A minor earthquake with a magnitude of 2.4 struck near Cagayancillo in Palawan on July 5 at 1:55 p.m., according to the Philippine Institute of Volcanology and Seismology (Phivolcs).

Its epicenter was located at 09.40°N, 121.47°E, approximately 36 kilometers southeast of Cagayancillo, with a depth of 19 kilometers.

This latest tremor follows a series of notable earthquakes that shook the waters of Palawan in June. Despite the province being outside the country’ typical earthquake belt, these events have underscored the region’s latent seismic potential.

In an article posted on Temblor.net by Department of Science and Technology (DOST) scientists, including Deo Carlo Llamas, Jonard Jhon Acid, Jeffrey Perez, Ishmael Narag, John Patrick Naig, and Crystel Jade Legazpi, the June 11, earthquake with a magnitude of 5.1 in Roxas was highlighted.

This event, occurring at 2:58 p.m., was followed by another tremor with a magnitude of 4.2 in Coron on June 13.

These occurrences not only surprised residents but also prompted a rapid reassessment of Palawan’s seismic activity.

The scientists conducted a thorough review of historical earthquake data, Phivolcs earthquake catalogs, and high-resolution bathymetric maps, revealing that active faults nearby could impact Palawan despite its apparent stability.

They emphasized that the province can experience shaking from large earthquakes that strike elsewhere in the Philippines.

The Temblor article noted that Palawan’s strongest recorded earthquake occurred on December 19, 1940, with a magnitude of 5.9.

More recent moderate tremors, ranging from 3.9 to 4.7, were recorded between 2013 and 2015, mostly offshore and largely unfelt by residents.

However, a magnitude 4.7 tremor was felt in Bataraza town on October 12, 2015.

The scientists explained that Palawan’s earthquakes result from elastic strain that can still build up in Earth’s crust far from active plate boundaries, due to tectonic stress from surrounding regions extending into Palawan.

This accumulates and is eventually released through fault movement, although at a much slower rate compared to regions on active plate boundaries.

Following the June 11 tremor, the epicenter was identified within the northwest Sulu Sea basin, around 90 kilometers southwest of Palawan.

Scientific calculations indicated that the tremor resulted from movement along a reverse fault, involving a northeast-southwest trending, gently dipping fault plane 10 kilometers below the surface.

Phivolcs continues to monitor seismic activity in the region, ensuring the safety and preparedness of the residents of Palawan.