KANLAON VOLCANO. This file photo, taken on January 13, 2016, shows houses and rice fields near the foot of Kanlaon Volcano in La Carlota City, Negros Occidental. Photo by Archie Rey Alipalo/AFP
MANILA, Philippines – A total of 136 earthquakes were recorded at Kanlaon Volcano from 8 am on Sunday, June 21, to 8 am on Monday, June 22, or a 24-hour period.
The Philippine Institute of Volcanology and Seismology (Phivolcs) earlier said on Monday that it is closely monitoring the volcano in Negros Island due to an ongoing series of earthquakes.
Phivolcs said in a bulletin released 9:30 am on Monday that 4 of the 136 volcano-tectonic earthquakes observed – at 1:01 am, 1:04 am, 1:34 am, and 2:06 am – were magnitudes 3.2 to 4.7.
The 4 quakes were felt at Intensities II to V in La Carlota City and Bago City, Negros Occidental, and in Canlaon City, Negros Oriental.
Phivolcs also observed "moderate emission of white steam-laden plumes" 200 meters high coming from the volcano's vent.
Last June 13, sulfur dioxide (SO2) emission was measured at an average of 438 tons per day. SO2 is a major gas component of magma.
Phivolcs added that there has been continuing deflation of Kanlaon's lower slopes, but inflation on its mid slopes, since April.
"These parameters indicate that hydrothermal or magmatic activity is occurring beneath the edifice," Phivolcs said.
State volcanologists reminded the public that Kanlaon has been under Alert Level 1 since March 11, which means it is in a period of unrest.
Entry into the 4-kilometer-radius Permanent Danger Zone around the volcano remains prohibited. There could be sudden phreatic or steam-driven eruptions, which may be hazardous.
Based on records posted on Phivolcs' website, Kanlaon's last two phreatic eruptions were in December 2017