NEGROS Occidental Provincial Disaster Management Program Division (PDMPD) head Zeaphard Caelian has warned residents living near mountainous areas to be on alert amid possible landslides triggered by earthquakes.

Caelian issued the warning Tuesday, October 5, after a series of earthquakes were felt between late Monday evening (October 4) and Tuesday (October 5).

As of 2:30 p.m. Tuesday, October 5, a total of 30 earthquakes were recorded in Sipalay City alone. The strongest one was at 4:12 a.m. with a magnitude of 4.6, Caelian said.

The quake was felt at Instrumental Intensity IV, or moderately strong shaking, in Sipalay City, and Intensity I in Bago City also on Tuesday.

Caelian said all of the earthquakes were caused by the movement along the Negros Trench, which is located off the coast of Sipalay City.

According to the PDMPD head, the quakes themselves are not a serious concern, pointing out that the series of tremors are natural.

He said an earthquake swarm is far better compared to a major earthquake that can release greater energy compared to the former.

But due to the rains generated by Tropical Depression "Lannie," the rain-soaked ground is softer, which could then trigger landslides.

Caelian pointed the example of the Southern Leyte mudslide in 2006, wherein aside from the torrential rains, geologists from the Philippine Institute of Volcanology and Seismology (Phivolcs) also suspected that the slide was triggered by an earthquake, as before the incident happened, they also recorded a 2.6-magnitude tremor taking place in the area.

As to the effect of "Lannie" to the province, Caelian said they did not record any flooding incidents when the storm passed by the island on Monday night, although scattered rain showers were experienced throughout the evening.