BY GILBERT P. BAYORAN
The Negros Occidental Provincial Disaster Management Program Division yesterday issued a warning against possible landslides in mountainous areas of the province after a series of earthquake swarms between late Monday evening to Tuesday.
As of 2:30 p.m. Tuesday, a total of 30 earthquakes were recorded all taking place near Sipalay City.
The strongest was recorded at 4:12 a.m. yesterday with a magnitude of 4.6.
Instrumental Intensity IV or moderately strong shaking was felt in Sipalay City, while Intensity I was felt in Bago City.
Provincial Disaster Risk and Reduction Management Office chief Zeaphard Gerhart Caelian said all of the earthquakes were caused by the movement of the Negros Trench which is located off the coast of Sipalay City.
But Caelian said that the quakes themselves are not a serious concern pointing out that the series of tremors are natural.
He even pointed out that an earthquake swarm is far better compared to a major earthquake can release a greater energy compared to a swarm.
However, due to the rains generated by Tropical Depression “Lannie” the softer rain-soaked ground could 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) suspected that the slide was triggered by an earthquake, as prior to the incident happening they also recorded a 2.6 magnitude tremor taking place in the area.
As for 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.*
