Some 69 earthquakes were recorded around Taal Volcano in the last 24 hours while weak steam billowed from its crater, Phivolcs said Wednesday as it urged those living nearby to remain on alert.
The tremor episodes lasted from one to five minutes while the white, steam-laden plumes rose as high as 20 meters from the crater, Phivolcs said in its 8 a.m. bulletin. Take note that not all earthquakes are felt by humans.
Earlier this week, dozens of villagers were evacuated from the volcano island after Phivolcs recorded an increase in earthquakes since Monday.
Taal Volcano remains on Alert Level 1, meaning a major eruption was unlikely. However, on volcano island, there could be "sudden steam-driven or phreatic explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas." Phivolcs said.
People are warned of possible ashfall, and minor earthquakes. Civil aviation authorities must advise pilots to avoid flying close to the volcano as ash and fragments from a sudden explosions could damage aircraft, Phivolcs said.
What are the warning signs in Taal?
Compared to Saturday and Sunday, there have been more frequent earthquakes in the vicinity of Taal Volcano. Around 50 were recorded on Monday alone, said resident vulcanologist Paolo Reniva.
The PH level or acidity of the crater lake also decreased, he said.
What does this mean?
The earthquakes and less acidic lake point to changes inside the volcano. Magma or molten rocks and/or gas could be shifting, he said.
What will this lead to?
This could lead to a steam-driven or phreatic eruption, he said. Though at the current alert, Level 1, an eruption is unlikely, based on Phivolcs warnings.
Will Taal volcano erupt?
Phivolcs can't say for sure. While Level 1 is the lowest (except Alert 0), Reniva said an eruption at Alert Level 1 was still possible. Alert Level 1 has been in place since March 2020.
"Pinapaalalahanan ang taumbayahn na maging handa at maging alerto sa anumang aktibidad ng Taal Volcano," he said.
Will Alert Level 1 be upgraded?
Phivolcs is monitoring activity in the volcano's vicinity to determine if it's warranted, he said.