A magnitude 4.5 aftershock hits Hinatuan, Surigao del Sur on Friday, recording an Intensity III and Instrumental Intensity I in the City of Bislig. (Photo from Phivolcs)
MANILA, Philippines — The people of Surigao del Sur felt minor temblors as three tectonic earthquakes were recorded by the Philippine Institute of Volcanology and Seismology (Phivolcs) on Friday.
Based on Phivolcs’ earthquake information, Intensity III and Instrumental Intensity I were recorded in the City of Bislig when a magnitude 3.7 temblor occurred in the waters off Hinatuan at 2:10 a.m.
In INQUIRER.net’s previous interview with Phivolcs Science Research Analyst Lara Guianan, it was explained that an earthquake intensity is based on the ground motion actually felt and reported by people in the affected area, while instrumental intensity is the quake’s strength as measured by an intensity scale.
According to Phivolcs, the shaking had a 29-kilometer depth of focus. The agency indicated that it was an aftershock of the magnitude 7.4 earthquake, which jolted the same area on Dec. 2.
At 3:27 a.m., the City of Bislig once again felt a temblor—this time, in magnitude 4.5.
Intensity I was felt in the city.
The shaking was recorded in the waters off Marihatag and had a 12-kilometer depth of focus.
Meanwhile, a magnitude 4.0 earthquake struck the waters off Cagwait at 11:25 a.m. It had a three-kilometer depth of focus.
Phivolcs said Intensity III was felt in the City of Tandang.
An instrumental Intensity I was also reported in its neighboring provinces as the shaking was likewise felt in Hinunangan in Southern Leyte, the City of Surigao in Surigao del Norte, and the City of Cabadbaran in Agusan del Norte.
No damage or aftershocks are expected from the temblors, Phivolcs noted.
Aside from the magnitude 7.4 earthquake in Hinatuan on Saturday, a magnitude 6.8 temblor hit Cagwait, also in Surigao del Sur, on Monday.
Based on recent reports, Phivolcs has already recorded thousands of aftershocks in the province.