MANILA (UPDATE)—Despite weak emissions and fewer tremors, the threat of the Taal Volcano's catastrophic eruption remains high, the state seismology agency said Saturday.
The volcano is still under alert level 4, the second-highest danger level, which means a "hazardous explosive eruption is possible within hours to days," Philippine Institute of Volcanology and Seismology (Phivolcs) director Renato Solidum said.
In the past 24 hours, the volcano's main crater steadily emitted steam and had infrequent weak explosions, he said during a press briefing.
It sent a plume of ash as far as 600 meters in the air while sulfur dioxide emission was measured at 360 tons, he added.
Though the Taal Volcano showed signs of calming down, Solidum said there was still "intense" activity underground as magma continued to move beneath.
"Naiiba ang nakikita natin sa taas at naiiba sa ilalim," he said.
(We are seeing things differently aboveground from what is happening underground.)
Phivolcs maintained that those living within the 14-kilometer radius of the volcano, which sits on an island surrounded by a lake in Batangas province, remains susceptible to base surges in case of a major eruption.
Data from the Philippine Seismic Network showed that some 666 volcanic earthquakes were plotted in the Taal region. Among these, some 174 were felt, ranging from between Magnitude 1.2 and 4.1 and experienced at between Intensity 1 and 4.
Meanwhile, the Taal Volcano Network recorded 876 volcanic earthquakes, including 6 tremors and 20 low-frequency earthquakes.
"Such intense seismic activity likely signifies continuous magmatic intrusion beneath the Taal edifice, which may lead to further eruptive activity," the agency added.
The National Disaster Risk Reduction and Management Council (NDRRMC) said Saturday that some 16,174 families or 70,413 people were still living in 300 evacuation centers.
Some 14 towns in Batangas province have been placed on lockdown to prevent residents from returning to their homes amid Taal Volcano's continued unrest.
A state of calamity were declared in the provinces of Batangas and Cavite while damage to agriculture in the region was pegged at P3 billion.
The volcano, famous for its picturesque setting in a lake, erupted on Sunday, belching a massive plume of ash and steam, causing heavy ashfall in nearby areas. The gray shower reached as far as Metro Manila, halting flights at the Manila airport overnight and suspending classes and work.
It is among 24 active volcanoes in the Philippines and has recorded 33 eruptions since 1572. Its worst eruption was in 1911 where some 1,335 people were killed, data from Phivolcs showed.
The Philippines sits on a unique tectonic setting ideal to volcanism and earthquake activity, Phivolcs said.
It is situated at the boundaries of 2 tectonic plates – the Philippine Sea Plate and the Eurasian plate – both of which subduct or dive beneath the archipelago along the deep trenches along its east and west seaboard.