BY DOMINIQUE GABRIEL BAÑAGA
BACOLOOD City – Residents of or near mountainous areas in Negros Occidental must be vigilant of landslides which may be triggered by earthquakes, according to the Provincial Disaster Management Program Division (PDMPD).
Between late Monday night and 2:30 p.m. on Tuesday, a total of 30 earthquake swarms were recorded near Sipalay City, said Zeaphard Caelian, PDMPD head.
The strongest was at around 4:12 a.m. yesterday with a magnitude of 4.6.
Instrumental Intensity 4, or moderately strong shaking, was felt in Sipalay City, while Intensity 1 was felt in Bago City.
Caelian said the swarms were caused by movement along the Negros Trench located off Sipalay coast.
An earthquake swarm is a burst of earthquake activity clustered in a specific area in a short period of time due to movement of a fault.
Caelian said rains generated by Tropical Depression “Lannie” could soften ground, which could then trigger landslides.
Caelian cited the Southern Leyte mudslide in 2006; aside from torrential rains, the Philippine Institute of Volcanology and Seismology suspected it was triggered by the 2.6-magnitude tremor.
As for the effect of “Lannie” in Negros Occidental, Caelian said there was no reported flooding, although scattered rain showers were experienced./PN
