THE number of aftershocks to the strong quakes in Cotabato has diminished, Philippine Institute of Volcanology and Seismology (Phivolcs) Officer-in-Charge Renato U. Solidum, Jr. said.

As of 7 a.m. on Tuesday, a total of 2,870 aftershocks had been recorded, with 1,304 plotted or located by instruments and 208 “felt” by people or with instrumental intensities since the magnitude 6.3 quake on October 16.

The magnitude 6.3 quake was followed by magnitude 6.6 on October 29 and magnitude 6.5 on October 31, with the last two claiming at least 17 lives, injuring hundreds, and damaging structures in the affected parts in the southern Philippine region.

Aftershocks from October 31 ranged from magnitude 1.4 to 5.0.

Solidum said the number of aftershocks has diminished in terms of number but the area remained “highly stressed.”

Aftershocks are expected to persist for weeks and did not discount the possibility of another strong quake.

Solidum said that the series of strong tremors originated from the Cotabato Fault System made up of the: M’lang Fault, Makilala-Malungon Fault, North Columbio Fault, South Columbio Fault, and the western extension of the Mindanao Fault or the Cotabato-Sindangan Fault.

He said that most likely, the strong quakes were caused by the movement of the M’lang Fault and Makilala-Malungon Fault. DIVINA NOVA JOY DELA CRUZ