• RICHARD T. CABALLERO JR.
With the multiple recent tremors felt in several parts of the Philippines, including Negros Occidental, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) Negros Occidental reported that their intensity meter, which is supposed to monitor the shaking of the ground, is under maintenance.
PHIVOLCS Negros Occidental Science Research Specialist Engr. Pearly Sianson said during a media interview that at the moment, their intensity meter is not operational and is under maintenance.
“Our intensity meter is under maintenance; we only receive reports for reported intensities, which are based only on people’s experience,” she explained.
Sianson further explained that the authorities are measuring the intensities using two approaches. One is on reported intensities, which measure an earthquake’s effects on people, structures, and the environment through observation and surveys.
On the other hand, instrumental intensity is an objective measurement based on ground motion data collected by seismographs or intensity meters.
The lack of equipment has resulted in a slow-paced report of intensities in the province.
After the magnitude 7.4 earthquake that struck Manay, Davao Oriental, which was felt in the province on October 10, PHIVOLCS Negros Occidental only relied on reported intensities due to the absence of instrumental detection that was supposed to tell the accurate force of the underground activity.
As of the press time, the authorities were only relying on reported intensities while the repair of the intensity meter is underway.*
