A series of earthquakes off the coast of Claveria in Masbate, Philippines, has kept residents on high alert as dozens of earthquakes off the coast of Claveria, Masbate, Philippines, are sending residents on edge as a number of earthquakes rocked the region in the past few days. While the ongoing seismic activity has raised concerns that a larger disaster is in the news, experts say there has been little indication of a major earthquake or volcanic eruption.
The Philippine Institute of Volcanology and Seismology (PHIVOLCS) has reported an earthquake swarm, a natural seismic phenomenon that is different from the usual pattern of earthquakes followed by aftershocks.
More Than 50 Earthquakes Recorded
The earthquake swarm started on July 13 and at least 54 offshore earthquakes have been reported near Claveria, Masbate, PHIVOLCS said in a statement. The strongest so far was magnitude 5.4, followed by many smaller tremors.
The seismic activity has continued with a magnitude 4.7 earthquake recorded on Tuesday afternoon, and a number of weaker quakes. But authorities said the swarm is still active and residents should expect more aftershocks.
Despite the repeated tremors, PHIVOLCS confirmed that there is no tsunami threat associated with the ongoing seismic activity.
What is an Earthquake Swarm?
Unlike a typical earthquake sequence, where one major earthquake is followed by smaller aftershocks, an earthquake swarm is composed of multiple earthquakes of similar magnitude in a relatively short period in the same area. There is no single major earthquake that sets off the rest.
According to PHIVOLCS, earthquake swarms occur when stress beneath the Earth's surface is released gradually through repeated smaller earthquakes instead of one powerful rupture.
Former PHIVOLCS Director and Science Secretary Renato Solidum Jr. has said that earthquake swarms are common in tectonically active countries like the Philippines and do not automatically indicate that a devastating earthquake is imminent.
Why is Masbate having this activity?
Masbate lies along the Philippine Fault Zone, one of the country’s most active fault systems. The offshore area around Claveria has several active faults that regularly produce seismic activity.
PHIVOLCS believes the current earthquake swarm is the result of tectonic movement along these active faults rather than volcanic activity. Such earthquakes are not linked to volcanic unrest, officials said.
Would a bigger earthquake follow?
Scientists say an earthquake swarm does not necessarily mean a stronger earthquake is on the way.
Most swarms subside slowly without a major earthquake. However, given that the Philippines is in the middle of the Pacific Ring of Fire, one of the most seismically active regions in the world, experts cannot completely rule out the possibility of a larger earthquake.
PHIVOLCS continues round-the-clock monitoring and will update on seismic conditions as they change.
Safety Measures for Residents
Authorities have advised people in Masbate and nearby areas to be prepared by:
Staying alert for aftershocks. Following official advisories from PHIVOLCS and local governments. Checking homes and buildings for structural damage after strong shaking. Keeping emergency kits ready. Preparing family evacuation plans. Practicing the “Drop, Cover, and Hold On” earthquake safety procedure.
And officials also reminded coastal residents that although no tsunami warning has been issued, residents should follow official evacuation orders if conditions change.
A Seismically Active Region
Masbate has already experienced destructive earthquakes before, such as the magnitude 6.6 earthquake in August 2020, which caused deaths and extensive damage to the province that caused billions of dollars in damage.
Even though the current earthquake swarm has understandably raised public concern, experts are quick to emphasize that it is a manifestation of the country’s active tectonic environment and not a warning of an imminent disaster. The authorities keep an eye on the situation closely and residents are advised to keep up with the situation via official reports.
