Manila Bulletin
Philippines
National
Kanlaon Volcano shows increased seismic, ground deformation activities; Alert Level 1 stays
Philippines
National
Kanlaon Volcano shows increased seismic, ground deformation activities; Alert Level 1 stays
Kanlaon Volcano shows increased seismic, ground deformation activities; Alert Level 1 stays
Published May 4, 2023 02:14 pm
The Philippine Institute of Volcanology and Seismology (Phivolcs) observed a significant increase in the number of earthquakes recorded at Kanlaon Volcano in the past 24 hours.
In its advisory issued on Thursday, May 4, Phivolcs said that the monitoring network at Kanlaon Volcano recorded 20 volcanic earthquakes between 10:25 p.m. on May 3, and 4 p.m. on May 4.
"These earthquakes ranged in energy from magnitude 1.2 to magnitude 2.4 and occurred at shallow depths down to six kilometers beneath the summit crater," it added.
Kanlaon Volcano (Manila Bulletin file photo)
Furthermore, since the second week of April, Phivolcs has observed an "episode of pronounced inflation" on the volcano's southeast middle slopes. It noted that volcanic sulfur dioxide (SO2) emission from the summit crater averaged 632 tons per day when it was last measured on May 1, which according to Phivolcs, is "higher than the average emission of 246 tons per day since March 2023." "SO2 concentrations have also been detected for the first time in continuously monitored thermal springs on the northwestern flanks of the volcanic complex," Phivolcs said. "These parameters likely indicate shallow hydrothermal activity driven by degassing of deeper magma, with increased possibilities of phreatic or steam-driven explosions occurring at the summit crater," it pointed out. Phivolcs reminded the public that Kanlaon Volcano remains on Alert Level 1, indicating a “low-level unrest.” If the upward trend in the monitoring parameters continues, Phivolcs said Kanlaon Volcano’s status could be raised to Alert Level 2 to warn the public of increasing unrest. Phivolcs advised the concerned local government units and the public not to enter the four-kilometer radius permanent danger zone due to the increased likelihood of sudden and hazardous phreatic eruptions that could occur without warning. Civil aviation authorities have also been directed to advise pilots to avoid flying near the volcano’s summit because ejecta from any sudden phreatic eruption can be dangerous to aircraft.
Kanlaon Volcano (Manila Bulletin file photo)
Furthermore, since the second week of April, Phivolcs has observed an "episode of pronounced inflation" on the volcano's southeast middle slopes. It noted that volcanic sulfur dioxide (SO2) emission from the summit crater averaged 632 tons per day when it was last measured on May 1, which according to Phivolcs, is "higher than the average emission of 246 tons per day since March 2023." "SO2 concentrations have also been detected for the first time in continuously monitored thermal springs on the northwestern flanks of the volcanic complex," Phivolcs said. "These parameters likely indicate shallow hydrothermal activity driven by degassing of deeper magma, with increased possibilities of phreatic or steam-driven explosions occurring at the summit crater," it pointed out. Phivolcs reminded the public that Kanlaon Volcano remains on Alert Level 1, indicating a “low-level unrest.” If the upward trend in the monitoring parameters continues, Phivolcs said Kanlaon Volcano’s status could be raised to Alert Level 2 to warn the public of increasing unrest. Phivolcs advised the concerned local government units and the public not to enter the four-kilometer radius permanent danger zone due to the increased likelihood of sudden and hazardous phreatic eruptions that could occur without warning. Civil aviation authorities have also been directed to advise pilots to avoid flying near the volcano’s summit because ejecta from any sudden phreatic eruption can be dangerous to aircraft.