MANILA, Philippines — The Department of Science and Technology-Philippine Institute of Volcanology and Seismology (DOST-Phivolcs) has recorded a sequence of small earthquakes in the Bicol region following a small shallow-seated earthquake with a magnitude of 4.3 and depth of 4 kilometers occurred at 10:08 p.m. on October 14.
The location of the epicenter of the 4.3 magnitude quake was determined to be at 13.65 north latitude and 123.14 east longitude or at 3 kilometers North and 75 kilometers west of Canaman, Camarines Sur.
A total of 27 earthquakes were recorded by the nearest DOST-Phivolcs earthquake monitoring station located in San Jose, Camarines Sur (Station Code: SCSP).
Magnitude ranges from 1.7 to 4.3 with crustal shallow depths between 1 to 40 kilometers.
The last recorded event associated with this earthquake sequence was at 1:22 a.m. on Monday, October 18.
There was no similar event that followed as of 6:00 a.m.
Phivolcs also recorded ten events that were felt at various intensities in the provinces of Camarines Norte, Camarines Sur and Albay.
Calculation of the intensity distribution for the first event was performed using the Rapid Earthquake Damage Assessment System (Redas) software using the latest calculated parameters of the earthquake, according to the statement released by the DOST.
Results show that the magnitude and shallow depth of this inland event has the potential to cause damage in the general vicinity of the epicenter.
The department said it immediately informed the Office of Civil Defense (OCD) about this during the information release of the first event.
The DOST also noted that social media posts indicate that the event was widely felt with unconfirmed observations of non-structural damage (glass door was damaged) and damage to building content.
This prompted OCD to instruct their regional office to investigate the reported damage in the affected areas.
DOST-Phivolcs said that based on the collected data, this sequence of events, showing no identifiable large event, can be considered as an earthquake swarm that may occur in a tectonically active region, as suggested by sparse seismicity in this area of the Bicol region.
DOST-Phivolcs said it will closely monitor any progress of this earthquake activity and will continue to post updated information at the Phivolcs Official website.