Magnitude 4.5 aftershock jolts Bohol, Cebu

By: Jeannette I. Andrade - 11 years ago

Image by Phivolcs

First posted 2:01 pm | Tuesday, November 12th, 2013

MANILA, Philippines — A magnitude 4.5 earthquake jolted on Tuesday afternoon Bohol and Cebu provinces, which were still reeling from the effects of the magnitude 7.2 temblor last October 15.

The Philippine Institute of Volcanology and Seismology (Phivolcs) recorded the earthquake at around 1:21 p.m. Tuesday, with its epicenter located at 31 kilometers northeast of Tagbilaran City. The earthquake is actually an aftershock, one of the many, from the powerful October 15 tremor.

The tectonic earthquake had a depth of focus of nine kilometers and was felt at intensity V in San Isidro town in Bohol and Mandaue City; intensity IV in Cebu City; and intensity III at Lapu-Lapu City and Calape town in Bohol.

Based on the Phivolcs Earthquake Intensity Scale (PEIS), an intensity V is strong and generally felt by most people indoors and outdoors. Strong shaking and rocking is felt throughout a building where hanging objects swing violently and dining utensils clatter. Small, light and unstable objects may topple over while liquids spill from open containers. Vehicles can be observed to rock.

Magnitude 4 to 5 earthquakes are described as “feeble shocks” where damage to property is not usually reported.

Magnitude is the measurement of the energy released at the source of the earthquake while intensity illustrates the strength of the shaking through visible effects of the tremor on objects, people and the general environment.

Tuesday’s magnitude 4.5 earthquake was one of the strongest aftershocks, out of 3,496, recorded by the Phivolcs in the past two weeks.

Meanwhile Phivolcs director Renato Solidum released an advisory Tuesday stating that the agency has not issued any tsunami warning for Samar province or any other part of the country.

“No threat of tsunami exists for the Philippines,” he said, debunking tsunami rumors that circulated in Calbayog City in Samar province, which sent residents traumatized by typhoon Yolanda fleeing to higher ground.

Phivolcs is the only agency in the country that issues tsunami warnings.