PHIVOLCS: Magnitude 6.9 quake in Cebu caused by 400-year-old dormant fault
The magnitude 6.9 earthquake that rocked Cebu was caused by a fault that moved for the first time in 400 years, the Philippine Institute of Volcanology and Seismology said.
At 9:59 p.m. on Sept. 30, a quake jolted the area with an epicenter 19 kilometers off Bogo City.
"At least in the last 400 years, 'yun pong fault na nag-generate nito, ngayon lang po siya gumalaw kaya siya medyo malakas," PHIVOLCS chief science research specialist Dr. Winchelle Ian Sevilla said in a press briefing on Oct. 1.
Sevilla noted that the agency has not traced a fault line in the epicentral area, as the fault is underwater and generates only small earthquakes that aren't felt by people in the area.
"Ngayon lang nagkaroon ng malaking earthquakes o yung pag-galaw," he said.
Cebu remains seismically active as it is in an area with many fault lines, Sevilla added.
"Among earthquake sources are Bogo Fault, Daanbantayan Lineament, and the Cebu Fault System. There are also local inland and offshore faults, some concealed by recent deposits, capable of generating earthquakes ranging from minor to strong magnitudes," PHIVOLCS stated in a press release.
Sevilla clarified that the 400-year-old dormant fault is probably a different one from the ones the agency listed in its release for general information.
A quick response team has been deployed to determine which fault generated the quake.
The Department of Public Works and Highways has placed the initial estimated damage from the earthquake at P2 billion.
Office of Civil Defense Assistant Secretary Bernardo Rafaelito Alejandro IV told PTV in an interview that the death toll has reached 69 as of 12:11 p.m.
