Kanlaon Volcano as seen from Canlaon City on Tuesday, April 15.*
The recent ash emissions and minor explosive eruptions at Mt. Kanlaon are all indications that the volcano is preparing for a major eruption, a Philippine Institute of Volcanology and Seismology (Phivolcs) official said on Tuesday, April 15.
There could either be a voluminous lava eruption or a highly explosive worse case eruption, Ma. Antonia V. Bornas, Phivolcs Volcano Monitoring and Eruption Prediction Division chief, told DIGICAST NEGROS.
Kanlaon had three ash emission events, 33 volcanic earthquakes, including 5 volcanic tremors, and emitted 1,850 tons of sulfur dioxide from 12 a.m. Monday to 12 a.m. Tuesday, Phivolcs reported.
Kanlaon spewed ash for more than seven hours on Monday, which resulted in light ash fall in Bago City and La Carlota City, Bornas said.
There was considerable ash fall in the upper slopes of Kanlaon where there are no inhabitants, she said.
The very fine ash is usually suspended in the atmosphere for some time, Bornas said. The wind was strong on Monday so some of the ash probably landed in the sea, she said.
Kanlaon also emitted ash at 12: 28 a.m., 5 a.m. and 3:22 p.m. on Tuesday.
These are part of the developments towards a main eruptive period, Bornas said.
Their geological study based on carbon dating shows that Kanlaon had two major explosive eruptions more than 2,000 and 1,000 years ago, she said.
“But there is no telling when the next big event will happen, we have no blueprint for this, she said.
“This is the first time that we are experiencing this kind of activity from Kanlaon Volcano, this behavior is not in our historical documents,” she said.
They are assessing the situation day by day based on the monitoring parameters and in comparison with volcanoes like Mayon and others worldwide, Bornas said.
She said the unrest at Kanlaon could take a long time before it culminates, so their recommendation is for residents to stay away from the 6-kilometer expanded danger zone.
There are 5,673 displaced Negrenses who have been living in 14 evacuation centers in Negros Occidental for more than four months already.
“Aside from the unrest at the volcano there is restiveness among the evacuees and even a bit of resentment at what is happening to them but again there is a lot of danger from this volcano and it’s very difficult to predict an eruption with sufficient lead time for them to be forewarned and evacuated if they are within six kilometers,” she said.
“The next eruption could be potentially larger with larger hazards that could actually harm them so it is better to stay away from the 6-kilometer danger area,” she said.
On some local officials receiving flak for refusing to allow the evacuees to go home, Bornas said “It’s the duty of local officials to ensure the safety of people, I don’t think any politician would like to inconvenience people unnecessarily”.
“It’s to the credit of politicians who enforce evacuations and other safety measures even though they know that this can politically harm them… Local leaders should be given some credit for making these difficult decisions at this time,” she said.*