MANILA, Philippines — Taal Volcano eruption has eased up in the past 24 hours, but the Philippine Institute of Volcanology and Seismology (Phivolcs) said this does not mean that the worst is over.
“Kapag sinabi mong humihina, trending, ibig sabihin from malakas, pababa. Ang sinasabi namin, generally mas mahina kesa sa nakaraang araw (When you say it’s decreasing, that it’s trending, from strong to weak eruption. What we’re saying is generally, it’s weaker compared to yesterday),” Department of Science and Technology (DOST) Undersecretary Renato Solidum Jr. said in a press briefing Wednesday morning.
“Iba yung talagang definite ka na pag humihina eh, parang may tinutukoy ka na pawala na. Mahirap sabihin yun (It’s different when you’re definite that it’s weakening. It’s like you’re saying that it’s diminishing. That’s hard to tell),” he clarified.
Solidum said this behavior of the volcano is normal because it cannot sustain strong eruptions due to magma supply.
“Normal yan sa eruption. Kung mabagal ang pag-akyat ng magma, konti lang ang isasaboy niya. Pero kung mabilis ang pagakyat ng magma, dun ka makakakita ng mas delikadong pagsabog (That’s normal in eruptions. When the rise of magma is slow, it will only release a few. But if the magma rises quickly, we’ll see a more destructive eruption),” he said.
Cracks and quakes
The ongoing eruption generated plumes as high as one kilometer and spewed ash to the southwest of the main crater.
New fissures or cracks indicating high volume of magma were also observed in several areas in Batangas.
These are Sinisian, Mahabang Dahilig, Dayapan, Palanas, Sangalang, Poblacion, and Mataas na Bayan in Lemery; Pansipit and Bilibinwang in Agoncillo; Poblacion 1, 2, 3, and 5 in Talisay; Poblacion in San Nicolas; and across the road connecting Agoncillo to Laurel.
“Kapag itong main crater ang pumuputok, nagkakaroon tayo ng pagbitak, at yung pagbitak ay manifestation ng ground deformation o yung pag-alsa ng bulkan, kasama na yung lawa at paligid ng lawa (Whenever the main crater erupts, there will be fissures, and these fissures are manifestations of ground deformation or the rise of the volcano, together with the lake and its surroundings),” said Ma. Antonia Bornas, chief of Phivolcs’ Volcano Monitoring and Eruption Prediction Division.
Phivolcs said that the locations of the fissures covering Lemery, Volcano Island, Talisay and Tanauan are the same ones recorded during the 1911 eruption.
In addition, Phivolcs recorded 159 volcanic earthquakes from 5 a. m. Tuesday until 5 a. m. Wednesday. 28 of these were felt with intensities ranging from Intensity I to III.
“Iba yung nangyayari dun sa ibabaw na nakikita natin yung patuloy na pagsabog, iba rin yung nangyayari na indikasyon ng nanggagaling sa ilalim na sa tingin namin patuloy yung pagakyat ng magma. At habang umaakyat ay nagpoproduce ng earthquake kasi napapagalaw yung mga bitak o fissures na marami dito ay naiproduce nung 1911 (What happens on the surface where we see the continuous eruption is different from what’s happening below, which we believe is an indication of magma rising to the surface. And as it does, earthquakes are produced because of the movement of the cracks or fissures, most of which were produced in 1911),” Solidum said.
Toxic volcanic gas
Phivolcs also reported lower sulfur dioxide emission on Tuesday at an average of 1686 tonnes per day. On Monday, it was at around 5000 tonnes.
Sulfur dioxide is contained in magma and usually separates from it once the magma reaches the surface. However, the lower amount of sulfur dioxide does not mean that there is no more magmatic activity.
“Hindi nangangahulugan na nawalan tayo ng magma. Nandyan pa yan. Hindi pa umaakyat yung iba (It doesn’t mean there’s no more magma. It’s still there. The rest haven’t risen yet),” warned Bornas.
On Tuesday, Phivolcs said that the continuous volcanic earthquakes, in conjunction with the fissures, indicate further magmatic intrusion beneath the Volcano, hinting an impending explosive eruption.
Because of this, Phivolcs renewed their call for total evacuation of the Volcano Island and high-risk areas within the 14-kilometer radius danger zone.
Since Sunday evening, the Taal Volcano has been at Alert Level 4 for “imminent hazardous eruption.”