The Philippine Institute of Volcanology and Seismology on Sunday, July 3, issued a notice of an increase in activity at Kanlaon Volcano in Negros Island.
A total of 41 volcanic earthquakes around the summit area were recorded since 5 a.m. Thursday, June 30, it said.
These included seven very shallow tortilla signals that could be associated with volcanic gas movement along with the fractures within the upper volcanic slopes, Phivolcs said.
Phivolcs said ground deformation data from continuous GPS measurements indicate short-term slight inflation of the lower and mid slopes since January 2022, consistent with continuous electronic tilt recording of inflation of southeastern flanks since mid-March 2022.
The increased seismic activity and short-term ground deformation are likely caused by shallow hydrothermal processes beneath the edifice that could generate phreatic or steam-driven eruptions from the summit crater, it added.
PHIVOLCS reminded the public that Kanlaon Volcano is at Alert Level 1, which means that it is at low-level unrest.
The local government units and the public are strongly reminded that entry into the 4-kilometer radius Permanent Danger Zone must be strictly prohibited due to the further possibilities of sudden and hazardous steam-driven or phreatic eruptions, it said.
Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ejecta from any sudden phreatic eruption can be hazardous to aircraft, Phivolcs said.*