Tectonic, not volcanic, quakes hit Malaybalay, Valencia – PhiVolcsPosted: April 6, 2011
MALAYBALAY CITY – The five earthquake events felt in Malaybalay and Valencia cities since April 1 were all of tectonic origin, not volcanic, Marcial Labininay, officer-in-charge of the Philippine Institute of Volcanology and Seismology (PhiVolcs) Cagayan de Oro (Malasag) Earthquake and Volcano Monitoring Unit, said.
Labininay clarified that the tremors were not caused by volcanic activity but by movements in active faults in the area.
Jovy Ellacone of the Valencia City Disaster Risk Reduction and Management Council told Bukidnon News the quakes left no damages.
Per report by Ruby Balistoy of the Philippine Information Agency in Bukidnon, residents of Valencia and Malaybalay Cities in Bukidnon felt at least two “very shallow andmild quakes” on April 5.
The earthquake events were recorded on:
– April 2, about 6:30 p.m., epicenter at 7.79 degrees North, 125.11 degrees East, 28 km. South and one (1) degree East of Malaybalay City, magnitude 3.2, Intensity II for both Malaybalay and Valencia cities.
– April 3, about 7:11a.m., epicenter at 8.04 degrees North, 125.06 degrees East, 20km. South, 14 degrees East of Malaybalay City, magnitude 3.0, Intensity I in Valencia City.
– April 3, about 7:23a.m., epicenter at 7.87 degrees North, 125.01 degrees East, 40 km. South, 15 degrees West of Malaybalay City, magnitude 3.0, Intensity II in Malaybalay City.
– April 5, 11.42a.m., epicenter at 7.87 degrees North, 124.82 degrees East, 50 km. South and 8.39 degrees West of Malaybalay City.
– April 5, at 1:25p.m., epicenter at 7.78 degrees North, 125 degrees East, 49 km. South and 14 degrees West of Malaybalay City.
With the same depth of .001 km., the latest quakes, on April 5, registered at magnitude of 3.5, Intensity III in Valencia City and Intensity II in Malaybalay City.
Also, on March 28, a mild quake was also felt in Malaybalay City at 1:32 p.m., epicenter at 73 km., East of Cagayan de Oro City, magnitude 4.0, Intensity II, also in Malaybalay City.
According to the Phivolcs website, there is a Cabanglasan fault and a Central Mindanao fault that cross Bukidnon (check this map). In the same map, a portion near the vicinity of Malaybalay and neighboring areas is shown to be prone to liquefaction, or the “phenomenon in which the strength and stiffness of a soil is reduced by earthquake shaking or other rapid loading.” (Bukidnon News with a report from PIA Bukidnon)