By: Ellalyn V. Ruiz
An aftershock of the magnitude six earthquake that struck Lanao del Sur last April 12 was felt as a “very strong” tremor in Bukidnon early yesterday morning.
According to the Philippine Institute of Volcanology and Seismology, at least three aftershocks were felt in some areas in Mindanao yesterday.
Phivolcs recorded an aftershock measuring magnitude-5.4 at around 4:47 a.m. It originated 10 kilometers northwest of Wao, Lanao del Sur.
Intensity 6 or “very strong” tremor was recorded in Kalilangan, Bukidnon.
Phivolcs said Intensity 5 was registered in Cagayan de Oro City. An earthquake with this intensity is described as “strong” as it is “generally felt by most people indoors or outdoors.”
Intensity 4 was recorded in Pangantucan, Kadingilan, Maramag, Damulog, Quezon, and Don Carlos, all in Bukidnon. An Intensity 4 tremor is felt “generally by people indoors and some people outdoors.”
Kabacan, North Cotabato; Talakag, Bukidnon; and Tagoloan, Misamis Oriental felt the earthquake at Intensity 3, as a “weak tremor,” and Kidapawan City at Intensity 2, as a “slightly felt” shaking.
The tremor was followed by another aftershock at 5:17 a.m. with a magnitude of 4.3.
Its origin was traced at 14 kms southwest of Wao, Lanao del Sur.
Intensity 4 was felt in Kalilangan, Bukidnon; Intensity 3 in Pangantucan, Maramag, and Valencia City in Bukidnon; and Intensity 2 in Cagayan de Oro City.
At around 10:39 a.m., Phivolcs recorded a magnitude-four aftershock with its epicenter at seven kms northeast of Wao.
This tremor was felt at Intensity 3 in Wao, Lanao and Intensity 2 in Cagayan de Oro City.
Phivolcs said the earthquakes were tectonic, which is caused by ground shaking primarily due to the sudden movement in the Earth’s plates.
The tremors were generated by the movement of a northwest trending active fault in Lanao del Sur.