Like any other tragedy, the earthquake struck when no one expected it.“It was a sunny morning,” Carla Manganteng, 29, told CoverStory by phone from Lagangilang, Abra. “I was in my neighbor’s house when suddenly the ground shook so violently. We immediately called everyone, told them to run outside, to a nearby open area.” 

Lagangilang is about a 20-minute drive from the earthquake’s epicenter in the municipality of Tayum. “We are fortunate that the houses in our neighborhood had only cracks in the walls and shattered glass and broken plates inside,” Manganteng said. “Our worry, what’s making us and our children lose sleep, is the scary aftershocks.”

At 8:43 a.m. on July 27, the mountainous province of Abra in northern Luzon was hit by a magnitude 7.0 earthquake, as measured by the Philippine Institute of Volcanology and Seismology (Phivolcs). Neighboring provinces  were also affected but in Abra alone, 1,729 families are in evacuation areas and 51 government buildings have been damaged. 

The province’s capital, Bangued, bore the brunt of the temblor, with a number of buildings and houses toppled or severely damaged.

Bangued resident Christine Valera, mother of two children aged 13 and 6, was in the kitchen with them when the earthquake occurred. “We immediately crawled under the table. The shaking was intense so we decided to stay there until the shaking subsided. And then we got out of the house,” she recalled.

Valera added that while her house was spared of damage, her family remained cautious, knowing that continuous aftershocks may weaken the structure. “We are camping out just to be sure,” she said. 

Related: Abra quake was less destructive but a complex seismic event

‘Like being uprooted’

Phivolcs reported that as of 8 a.m. on July 28, a total of 815 aftershocks had been recorded, of which 24 were strong enough to be felt. 

Said another Bangued resident, Neyla Manzano: “The feeling of the initial quake was like that of a plant being uprooted. The side-to-side shaking, coupled with the up-and-down movement, was just too nerve-wracking. My 7-year-old son and I had a hard time keeping our balance. Even if the aftershocks were less intense, they’re still worrisome.”

An earthquake’s destructive force depends not only on its strength (magnitude) and distance from the epicenter but also on its depth. Seismic waves from a deep earthquake (or deeper than 60 kilometers) have to travel farther to the surface, losing energy along the way.

On the other hand, as explained by Phivolcs director Renato Solidum in an interview, a shallow earthquake like the one that struck Abra—located 15 km deep—tends to cause more damage as more of the earthquake’s energy makes it to the surface, causing far greater destruction than if it occurred deeper underground. 

Solidum said earthquake damage to buildings and structures may be influenced by the type of soil they are sitting on: the softer the soil type, the greater the shaking or amplification of waves produced by an earthquake. As a result, building damage tends to be greater in areas of soft sediments.

Also, Abra is located in one of the regions in Luzon made seismically active by the presence of faults that include the northern segments of the Philippine Fault, Abra River Fault, West Ilocos Fault System, and Naglibacan Fault. 

Wednesday’s earthquake was caused by a movement along the Abra River Fault, Solidum said.

Clean water needed

The main concern of the affected families at the moment is the supply of clean water, said Valera. 

“The one supplying our area had to temporarily stop operations as the water turned muddy. Good thing we still have containers with purified water, although there are also deep wells here with water we can use for cleaning and bathing,” she said.

Manzano and her neighbors are counting themselves lucky because grocery stores have remained open, and electricity and phone signals were interrupted for only a few hours after the initial quake. 

“Even the main roads were immediately cleared of debris, although some in the inner parts of the province remain partially or completely closed because of the many landslides,” she said.

Globe Telecom Inc. (Globe), Smart Communications Inc., and its parent company PLDT (PLDT-Smart) have deployed response teams to address the damage caused by the earthquake to their broadband infrastructure and to assist residents through free services. 

There are also free calls, free charging, and a free Wi-Fi station at Bangued Plaza in Abra, adjacent to the municipality of Lagangilang.