MANILA, PHILIPPINES – The Philippine Institute of Volcanology and Seismology (Phivolcs) raised the alert level No.1 yesterday to the places near Mount Kanlaon in Negros Oriental after becoming active and having steam explosions on Monday night.
The explosion occurred at 9:55 p.m last Monday and lasted for 8 minutes, and followed by a 1 to 1.5-kilometer high white plume above the volcano’s summit before drifting to southwest.
According to the record provided by the Kanlaon Volcano seismic network, the event “as an explosion signal beginning at 9:30 p.m. and lasted for 30 minutes.”
Rumbling sound was heard in Sitio Mananawin and Sitio Upper Pantao, Barangay Pula in Canlaon City, Negros Oriental.
Four volcanic earthquakes had been recorded by Phivolcs a week prior to the explosion, and the seismic network recorded volcanic tremors that lasted for five hours.
A continuous steam emission with minor ash from the summit crater was observed by the Phivolcs yesterday morning.
Phivolcs raised Mt. Kanlaon’s alert level status from 0 to 1 due to the volcano’s increasing activity which is “at an abnormal condition and has entered a period of unrest.”
Phivolcs advised the local government units and the public to avoid entering the four-kilometer permanent danger zone for possible sudden steam or phreatic eruptions.
Civil aviation authorities were advised to warn pilots flying close to the volcano’s summit crater “ejecta” due to hazardous sudden phreatic eruption which is dangerous for aircrafts.
The Civil Aviation Authority of the Philippines (CAAP) issued a notice to airmen yesterday morning, advising them not to fly near Mt. Kanlaon.
As advised by CAAP spokesman Eric Apolonio, all aircrafts were advised not to fly to the summit or near the volcano starting 11:29 a.m. of Nov. 24 until 1 p.m. of Nov. 25.
A series of ash explosions occurred from March 7 to July 23, 2003, and yet the Mt. Kanlaon has no record of major eruption yet.
According to the record provided by Phivolcs, most of Mt. Kanlaon’s of steam-driven or phreatic activity are clusters of minor outburst in the form of varying intensities and duration.
In 1902, the activity of Mt. Kanlaon is a description of lava flow effusion was reported, Kanlaon’s recent historical activities were mostly mild to moderate ash ejections that generated column heights between 0.5-3 kilometers.
The short ash explosions were accompanied by loud rumbling sound and explosion type earthquakes that sometimes occur and it was recorded by a seismograph located at the slope of the volcano.
Minimal ashfall (with 3mm maximum thickness) had been experienced within 6kms around the volcano’s summit area.
Ash columns had been reported to reach more than 4 kms high in 1969, 1986, and 1996 volcanic eruptions.