Phivolcs, OCD urge increased alert amid tremors in Surigao del Sur

BUTUAN CITY — Officials of the Philippine Institute of Volcanology and Seismology (Phivolcs) and the Office of Civil Defence (OCD) have told local governments and the people of Surigao del Sur to heighten their alert levels after two earthquakes rocked the province within three days.

Last July 31, a 5.7-magnitude tremor struck off the coast of Hinatuan town. It was reportedly felt at Intensity 5 in Hinatuan and Intensity 4 in Bislig City.

Three days earlier, a 5.8-magnitude quake struck off the coast of Bayabas town. It was reportedly felt at Intensity 6 in Talacogon and San Francisco towns of Agusan del Sur, and either Intensity 4 or 5 in various parts of Surigao del Sur.

Phivolcs had indicated in its bulletin that damage and aftershocks were expected from the two quakes.

Evelyn Serenado, officer in charge of the Phivolcs seismic station in Bislig City, said they continued to record aftershocks.

As of 9 a.m. on Monday, August 3, the Phivolc’s earthquakes bulletin listed more than 40 aftershocks of the Hinatuan tremor and 16 aftershocks of the Bayabas tremor.

“Several tremors were also recorded in other parts of Surigao del Sur but these could not be considered aftershocks from the Bayabas quake,” Serenado said.

She added that both tremors are movements in the Philippine trench.

“Although there’s nothing we can do to prevent Mother Earth from moving, it should be a concern and we should not be complacent as we are expecting several aftershocks,” Serenado warned.

She urged residents and authorities to be on alert and on the lookout for unusually large cracks or damage in structures.

“After the earthquake, if there are evidence of large cracks or damaged portions, these are signs that there are parts of the structure that are prone to failing, and this would continue to deteriorate as the aftershocks continue to hit, weakening the structure, which is dangerous for those living in it,” explained Serenado.

Serenado particularly asked local governments to immediately conduct a risk assessment to check all the houses in affected areas.

OCD regional director Liza R. Mazo said continued aftershocks should be a cause for vigilance, reminding local governments to “immediately check and assess the infrastructure, buildings, and houses…” in keeping with established protocols.

She said heightening the alert this early would prepare the local governments to effectively respond to a quake-induced disaster.

Mazo noted that local governments in the province are consumed by their response to the COVID-19 threat and could be facing another challenge when flash floods come with the start of the rainy season.

LZB