's bureau that monitors the volcanoes and earthquakes in the nation, although unlike Mayon and Pinatubo, the volcano has never been studied in-depth and its age is not yet accurately calculated. Kanlaon Volcano Observatory is located at the campus of La Carlota City College in Barangay Cubay, La Carlota, Negros Occidental.
1996 On August 10, 24 mountain climbers hiked the volcano when Kanlaon erupted without warning, killing British student Julian Green and Filipinos Noel Tragico and Neil Perez, who were trapped near the summit close to the crater. The local authorities rescued 17 others, including 10 Belgians, another British climber and six Filipinos while Edwin Ematong, a member of the Negros Mountaineering Club Inc. and who, along with his cousin Neil Perez, guided the British Nationals survived the eruption, having descended the volcano ahead of his group.
One of the rescued Belgians, Caroline Verlinde, said she and her group were about to leave a site near the crater rim when suddenly the volcano ejected ash, stones and hot gas. She ran to a tree for cover and saw her friends being hit by falling hot tephra. She said their Filipino guide told them the smoke billowing out from the crater "was just ordinary."
2001 PHIVOLCS noted in a March 22 report that since January, earthquake clusters or occurrences had been recorded by the seismic monitoring network around the volcano. These earthquakes might have signified a reactivation of the volcanic system at depth and could be a precursor to more vigorous activity, such as ash explosions. This interpretation was based on similar earthquake clusters manifested prior to the 1996 phreatic explosion from the active summit crater of the volcano. In view of the possibility of a sudden ash ejection, PHIVOLCS recommended the immediate suspension of all treks to the summit crater until further notice.
2002 An increase in seismic activity during February to April was followed by raising alert on the volcano. An ash eruption occurred on November 28.
2003 On March 17, a gray plume was observed above Kanlaon. Small eruptions produced plumes that rose above the crater of the volcano. A total of 46 minor ash ejections were recorded. After July 23, only weak emission was noted and seismic activity returned to normal.
2005 A brief phreatic ash eruption occurred on January 21, producing a high ash plume. A fine layer of ash fell on Cabagnaan, SW of the crater. Ash emissions began again on March 20 and caused minor ashfall in W of the volcano. Until April 4, occasional ash eruptions reached 1 km above the volcano, and small ash fall was reported in La Castellana ( SW of the crater), Upper Sag-ang, Yubo ( SW), and Guintubdan ( WNW). Ash eruptions stopped after May 25.
2006 On June 3, Kanlaon again exhibited restiveness and spewed steam and ash. Alert Level 1 was issued on June 12. Until July 25, 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 above the crater. No significant seismic activity had occurred before or after the ash emissions, indicating the explosions were near surface hydrothermal events.
2008 On February 10, PHIVOLCS issued an alert stating that the seismic network at Kanlaon recorded a total of 21 low frequency volcanic earthquakes (LFVQ) during the past 24 hours. Due to the increasing number of recorded volcanic earthquakes, PHIVOLCS raised Kanlaon Volcano's alert status from Alert Level 0 to Alert Level 1, which means the volcano is at slightly elevated unrest and volcanic activity could lead to steam and ash ejections. A Permanent Danger Zone (PDZ) was maintained around the volcano, as sudden explosions may occur without warning, but no eruptions occurred.
2009 From August 23 to September 1, 257 volcanic earthquakes were recorded. Epicenters of the recorded quakes were clustered at the north-west slope which may indicate movement of an active local fault at the slope induced by pressure beneath the volcano. Surface observations did not show any significant change in the steam emission from the crater. PHIVOLCS maintained the alert status at Level 0.
2015 On November 23, Kanlaon had a small, steam-driven explosion. PHIVOLCS raised the alert level to 1 (mild restiveness). On December 12, Kanlaon had two low energy ash eruptions. The minor ash eruption of the volcano reached as high as . On December 27, an ash eruption occurred at Kanlaon's active crater. The eruption plume reached as high as . Light ashfall were reported in some barangays near Kanlaon Volcano.
2016 On March 29 at 6:20 pm, Kanlaon erupted for 12 minutes which produced a volcanic plume above the crater and a "booming sound" was heard in some barangays near the volcano. According to the police department of Canlaon, several fire balls, which were coming from the crater of the volcano, started to flow following a booming sound and causing a bush fire. PHIVOLCS issued alert level number 1. No casualties were reported.
2020 On March 11, PHIVOLCS raised the volcano's alert level from 0 to 1 due to its abnormal activities since March 9. 80 volcanic earthquakes were plotted since then. On June 21, the volcano showed some signs of increased unrest. By June 22, the volcano's activity continued, with a series of tectonic earthquakes ranging from M3.2 to M4.7. A total of 278 earthquakes was observed for a 72-hour period (from June 21, 8AM – June 24, 8AM), possibly related to the magmatic activity underneath the volcano. Earthquakes continued, with steam and fumarolic activity rising 200–300 meters above. PHIVOLCS reminded the public to stay away to the 4-km PDZ (Permanent Danger Zone) around the volcano, as abnormal conditions and sudden phreatic explosions might occur.
2024–2026
On June 3, PHIVOLCS raised the alert level of Kanlaon from alert level 1 to alert level 2, indicating increasing unrest after an explosive eruption occurred on its summit vent at 6:51 p.m. PST. The eruption produced a voluminous and incandescent plume that rose above the vent and a probable short pyroclastic density current (PDC) of approximately 2-3 km down the south and southeastern slopes of the volcano. The eruption lasted for six minutes and was followed by a relatively strong volcanic earthquake. Sulfurous odors and ashfall were reported by communities on the western slope of the volcano, particularly in Bago, La Carlota, La Castellana and Canlaon, and as far as Bacolod, away. Particles from the volcano were deposited in the form of haze as far as the Bicol Region. On June 5, rains triggered lahar flows in La Castellana.
Evacuations were ordered in Canlaon for five barangays near the volcano and communities located along rivers flowing from the volcano, as well as in La Carlota and La Castellana. A mask mandate was also imposed in San Carlos. At least 4,752 people were displaced, while offices in Canlaon were ordered closed on June 4. Authorities in Negros Occidental were also placed on heightened alert, with ashfall warnings declared in Canlaon, La Carlota and La Castellana. At least 29 flights at Ninoy Aquino International Airport as well as in Iloilo, Cebu, Kalibo, Bacolod, Davao, Cagayan de Oro, General Santos and San Jose Airports were cancelled due to the eruption. On June 4, several flights were cancelled and a mandatory emergency evacuation within a 3-kilometer radius was ordered. Canlaon Mayor Jose Chubasco Cardenas said that 23,622 residents of five barangays were affected. A state of calamity was declared in Canlaon and La Castellana. Around 23,000 hectares of sugarcane fields in Negros Island were affected by the eruption, while a curfew and water rationing was imposed in La Carlota and La Castellana due to sulfur contamination in regular sources. Damages in agriculture were estimated at ₱104.8 million, while 3,890.5 metric tons of crops were lost and at least 3,421 animals and livestock died.
On July 15, PHIVOLCS issued a notice regarding the increasing swelling of Kanlaon's edifice, which has been persisting since mid-June. PHIVOLCS noted that this ongoing ground deformation could indicate magmatic intrusion, potentially increasing the likelihood of eruptive activity.