Strong and shallow M6.4 earthquake hits Luzon, Philippines

A strong earthquake, registered by the USGS as M6.4, hit Abra Province, Luzon, Philippines at 14:59 UTC on October 25, 2022. The agency is reporting a depth of 27.3 km (17 miles). EMSC is reporting M6.4 at a depth of 18 km (11.2 miles).

The epicenter was located 11.5 km (7.1 miles) ENE of Dolores (population 2 378), 46.1 km (28.6 miles) ENE of Bantay (population 10 091), 46.6 km (28.9 miles) ENE of Vigan (population 48 545), 47.4 km (29.4 miles) NW of Pasil (population 10 109), and 96.8 km (60.2 miles) W of Tuguegarao (population 115 105).

108 000 people are estimated to have felt very strong shaking, 845 000 strong, and 2 062 000 moderate.

Based on all available data, there is no tsunami threat from this earthquake, NWS PTWC said.

The USGS issued a Green alert for shaking-related fatalities and economic losses. There is a low likelihood of casualties and damage.

Overall, the population in this region resides in structures that are a mix of vulnerable and earthquake resistant construction. The predominant vulnerable building types are unknown/miscellaneous types and heavy wood frame construction.

Recent earthquakes in this area have caused secondary hazards such as landslides and liquefaction that might have contributed to losses.

As of 06:00 LT on October 26 (22:00 UTC, October 25), PHIVOLCS registered a total of 368 aftershocks with magnitudes ranging from 1.4 to 4. Of these, at least 46 were located while 4 were felt.

By 10:00 LT on October 26 (02:00 UTC), PHIVOLCS registered 409 aftershocks. At least 81 were located and 5 were felt.

Abra Governor Dominic Valera has suspended classes in schools, both public and private, and work in all government offices on Wednesday, the Philippine News Agency reports.

National Disaster Risk Reduction and Management Council (NDRRMC) said at least two roads were damaged while power was knocked out in parts of Northern Luzon.

In its initial report, the NDRRMC noted power interruptions in the town of Allacapan and in villages in the eastern part of Gattaran town, both in Cagayan, due to a cut line and transformer problem.

The NDRRMC also said a national road in Labben and a local road in Centro East, both in Allacapan, were damaged. One house was reported damaged in Aparri, Cagayan.

At least 5 people were injured.

President Ferdinand R. Marcos called on the public to stay safe and vigilant. “Everyone is advised to keep out of tall structures.”

Estimated population exposure to earthquake shaking

Selected cities exposed

Regional seismicity

Featured image credit: TW/SAM, Google