Kanlaon

Physical features

Kanlaon has a peak elevation of 2,465 m (8,087 ft) at its highest point. Also it's 2435 m (7,989 ft) in some sources, with a base diameter of 30 km (19 mi) and is dotted with pyroclastic cones and craters. Just below and north of the summit is the active Lugud crater. North of Lugud is a 2 by 0.8 km (1.24 by 0.50 mi) caldera, known as Margaja Valley, with a small crater lake.

The volcano has three hot springs on its slopes: Mambucal Hot Springs on the northwest, Bucalan Hot Spring and Bungol Hot Spring. Its adjacent volcanic edifices are Mount Silay and Mount Mandalagan, north of Kanlaon.

Canlaon, the city that has jurisdiction on the Negros Oriental side of the volcano, lies on its lower slope about 8.5 km (5.3 mi) ESE of the summit.

Eruptions

The most active volcano in the central Philippines, Kanlaon has erupted 28 times since 1919. Eruptions are typically phreatic explosions of small-to-moderate size that produce minor ash falls near the volcano. In 1902, the eruption was classified as strombolian, typified by the ejection of incandescent cinder, lapilli and lava bombs.

Volcanic activity at Kanlaon is continuously monitored by the Philippine Institute of Volcanology and Seismology (PHIVOLCS), the government's bureau that monitors the volcano and earthquakes in the country. Kanlaon Volcano Observatory is located at the campus of La Carlota City College in the barangay of Cubay, La Carlota in Negros Occidental province.

1996 Kanlaon Incident

On August 10, 1996, 24 mountain climbers hiked at the volcano when Kanlaon erupted without warning, killing British student Julian Green and Filipinos Jamrain 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.

One of the Belgians, Caroline Verlinde, said she and her group were about to leave a site near the crater rim when suddenly the volcano ejected ash, stone and hot gas. She ran to a tree for cover and saw her friends being hit by falling hot stones. She said their Filipino guide told them the smoke billowing out from the crater "was just hard."

2001

PHIVOLCS noted in a 22 March report that since January 2001 earthquake clusters or occurrences have been recorded by the seismic monitoring network around the volcano. These earthquakes may signify a reactivation of the volcanic system at depth and could be a precursor to more vigorous activity, such as ash explosions. This interpretation is based on similar earthquake clusters manifested prior to the 10 August 1996 phreatic explosion from the active summit crater of the volcano. In view of the possibility of a sudden ash ejection, PHIVOLCS recommends the immediate suspension of all treks to the summit crater until further notice. As an additional precaution, the pre-defined 4-km-radius Permanent Danger Zone (PDZ) should be avoided at all times.

2002

An increase in seismic activity during February to April 2002 was followed by raising alert on the volcano. An ash eruption occurred on November 28, 2002.

2003

On March 17, 2003, a gray plume was observed above Kanlaon Volcano. Small eruptions produced plumes that rose 100 m above the crater of the volcano. A total of 46 minor ash ejections were recorded. After July 23, 2003, only weak emission was noted and seismic activity returned to normal.

2005

A brief phreatic ash eruption occurred at Canlaon 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 km SW of the crater. Ash emissions began again on 20 March and caused minor ash fall in the town of Guintubdan 5 km W of the volcano. Until 4 April, occasional ash eruptions reached 1 km above the volcano, and small ash fall was reported in the towns of La Castellana (16 km SW of the crater), Upper Sag-ang, Yubo (5–6 km SW), and Guintubdan (5–6 km WNW). Ash eruptions stopped after 25 May 2005.

2006

On June 3, 2006, Kanlaon again exhibited restiveness and spewed steam and ash. Alert Level 1 was issued on June 12, 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 km 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, 2008 PHIVOLCS issued an alert stating that the seismic network at Kanlaon Volcano 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 4-kilometre (2.5 mi) Permanent Danger Zone (PDZ) was maintained around the volcano, as sudden explosions may occur without warning, but no eruptions occurred.

2009

In the 8 days from August 23 to September 1, 257 volcanic earthquakes were recorded. Usual seismic activity during quiet periods is 0 to 4 quakes in any 24-hour period. 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, 2015, Kanlaon had two low energy ash eruption. The volcano is still in the state of unrest. The minor ash eruption of the volcano reached as high as 984 ft (300m). On December 27, 2015, an ash eruption occurred at Kanlaon's active crater. The eruption plume reached as high as 3281 ft (1000m). Light ashfall were reported in some barangays near Kanlaon Volcano.

On 2 January, people in Hinigaran got sick. Many suffered from a respiratory illness with cough and flu-like symptoms.

2016

In March 29 at 6:20 pm, Kanlaon erupted for 12 minutes which produced a volcanic plume 1500 meters above the crater and a "booming sound" was heard in some barangays near the volcano. According to the police department of Canlaon City, 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.