MANILA, Philippines (UPDATED) – Despite fewer emissions seen from the Taal Volcano as of 1 pm on Tuesday, January 14, the frequent volcanic earthquakes coupled with fissures or cracks indicate that a "hazardous" eruption remains possible.
The Philippine Institute of Volcanology and Seismology (Phivolcs) said the surface activity of the Taal Volcano's main crater slightly eased, though there is still "continuous magmatic and hydrovolcanic activity."
"Lava fountains generated 800-meter-tall dark gray steam-laden plumes that drifted to the general southwest," Phivolcs said in a 1 pm update on Tuesday.
Aside from the lava fountains and the ash plumes, fissures or cracks have been spotted on the ground in the province of Batangas, where the volcano is located.
In particular, Phivolcs said fissures were observed in these areas:
"A fissure was also documented across the road connecting Agoncillo to Laurel, Batangas," Phivolcs said.
Maria Antonia Bornas, chief of the Phivolcs Volcano Monitoring and Eruption Prediction Division, explained in a press briefing that fissures indicate magma continues to rise.
"Meron talagang magma na umaakyat pa sa Taal, kaya po nire-reiterate po natin...na kailangan po i-evacuate ang Taal Volcano Island, ang lawa ng Taal, at ang high-risk areas po sa paligid ng bulkan...within 14 kilometers from the main crater," Bornas said.
(Magma continues to rise from Taal, which is why we're reiterating...the need to evacuate the Taal Volcano Island, the Taal Lake, and the high-risk areas surrounding the volcano...within 14 kilometers from the main crater.)
There have also been a total of 335 volcanic earthquakes in the Taal area since 1 pm on Sunday, January 12.
Of these, 49 volcanic earthquakes were recorded from 2 am to 10 am on Tuesday. Of the 49, 7 were felt with intensities ranging from Intensity II to IV.
"The intense seismic activity coupled with fissuring on the caldera region likely signifies continuous magma intrusion beneath the Taal edifice, which may lead to further eruptive activity," Phivolcs said.
The volcano remains under Alert Level 4, which means a "hazardous" eruption is "imminent" or may occur "within days to hours."
"Hindi porque humina ng kaunti ang surface activity sa main crater ay ibig sabihin naibsan po ang panganib, lalo na po ngayon na meron na tayong fissuring," Bornas said.
(Just because the surface activity slightly weakened doesn't mean that the danger is over, especially now that we're experiencing fissuring.)
Phivolcs earlier said "flashes of volcanic lightning" were also observed on Tuesday morning, along with "new vents" from where lava fountains and steam plumes have been spotted.
The ongoing unrest of the Taal Volcano began with a phreatic or steam-driven eruption at 1 pm on Sunday. This progressed to a magmatic eruption as lava fountains emerged in the early hours of Monday, January 13.
The escalation was quick as Alert Levels 2, 3, and 4 were raised in a matter of hours on Sunday. The highest possible alert level is 5, which means a hazardous eruption is already in progress. (READ: TIMELINE: Taal Volcano eruptions since 1572)
Some residents who were evacuated still live in fear, unsure of what will happen to them, their livelihood, and their homes. (READ: 'Lubog na lahat': Calawit residents return to crushed homes)
Classes remain suspended in some areas for Tuesday. (READ: Taal Volcano eruption: What we know about affected towns, cities)
"Civil aviation authorities must advise aircraft to avoid the airspace around Taal Volcano as airborne ash and ballistic fragments from the eruption column pose hazards to aircraft," Phivolcs said. – Rappler.com