San remigio: Coastal subsidence has been observed in Barangay Hagnaya, San Remigio, Cebu after the magnitude 6.9 offshore earthquake jolted the province last Sept. 30, the Philippine Institute of Volcanology and Seismology (Phivolcs) said Wednesday. This has caused several buildings and infrastructure to be partly submerged by seawater, the agency said in a social media post.
According to PhilippineS News Agency, Phivolcs Director Teresito Bacolcol explained in an online interview that subsidence decreases the coastal elevation, making it prone to flooding or seawater intrusion during high tides. He noted that subsidence is sometimes a result of crustal movements during earthquakes. Bacolcol clarified that not all offshore earthquakes would lead to subsidence, but this commonly happens in areas near the fault that produced the tremors.
The magnitude 6.9 offshore quake was generated by the Bogo Bay Fault in Bogo City, Cebu. Bacolcol advised local government units to reassess and monitor affected coastal areas for changes in elevation or flooding. He recommended updating hazard maps and revisiting Comprehensive Land Use Plans.
Meanwhile, Phivolcs continues to remind the public to prepare for possible strong aftershocks and to avoid structures prone to damage and collapse. As of Wednesday noon, Phivolcs recorded 9,204 aftershocks with magnitudes ranging from 1 to 5.1. At least 38 of these were felt, and 1,682 were plotted or located.
