Close to 1,000 aftershocks were so far recorded, following the powerful 6.9-magnitude earthquake that rocked parts of Mindanao on December 15.
According to Philippine Institute of Volcanology and Seismology (Phivolcs) science research assistant Gail Rivera, 957 aftershocks ranging between 1.4-magnitude and 5.2-magnitude were recorded as of 5 a.m., Monday.
Of these aftershocks, Rivera said 130 were plotted close to the epicenter of the 6.9-magnitude earthquake in the municipality of Matanao, Davao del Sur. At least 41 tremors were felt.
The strongest aftershock with a magnitude of 5.2 was documented at around 3:09 p.m. last Sunday.
The Tangbulan Fault may have caused the earthquake, Rivera pointed out.
The 6.9-magnitude shallow quake was the fifth one above magnitude 6 that rocked Mindanao in the past two months. Strong earthquakes occurred in Cotabato and nearby provinces on October 16 (6.3-magnitude), October 29 (6.6 and 6.1-magnitude), and October 31 (6.5-magnitude).
Although it is below magnitude 6, a moderate earthquake of magnitude 5.9 also shook the province of Bukidnon last November 18. (Ellalyn De Vera-Ruiz)