SOME parts of Negros Occidental were rocked by an earthquake with a magnitude of up to 4.7, followed by some aftershocks early Monday morning, June 22, 2020.
Based on the information provided by the Philippine Institute of Volcanology and Seismology (Phivolcs), the initial tremor was measured at magnitude 4.7 with a depth of 9 kilometers and its epicenter is 16 kilometers east of La Carlota City.
Intensity 5 was reported in La Carlota City; intensity 3 in Bacolod City, and Bago City; and intensity 2 in Sipalay City.
Iloilo City also reported an intensity 1 tremor.
A second tremor, with the same magnitude of 4.7, struck an hour later at around 2:06 a.m. and still located 16 kilometers east of La Carlota City.
Both tremors were tagged as "volcano-tectonic" in origin.
Phivolcs also recorded multiple smaller earthquakes prior to the main tremors. The epicenter of the smaller and major tremors were all located at the flanks of the Mt. Kanlaon volcano.
Dr. Renato Solidum, Phivolcs director, explained even before the earthquakes took place, Mt. Kanlaon had already been placed under "Alert Level 1" due to abnormal conditions observed by volcanologists.
Solidum, however, said the tremors were caused by the movement of a fault line located below the crater of the volcano.
The Phivolcs director further explained the tremors are now getting smaller in magnitude, although they will continue monitoring the volcano's activity.
Phivolcs also revealed in a follow-up report issued at 8 a.m. Monday that they have recorded a total of 136 volcano-tectonic earthquakes during a 24-hour observation, with the strongest being recorded at magnitude 3.2 to 4.7.
Phivolcs also warned the public that since "Alert Level 1" is still in place at the volcano, entry into the 4-kilometer radius Permanent Danger Zone is strictly prohibited due to the possibilities of hazardous steam-driven or phreatic eruptions.