Phivolcs: Seismic events continue in Taal Volcano

Volcanic tremors continued to be recorded in Taal Volcano in Batangas province, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported on Monday morning, August 11, 2025. (Photo courtesy of Jillian Dumas.)

LUCENA CITY—Volcanic tremors continued to be recorded in Taal Volcano in Batangas, the Philippine Institute of Volcanology and Seismology (Phivolcs) said on Monday morning.

READ: Phivolcs warns of possible minor eruption in Taal volcano due to increased seismic activities

In its bulletin, Phivolcs said that state volcanologists detected five tremors over the past 24 hours, which lasted a total of seven hours and 30 minutes.

On Sunday, the agency logged 19 volcanic earthquakes and 17 volcanic tremors. From Aug. 1 to Aug. 9, Taal Volcano recorded only four earthquakes and one tremor, based on Phivolcs data.

In its latest update, Phivolcs also noted the “moderate emission” of 374 metric tons (MT) of sulfur dioxide (SO₂) from Taal’s main crater, which rose to 900 meters high.

In an advisory issued on Sunday, Phivolcs said stations of the Taal Volcano Network (TVN) recorded an increase in real-time seismic energy measurement (RSAM) along with continuous volcanic tremor since Sunday morning.

The agency also observed a “moderate to voluminous plume” from the volcano’s main crater at the onset of the RSAM increase. It added that Taal has been releasing low levels of sulfur dioxide since June, with an average of 412 MT measured last Friday.

“This sharp increase in RSAM and vigorous steaming from the main crater may lead to a phreatic or even a minor phreatomagmatic eruption,” Phivolcs warned.

Phreatic eruptions are steam-driven explosions that occur when water beneath the ground or on the surface is heated by magma, lava, hot rocks, or new volcanic deposits, such as tephra and pyroclastic-flow deposits.

Taal had a phreatic eruption that lasted 17 minutes on June 17.

Phivolcs reminded the public that Alert Level 1 remains in effect over Taal Volcano, “which means that it is still in abnormal condition and should not be interpreted to have ceased unrest nor ceased the threat of eruptive activity.”

“At Alert Level 1, sudden steam-driven or phreatic or minor phreatomagmatic eruptions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas can occur and threaten areas within TVI (Taal Volcano Island),” Phivolcs said.

The agency reiterated that entry to Taal Volcano Island, boating activities on Taal Lake, and flying aircraft near the volcano remain strictly prohibited./coa