Aftershocks continued to shake the municipality of Calatagan in Batangas after it was hit by a magnitude 6.6 earthquake early Saturday, the state seismologist reported.
The Philippine Institute of Volcanology and Seismology (Phivolcs) recorded 24 aftershocks as of 9:16 a.m., with the strongest at magnitude 5.5, which immediately followed the first intense tremor. The majority of the aftershocks were recorded at magnitude 2.
In its initial earthquake bulletin, Phivolcs reported the quake, which was tectonic in origin, at 4:49 a.m. at a depth of 116 km.
The tremor was first reported at a magnitude of 6.7 but was later reduced to magnitude 6.6.
The Provincial Risk Reduction and Management Office (PDRRMO) of Batangas was looking for possible damage and landslide due to the early heavy ground movement, the Philippine Broadcasting Service said in a report.
Intensity V, considered by Phivolcs as “strong”, was felt in Calapan City and Puerto Galera, Oriental Mindoro; Sablayan and Magsaysay, Occidental Mindoro; and Tagaytay City, Carmona, and Dasmariñas City, Cavite.
Intensity IV or “moderately strong” was recorded in Manila, Marikina City, Makati City, Taguig City, Quezon City, Pasay City, Valenzuela City, Tagaytay City in Cavite; San Mateo in Rizal, and Batangas City and Talisay City in Batangas.
Magnitude measures the energy released from the source of the quake while intensity measures the strength of shaking produced by the tremor at a certain location.