Short phreatomagmatic bursts and volcanic earthquakes have occurred at Taal Volcano in the past 24 hours, the Philippine Institute of Volcanology and Seismology (Phivolcs) said in its volcano bulletin on Tuesday, Nov. 23.
"Three short-lived phreatomagmatic bursts were recorded at 8:11 a.m., 8:17 p.m. and 8:34 p.m. yesterday (Nov. 22), that lasted one to five minutes based on the seismic record. These events produced plumes 200 to 1,500 meters tall that drifted southwest," Phivolcs said.
Phreatomagmatic burst occurs when hot magma comes into contact with groundwater.
In the past 24 hours, Phivolcs also recorded 30 volcanic earthquakes, including 23 volcanic tremor events having durations of two to five minutes, four low-frequency volcanic earthquakes, and three hybrid volcanic earthquakes and low-level background tremor that has persisted since July 7.
It said that the activity at the main crater was still dominated by the upwelling of hot volcanic fluids in its lake which generated plumes 2,100 meters tall.
Based on its latest measurement, sulfur dioxide (SO2) emission averaged 6,643 tons per day on Nov. 22. Its highest recorded SO2 emission was at 25,456 tons per day on Oct. 5.
Phivolcs reminded the public that Taal Volcano remains under alert level 2, which means that the volcano continues to manifest "increased unrest."
The volcano has been under alert level 2 since July 23, 2021.
"Sudden steam- or gas-driven explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas can occur and threaten areas within and around TVI," Phivolcs warned.
It also reiterated that entry into the Taal Volcano Island, which is a permanent danger zone, especially the vicinities of the main crater and the Daang Kastila fissure, and extended stay on Taal Lake must be strictly prohibited.
Phivolcs advised local government officials to continuously assess and strengthen the preparedness of previously evacuated barangays around Taal Lake in case of renewed unrest.